Merge branch 'IonAgorria-dinamic-prices' into develop

htdocs/core/class/html.form.class.php

@@ -1906,7 +1906,7 @@ class Form
 
         $sql = "SELECT p.rowid, p.label, p.ref, p.price, p.duration,";
         $sql.= " pfp.ref_fourn, pfp.rowid as idprodfournprice, pfp.price as fprice, pfp.quantity, pfp.remise_percent, pfp.remise, pfp.unitprice,";
-        $sql.= " s.nom as name";
+        $sql.= " pfp.fk_price_expression, pfp.fk_product, pfp.tva_tx, s.nom as name";
         $sql.= " FROM ".MAIN_DB_PREFIX."product as p";
         $sql.= " LEFT JOIN ".MAIN_DB_PREFIX."product_fournisseur_price as pfp ON p.rowid = pfp.fk_product";
         if ($socid) $sql.= " AND pfp.fk_soc = ".$socid;
@@ -1943,6 +1943,7 @@ class Form
         $result=$this->db->query($sql);
         if ($result)
         {
+            require_once DOL_DOCUMENT_ROOT.'/product/class/priceparser.class.php';
 
             $num = $this->db->num_rows($result);
 
@@ -1987,6 +1988,17 @@ class Form
                 {
                     $outqty=$objp->quantity;
 					$outdiscount=$objp->remise_percent;
+                    if (!empty($objp->fk_price_expression)) {
+                        $priceparser = new PriceParser($this->db);
+                        $price_result = $priceparser->parse_product_supplier($objp->fk_product, $objp->fk_price_expression, $objp->quantity, $objp->tva_tx);
+                        if ($price_result >= 0) {
+                            $objp->fprice = $price_result;
+                            if ($objp->quantity >= 1)
+                            {
+                                $objp->unitprice = $objp->fprice / $objp->quantity;
+                            }
+                        }
+                    }
                     if ($objp->quantity == 1)
                     {
 	                    $opt.= price($objp->fprice,1,$langs,0,0,-1,$conf->currency)."/";
@@ -2075,7 +2087,7 @@ class Form
 
         $sql = "SELECT p.rowid, p.label, p.ref, p.price, p.duration,";
         $sql.= " pfp.ref_fourn, pfp.rowid as idprodfournprice, pfp.price as fprice, pfp.quantity, pfp.unitprice,";
-        $sql.= " s.nom as name";
+        $sql.= " pfp.fk_price_expression, pfp.fk_product, pfp.tva_tx, s.nom as name";
         $sql.= " FROM ".MAIN_DB_PREFIX."product as p";
         $sql.= " LEFT JOIN ".MAIN_DB_PREFIX."product_fournisseur_price as pfp ON p.rowid = pfp.fk_product";
         $sql.= " LEFT JOIN ".MAIN_DB_PREFIX."societe as s ON pfp.fk_soc = s.rowid";
@@ -2100,6 +2112,7 @@ class Form
             }
             else
             {
+                require_once DOL_DOCUMENT_ROOT.'/product/class/priceparser.class.php';
                 $form.= '<option value="0">&nbsp;</option>';
 
                 $i = 0;
@@ -2114,6 +2127,17 @@ class Form
                     }
                     $opt.= '>'.$objp->name.' - '.$objp->ref_fourn.' - ';
 
+                    if (!empty($objp->fk_price_expression)) {
+                        $priceparser = new PriceParser($this->db);
+                        $price_result = $priceparser->parse_product_supplier($objp->fk_product, $objp->fk_price_expression, $objp->quantity, $objp->tva_tx);
+                        if ($price_result >= 0) {
+                            $objp->fprice = $price_result;
+                            if ($objp->quantity >= 1)
+                            {
+                                $objp->unitprice = $objp->fprice / $objp->quantity;
+                            }
+                        }
+                    }
                     if ($objp->quantity == 1)
                     {
                         $opt.= price($objp->fprice,1,$langs,0,0,-1,$conf->currency)."/";

htdocs/core/modules/modDynamicPrices.class.php

@@ -0,0 +1,122 @@
+<?php
+/* Copyright (C) 2014      Ion Agorria          <ion@agorria.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ *  \defgroup   produit     Module dynamic prices
+ *  \brief      Module to manage dynamic prices in products
+ *  \file       htdocs/core/modules/modDynamicPrices.class.php
+ *  \ingroup    produit
+ *  \brief      File to describe module to manage dynamic prices in products
+ */
+include_once DOL_DOCUMENT_ROOT .'/core/modules/DolibarrModules.class.php';
+
+
+/**
+ *  Class descriptor of DynamicPrices module
+ */
+class modDynamicPrices extends DolibarrModules
+{
+
+    /**
+	 *   Constructor. Define names, constants, directories, boxes, permissions
+	 *
+	 *   @param      DoliDB		$db      Database handler
+     */
+    function __construct($db)
+    {
+        $this->db = $db;
+        $this->numero = 2200;
+
+        $this->family = "products";
+        // Module label (no space allowed), used if translation string 'ModuleXXXName' not found (where XXX is value of numeric property 'numero' of module)
+        $this->name = preg_replace('/^mod/i','',get_class($this));
+        $this->description = "Enable the usage of math expressions for prices";
+        $this->version = 'experimental';                        // 'experimental' or 'dolibarr' or version
+        // Key used in llx_const table to save module status enabled/disabled (where MYMODULE is value of property name of module in uppercase)
+        $this->const_name = 'MAIN_MODULE_'.strtoupper($this->name);
+        // Where to store the module in setup page (0=common,1=interface,2=others,3=very specific)
+        $this->special = 0;
+        // Name of image file used for this module.
+        $this->picto='technic';
+
+        // Data directories to create when module is enabled
+        $this->dirs = array();
+
+        // Config pages
+        //-------------
+        //$this->config_page_url = array("dynamicprices.php@dynamicprices");
+
+        // Dependancies
+        //-------------
+        $this->depends = array();
+        $this->requiredby = array();
+        $this->langfiles = array("other");
+
+        // Constantes
+        //-----------
+        $this->const = array();
+
+        // New pages on tabs
+        // -----------------
+        $this->tabs = array();
+
+        // Boxes
+        //------
+        $this->boxes = array();
+
+        // Permissions
+        //------------
+        $this->rights = array();
+        $this->rights_class = 'dynamicprices';
+        $r=0;
+    }
+
+
+    /**
+	 *		Function called when module is enabled.
+	 *		The init function add constants, boxes, permissions and menus (defined in constructor) into Dolibarr database.
+	 *		It also creates data directories
+	 *
+     *      @param      string	$options    Options when enabling module ('', 'noboxes')
+	 *      @return     int             	1 if OK, 0 if KO
+     */
+    function init($options='')
+    {
+        // Prevent pb of modules not correctly disabled
+        //$this->remove($options);
+
+        $sql = array();
+
+        return $this->_init($sql,$options);
+    }
+
+    /**
+	 *		Function called when module is disabled.
+	 *      Remove from database constants, boxes and permissions from Dolibarr database.
+	 *		Data directories are not deleted
+	 *
+     *      @param      string	$options    Options when enabling module ('', 'noboxes')
+	 *      @return     int             	1 if OK, 0 if KO
+     */
+    function remove($options='')
+    {
+		$sql = array();
+
+		return $this->_remove($sql,$options);
+    }
+
+}

htdocs/fourn/ajax/getSupplierPrices.php

@@ -48,7 +48,7 @@ if (! empty($idprod))
 	$sql = "SELECT p.rowid, p.label, p.ref, p.price, p.duration,";
 	$sql.= " pfp.ref_fourn,";
 	$sql.= " pfp.rowid as idprodfournprice, pfp.price as fprice, pfp.remise_percent, pfp.quantity, pfp.unitprice, pfp.charges, pfp.unitcharges,";
-	$sql.= " s.nom as name";
+	$sql.= " pfp.fk_price_expression, pfp.tva_tx, s.nom as name";
 	$sql.= " FROM ".MAIN_DB_PREFIX."product_fournisseur_price as pfp";
 	$sql.= " LEFT JOIN ".MAIN_DB_PREFIX."product as p ON p.rowid = pfp.fk_product";
 	$sql.= " LEFT JOIN ".MAIN_DB_PREFIX."societe as s ON s.rowid = pfp.fk_soc";
@@ -66,11 +66,24 @@ if (! empty($idprod))
 
 		if ($num)
 		{
+            require_once DOL_DOCUMENT_ROOT.'/product/class/priceparser.class.php';
 			$i = 0;
 			while ($i < $num)
 			{
 				$objp = $db->fetch_object($result);
 
+                if (!empty($objp->fk_price_expression)) {
+                    $priceparser = new PriceParser($db);
+                    $price_result = $priceparser->parse_product_supplier($idprod, $objp->fk_price_expression, $objp->quantity, $objp->tva_tx);
+                    if ($price_result >= 0) {
+                        $objp->fprice = $price_result;
+                        if ($objp->quantity >= 1)
+                        {
+                            $objp->unitprice = $objp->fprice / $objp->quantity;
+                        }
+                    }
+                }
+
 				$price = $objp->fprice * (1 - $objp->remise_percent / 100);
 				$unitprice = $objp->unitprice * (1 - $objp->remise_percent / 100);
 

htdocs/fourn/class/fournisseur.product.class.php

@@ -27,6 +27,7 @@
 
 require_once DOL_DOCUMENT_ROOT.'/product/class/product.class.php';
 require_once DOL_DOCUMENT_ROOT.'/fourn/class/fournisseur.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/class/priceparser.class.php';
 
 
 /**
@@ -55,6 +56,8 @@ class ProductFournisseur extends Product
     var $fourn_unitprice;
     var $fourn_tva_npr;
 
+    var $fk_price_expression;
+
 
     /**
 	 *	Constructor
@@ -320,13 +323,14 @@ class ProductFournisseur extends Product
     /**
      *    Loads the price information of a provider
      *
-     *    @param	int		$rowid	        Line id
+     *    @param    int     $rowid              Line id
-     *    @return   int 					< 0 if KO, 0 if OK but not found, > 0 if OK
+     *    @param    int     $ignore_expression  Ignores the math expression for calculating price and uses the db value instead
+     *    @return   int 					    < 0 if KO, 0 if OK but not found, > 0 if OK
      */
-    function fetch_product_fournisseur_price($rowid)
+    function fetch_product_fournisseur_price($rowid, $ignore_expression = 0)
     {
         $sql = "SELECT pfp.rowid, pfp.price, pfp.quantity, pfp.unitprice, pfp.remise_percent, pfp.remise, pfp.tva_tx, pfp.fk_availability,";
-        $sql.= " pfp.fk_soc, pfp.ref_fourn, pfp.fk_product, pfp.charges, pfp.unitcharges"; // , pfp.recuperableonly as fourn_tva_npr";  FIXME this field not exist in llx_product_fournisseur_price
+        $sql.= " pfp.fk_soc, pfp.ref_fourn, pfp.fk_product, pfp.charges, pfp.unitcharges, pfp.fk_price_expression"; // , pfp.recuperableonly as fourn_tva_npr";  FIXME this field not exist in llx_product_fournisseur_price
         $sql.= " FROM ".MAIN_DB_PREFIX."product_fournisseur_price as pfp";
         $sql.= " WHERE pfp.rowid = ".$rowid;
 
@@ -351,6 +355,25 @@ class ProductFournisseur extends Product
             	$this->fk_product				= $obj->fk_product;
             	$this->fk_availability			= $obj->fk_availability;
             	//$this->fourn_tva_npr			= $obj->fourn_tva_npr; // FIXME this field not exist in llx_product_fournisseur_price
+                $this->fk_price_expression      = $obj->fk_price_expression;
+
+                if (empty($ignore_expression) && !empty($this->fk_price_expression)) {
+                    $priceparser = new PriceParser($this->db);
+                    $price_result = $priceparser->parse_product_supplier($this->fk_product, $this->fk_price_expression, $this->fourn_qty, $this->fourn_tva_tx);
+                    if ($price_result >= 0) {
+                    	$this->fourn_price = $price_result;
+                    	//recalculation of unitprice, as probably the price changed...
+	                    if ($this->fourn_qty!=0)
+	                    {
+	                        $this->fourn_unitprice = price2num($this->fourn_price/$this->fourn_qty,'MU');
+	                    }
+	                    else
+	                    {
+	                        $this->fourn_unitprice="";
+	                    }
+                    }
+                }
+
             	return 1;
             }
             else
@@ -379,7 +402,7 @@ class ProductFournisseur extends Product
         global $conf;
 
         $sql = "SELECT s.nom as supplier_name, s.rowid as fourn_id,";
-        $sql.= " pfp.rowid as product_fourn_pri_id, pfp.ref_fourn, pfp.fk_product as product_fourn_id,";
+        $sql.= " pfp.rowid as product_fourn_pri_id, pfp.ref_fourn, pfp.fk_product as product_fourn_id, pfp.fk_price_expression,";
         $sql.= " pfp.price, pfp.quantity, pfp.unitprice, pfp.remise_percent, pfp.remise, pfp.tva_tx, pfp.fk_availability, pfp.charges, pfp.unitcharges, pfp.info_bits";
         $sql.= " FROM ".MAIN_DB_PREFIX."product_fournisseur_price as pfp";
         $sql.= ", ".MAIN_DB_PREFIX."societe as s";
@@ -416,6 +439,16 @@ class ProductFournisseur extends Product
                 $prodfourn->fk_availability			= $record["fk_availability"];
                 $prodfourn->id						= $prodid;
                 $prodfourn->fourn_tva_npr						= $record["info_bits"];
+                $prodfourn->fk_price_expression     = $record["fk_price_expression"];
+
+                if (!empty($prodfourn->fk_price_expression)) {
+                    $priceparser = new PriceParser($this->db);
+                    $price_result = $priceparser->parse_product_supplier($prodid, $prodfourn->fk_price_expression, $prodfourn->fourn_qty, $prodfourn->fourn_tva_tx);
+                    if ($price_result >= 0) {
+                    	$prodfourn->fourn_price = $price_result;
+                    	$prodfourn->fourn_unitprice = null; //force recalculation of unitprice, as probably the price changed...
+                    }
+                }
 
                 if (!isset($prodfourn->fourn_unitprice))
                 {
@@ -468,7 +501,7 @@ class ProductFournisseur extends Product
         $sql = "SELECT s.nom as supplier_name, s.rowid as fourn_id,";
         $sql.= " pfp.rowid as product_fourn_price_id, pfp.ref_fourn,";
         $sql.= " pfp.price, pfp.quantity, pfp.unitprice, pfp.tva_tx, pfp.charges, pfp.unitcharges, ";
-        $sql.= " pfp.remise, pfp.remise_percent";
+        $sql.= " pfp.remise, pfp.remise_percent, pfp.fk_price_expression";
         $sql.= " FROM ".MAIN_DB_PREFIX."societe as s, ".MAIN_DB_PREFIX."product_fournisseur_price as pfp";
         $sql.= " WHERE s.entity IN (".getEntity('societe', 1).")";
         $sql.= " AND pfp.fk_product = ".$prodid;
@@ -495,6 +528,7 @@ class ProductFournisseur extends Product
             $this->fourn_tva_tx				= $record["tva_tx"];
             $this->fourn_id					= $record["fourn_id"];
             $this->fourn_name				= $record["supplier_name"];
+            $this->fk_price_expression      = $record["fk_price_expression"];
             $this->id						= $prodid;
             $this->db->free($resql);
             return 1;
@@ -506,6 +540,39 @@ class ProductFournisseur extends Product
         }
     }
 
+    /**
+     *  Sets the price expression
+     *
+     *  @param  string  $expression Expression
+     *  @return int                 <0 if KO, >0 if OK
+     */
+    function set_price_expression($expression_id)
+    {
+        global $conf;
+
+        // Clean parameters
+        $this->db->begin();
+
+        $sql = "UPDATE ".MAIN_DB_PREFIX."product_fournisseur_price";
+        $sql.= " SET fk_price_expression = ".$expression_id;
+        $sql.= " WHERE rowid = ".$this->product_fourn_price_id;
+
+        dol_syslog(get_class($this)."::set_price_expression", LOG_DEBUG);
+
+        $resql = $this->db->query($sql);
+        if ($resql)
+        {
+            $this->db->commit();
+            return 1;
+        }
+        else
+        {
+            $this->error=$this->db->error()." sql=".$sql;
+            $this->db->rollback();
+            return -1;
+        }
+    }
+
     /**
      *	Display supplier of product
      *

htdocs/includes/evalmath/README.md

@@ -0,0 +1,11 @@
+evalmath.class.php
+==================
+
+Version 1.0
+
+Taken from http://www.phpclasses.org/browse/file/11680.html, cred to Miles Kaufmann
+
+This repository is cloned for two reasons:
+
+1. To allow downloading the code without signing in to phpclasses.org.
+2. To add very small improvements to the code.

htdocs/includes/evalmath/evalmath.class.php

@@ -0,0 +1,393 @@
+<?php
+
+/*
+================================================================================
+
+EvalMath - PHP Class to safely evaluate math expressions
+Copyright (C) 2005 Miles Kaufmann <http://www.twmagic.com/>
+
+================================================================================
+
+NAME
+    EvalMath - safely evaluate math expressions
+    
+SYNOPSIS
+      include('evalmath.class.php');
+      $m = new EvalMath;
+      // basic evaluation:
+      $result = $m->evaluate('2+2');
+      // supports: order of operation; parentheses; negation; built-in functions
+      $result = $m->evaluate('-8(5/2)^2*(1-sqrt(4))-8');
+      // create your own variables
+      $m->evaluate('a = e^(ln(pi))');
+      // or functions
+      $m->evaluate('f(x,y) = x^2 + y^2 - 2x*y + 1');
+      // and then use them
+      $result = $m->evaluate('3*f(42,a)');
+      
+DESCRIPTION
+    Use the EvalMath class when you want to evaluate mathematical expressions 
+    from untrusted sources.  You can define your own variables and functions,
+    which are stored in the object.  Try it, it's fun!
+
+METHODS
+    $m->evalute($expr)
+        Evaluates the expression and returns the result.  If an error occurs,
+        prints a warning and returns false.  If $expr is a function assignment,
+        returns true on success.
+    
+    $m->e($expr)
+        A synonym for $m->evaluate().
+    
+    $m->vars()
+        Returns an associative array of all user-defined variables and values.
+        
+    $m->funcs()
+        Returns an array of all user-defined functions.
+
+PARAMETERS
+    $m->suppress_errors
+        Set to true to turn off warnings when evaluating expressions
+
+    $m->last_error
+        If the last evaluation failed, contains a string describing the error.
+        (Useful when suppress_errors is on).
+
+    $m->last_error_code
+        If the last evaluation failed, 2 element array with numeric code and extra info
+
+AUTHOR INFORMATION
+    Copyright 2005, Miles Kaufmann.
+
+LICENSE
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions are
+    met:
+    
+    1   Redistributions of source code must retain the above copyright
+        notice, this list of conditions and the following disclaimer.
+    2.  Redistributions in binary form must reproduce the above copyright
+        notice, this list of conditions and the following disclaimer in the
+        documentation and/or other materials provided with the distribution.
+    3.  The name of the author may not be used to endorse or promote
+        products derived from this software without specific prior written
+        permission.
+    
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+    DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+    INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+    STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+    POSSIBILITY OF SUCH DAMAGE.
+*/
+
+class EvalMath {
+
+    var $suppress_errors = false;
+    var $last_error = null;
+    var $last_error_code = null;
+    
+    var $v = array('e'=>2.71,'pi'=>3.14); // variables (and constants)
+    var $f = array(); // user-defined functions
+    var $vb = array('e', 'pi'); // constants
+    var $fb = array(  // built-in functions
+        'sin','sinh','arcsin','asin','arcsinh','asinh',
+        'cos','cosh','arccos','acos','arccosh','acosh',
+        'tan','tanh','arctan','atan','arctanh','atanh',
+        'sqrt','abs','ln','log');
+    
+    function EvalMath() {
+        // make the variables a little more accurate
+        $this->v['pi'] = pi();
+        $this->v['e'] = exp(1);
+    }
+    
+    function e($expr) {
+        return $this->evaluate($expr);
+    }
+    
+    function evaluate($expr) {
+        $this->last_error = null;
+        $this->last_error_code = null;
+        $expr = trim($expr);
+        if (substr($expr, -1, 1) == ';') $expr = substr($expr, 0, strlen($expr)-1); // strip semicolons at the end
+        //===============
+        // is it a variable assignment?
+        if (preg_match('/^\s*([a-z]\w*)\s*=\s*(.+)$/', $expr, $matches)) {
+            if (in_array($matches[1], $this->vb)) { // make sure we're not assigning to a constant
+                return $this->trigger(1, "cannot assign to constant '$matches[1]'", $matches[1]);
+            }
+            if (($tmp = $this->pfx($this->nfx($matches[2]))) === false) return false; // get the result and make sure it's good
+            $this->v[$matches[1]] = $tmp; // if so, stick it in the variable array
+            return $this->v[$matches[1]]; // and return the resulting value
+        //===============
+        // is it a function assignment?
+        } elseif (preg_match('/^\s*([a-z]\w*)\s*\(\s*([a-z]\w*(?:\s*,\s*[a-z]\w*)*)\s*\)\s*=\s*(.+)$/', $expr, $matches)) {
+            $fnn = $matches[1]; // get the function name
+            if (in_array($matches[1], $this->fb)) { // make sure it isn't built in
+                return $this->trigger(2, "cannot redefine built-in function '$matches[1]()'", $matches[1]);
+            }
+            $args = explode(",", preg_replace("/\s+/", "", $matches[2])); // get the arguments
+            if (($stack = $this->nfx($matches[3])) === false) return false; // see if it can be converted to postfix
+            for ($i = 0; $i<count($stack); $i++) { // freeze the state of the non-argument variables
+                $token = $stack[$i];
+                if (preg_match('/^[a-z]\w*$/', $token) and !in_array($token, $args)) {
+                    if (array_key_exists($token, $this->v)) {
+                        $stack[$i] = $this->v[$token];
+                    } else {
+                        return $this->trigger(3, "undefined variable '$token' in function definition", $token);
+                    }
+                }
+            }
+            $this->f[$fnn] = array('args'=>$args, 'func'=>$stack);
+            return true;
+        //===============
+        } else {
+            return $this->pfx($this->nfx($expr)); // straight up evaluation, woo
+        }
+    }
+    
+    function vars() {
+        $output = $this->v;
+        unset($output['pi']);
+        unset($output['e']);
+        return $output;
+    }
+    
+    function funcs() {
+        $output = array();
+        foreach ($this->f as $fnn=>$dat)
+            $output[] = $fnn . '(' . implode(',', $dat['args']) . ')';
+        return $output;
+    }
+
+    //===================== HERE BE INTERNAL METHODS ====================\\
+
+    // Convert infix to postfix notation
+    function nfx($expr) {
+    
+        $index = 0;
+        $stack = new EvalMathStack;
+        $output = array(); // postfix form of expression, to be passed to pfx()
+        $expr = trim(strtolower($expr));
+        
+        $ops   = array('+', '-', '*', '/', '^', '_');
+        $ops_r = array('+'=>0,'-'=>0,'*'=>0,'/'=>0,'^'=>1); // right-associative operator?  
+        $ops_p = array('+'=>0,'-'=>0,'*'=>1,'/'=>1,'_'=>1,'^'=>2); // operator precedence
+        
+        $expecting_op = false; // we use this in syntax-checking the expression
+                               // and determining when a - is a negation
+    
+        if (preg_match("/[^\w\s+*^\/()\.,-]/", $expr, $matches)) { // make sure the characters are all good
+            return $this->trigger(4, "illegal character '{$matches[0]}'", $matches[0]);
+        }
+    
+        while(1) { // 1 Infinite Loop ;)
+            $op = substr($expr, $index, 1); // get the first character at the current index
+            // find out if we're currently at the beginning of a number/variable/function/parenthesis/operand
+            $ex = preg_match('/^([a-z]\w*\(?|\d+(?:\.\d*)?|\.\d+|\()/', substr($expr, $index), $match);
+            //===============
+            if ($op == '-' and !$expecting_op) { // is it a negation instead of a minus?
+                $stack->push('_'); // put a negation on the stack
+                $index++;
+            } elseif ($op == '_') { // we have to explicitly deny this, because it's legal on the stack 
+                return $this->trigger(4, "illegal character '_'", "_"); // but not in the input expression
+            //===============
+            } elseif ((in_array($op, $ops) or $ex) and $expecting_op) { // are we putting an operator on the stack?
+                if ($ex) { // are we expecting an operator but have a number/variable/function/opening parethesis?
+                    $op = '*'; $index--; // it's an implicit multiplication
+                }
+                // heart of the algorithm:
+                while($stack->count > 0 and ($o2 = $stack->last()) and in_array($o2, $ops) and ($ops_r[$op] ? $ops_p[$op] < $ops_p[$o2] : $ops_p[$op] <= $ops_p[$o2])) {
+                    $output[] = $stack->pop(); // pop stuff off the stack into the output
+                }
+                // many thanks: http://en.wikipedia.org/wiki/Reverse_Polish_notation#The_algorithm_in_detail
+                $stack->push($op); // finally put OUR operator onto the stack
+                $index++;
+                $expecting_op = false;
+            //===============
+            } elseif ($op == ')' and $expecting_op) { // ready to close a parenthesis?
+                while (($o2 = $stack->pop()) != '(') { // pop off the stack back to the last (
+                    if (is_null($o2)) return $this->trigger(5, "unexpected ')'", ")");
+                    else $output[] = $o2;
+                }
+                if (preg_match("/^([a-z]\w*)\($/", $stack->last(2), $matches)) { // did we just close a function?
+                    $fnn = $matches[1]; // get the function name
+                    $arg_count = $stack->pop(); // see how many arguments there were (cleverly stored on the stack, thank you)
+                    $output[] = $stack->pop(); // pop the function and push onto the output
+                    if (in_array($fnn, $this->fb)) { // check the argument count
+                        if($arg_count > 1)
+                            return $this->trigger(6, "wrong number of arguments ($arg_count given, 1 expected)", array($arg_count, 1));
+                    } elseif (array_key_exists($fnn, $this->f)) {
+                        if ($arg_count != count($this->f[$fnn]['args']))
+                            return $this->trigger(6, "wrong number of arguments ($arg_count given, " . count($this->f[$fnn]['args']) . " expected)", array($arg_count, count($this->f[$fnn]['args'])));
+                    } else { // did we somehow push a non-function on the stack? this should never happen
+                        return $this->trigger(7, "internal error");
+                    }
+                }
+                $index++;
+            //===============
+            } elseif ($op == ',' and $expecting_op) { // did we just finish a function argument?
+                while (($o2 = $stack->pop()) != '(') { 
+                    if (is_null($o2)) return $this->trigger(5, "unexpected ','", ","); // oops, never had a (
+                    else $output[] = $o2; // pop the argument expression stuff and push onto the output
+                }
+                // make sure there was a function
+                if (!preg_match("/^([a-z]\w*)\($/", $stack->last(2), $matches))
+                    return $this->trigger(5, "unexpected ','", ",");
+                $stack->push($stack->pop()+1); // increment the argument count
+                $stack->push('('); // put the ( back on, we'll need to pop back to it again
+                $index++;
+                $expecting_op = false;
+            //===============
+            } elseif ($op == '(' and !$expecting_op) {
+                $stack->push('('); // that was easy
+                $index++;
+                $allow_neg = true;
+            //===============
+            } elseif ($ex and !$expecting_op) { // do we now have a function/variable/number?
+                $expecting_op = true;
+                $val = $match[1];
+                if (preg_match("/^([a-z]\w*)\($/", $val, $matches)) { // may be func, or variable w/ implicit multiplication against parentheses...
+                    if (in_array($matches[1], $this->fb) or array_key_exists($matches[1], $this->f)) { // it's a func
+                        $stack->push($val);
+                        $stack->push(1);
+                        $stack->push('(');
+                        $expecting_op = false;
+                    } else { // it's a var w/ implicit multiplication
+                        $val = $matches[1];
+                        $output[] = $val;
+                    }
+                } else { // it's a plain old var or num
+                    $output[] = $val;
+                }
+                $index += strlen($val);
+            //===============
+            } elseif ($op == ')') { // miscellaneous error checking
+                return $this->trigger(5, "unexpected ')'", ")");
+            } elseif (in_array($op, $ops) and !$expecting_op) {
+                return $this->trigger(8, "unexpected operator '$op'", $op);
+            } else { // I don't even want to know what you did to get here
+                return $this->trigger(9, "an unexpected error occured");
+            }
+            if ($index == strlen($expr)) {
+                if (in_array($op, $ops)) { // did we end with an operator? bad.
+                    return $this->trigger(10, "operator '$op' lacks operand", $op);
+                } else {
+                    break;
+                }
+            }
+            while (substr($expr, $index, 1) == ' ') { // step the index past whitespace (pretty much turns whitespace 
+                $index++;                             // into implicit multiplication if no operator is there)
+            }
+        
+        } 
+        while (!is_null($op = $stack->pop())) { // pop everything off the stack and push onto output
+            if ($op == '(') return $this->trigger(11, "expecting ')'", ")"); // if there are (s on the stack, ()s were unbalanced
+            $output[] = $op;
+        }
+        return $output;
+    }
+
+    // evaluate postfix notation
+    function pfx($tokens, $vars = array()) {
+        
+        if ($tokens == false) return false;
+    
+        $stack = new EvalMathStack;
+        
+        foreach ($tokens as $token) { // nice and easy
+            // if the token is a binary operator, pop two values off the stack, do the operation, and push the result back on
+            if (in_array($token, array('+', '-', '*', '/', '^'))) {
+                if (is_null($op2 = $stack->pop())) return $this->trigger(12, "internal error");
+                if (is_null($op1 = $stack->pop())) return $this->trigger(13, "internal error");
+                switch ($token) {
+                    case '+':
+                        $stack->push($op1+$op2); break;
+                    case '-':
+                        $stack->push($op1-$op2); break;
+                    case '*':
+                        $stack->push($op1*$op2); break;
+                    case '/':
+                        if ($op2 == 0) return $this->trigger(14, "division by zero");
+                        $stack->push($op1/$op2); break;
+                    case '^':
+                        $stack->push(pow($op1, $op2)); break;
+                }
+            // if the token is a unary operator, pop one value off the stack, do the operation, and push it back on
+            } elseif ($token == "_") {
+                $stack->push(-1*$stack->pop());
+            // if the token is a function, pop arguments off the stack, hand them to the function, and push the result back on
+            } elseif (preg_match("/^([a-z]\w*)\($/", $token, $matches)) { // it's a function!
+                $fnn = $matches[1];
+                if (in_array($fnn, $this->fb)) { // built-in function:
+                    if (is_null($op1 = $stack->pop())) return $this->trigger(15, "internal error");
+                    $fnn = preg_replace("/^arc/", "a", $fnn); // for the 'arc' trig synonyms
+                    if ($fnn == 'ln') $fnn = 'log';
+                    eval('$stack->push(' . $fnn . '($op1));'); // perfectly safe eval()
+                } elseif (array_key_exists($fnn, $this->f)) { // user function
+                    // get args
+                    $args = array();
+                    for ($i = count($this->f[$fnn]['args'])-1; $i >= 0; $i--) {
+                        if (is_null($args[$this->f[$fnn]['args'][$i]] = $stack->pop())) return $this->trigger(16, "internal error");
+                    }
+                    $stack->push($this->pfx($this->f[$fnn]['func'], $args)); // yay... recursion!!!!
+                }
+            // if the token is a number or variable, push it on the stack
+            } else {
+                if (is_numeric($token)) {
+                    $stack->push($token);
+                } elseif (array_key_exists($token, $this->v)) {
+                    $stack->push($this->v[$token]);
+                } elseif (array_key_exists($token, $vars)) {
+                    $stack->push($vars[$token]);
+                } else {
+                    return $this->trigger(17, "undefined variable '$token'", $token);
+                }
+            }
+        }
+        // when we're out of tokens, the stack should have a single element, the final result
+        if ($stack->count != 1) return $this->trigger(18, "internal error");
+        return $stack->pop();
+    }
+    
+    // trigger an error, but nicely, if need be
+    function trigger($code, $msg, $info = null) {
+        $this->last_error = $msg;
+        $this->last_error_code = array($code, $info);
+        if (!$this->suppress_errors) trigger_error($msg, E_USER_WARNING);
+        return false;
+    }
+}
+
+// for internal use
+class EvalMathStack {
+
+    var $stack = array();
+    var $count = 0;
+    
+    function push($val) {
+        $this->stack[$this->count] = $val;
+        $this->count++;
+    }
+    
+    function pop() {
+        if ($this->count > 0) {
+            $this->count--;
+            return $this->stack[$this->count];
+        }
+        return null;
+    }
+    
+    function last($n=1) {
+        if (isset($this->stack[$this->count-$n])) {
+          return $this->stack[$this->count-$n];
+        }
+        return;
+    }
+}

htdocs/install/mysql/migration/3.7.0-3.8.0.sql

@@ -0,0 +1,29 @@
+--
+-- Be carefull to requests order.
+-- This file must be loaded by calling /install/index.php page
+-- when current version is 3.8.0 or higher.
+--
+-- To rename a table:       ALTER TABLE llx_table RENAME TO llx_table_new;
+-- To add a column:         ALTER TABLE llx_table ADD COLUMN newcol varchar(60) NOT NULL DEFAULT '0' AFTER existingcol;
+-- To rename a column:      ALTER TABLE llx_table CHANGE COLUMN oldname newname varchar(60);
+-- To drop a column:        ALTER TABLE llx_table DROP COLUMN oldname;
+-- To change type of field: ALTER TABLE llx_table MODIFY COLUMN name varchar(60);
+-- To drop a foreign key:   ALTER TABLE llx_table DROP FOREIGN KEY fk_name;
+-- To restrict request to Mysql version x.y use -- VMYSQLx.y
+-- To restrict request to Pgsql version x.y use -- VPGSQLx.y
+-- To make pk to be auto increment (mysql):    VMYSQL4.3 ALTER TABLE llx_c_shipment_mode CHANGE COLUMN rowid rowid INTEGER NOT NULL AUTO_INCREMENT;
+-- To make pk to be auto increment (postgres): VPGSQL8.2 NOT POSSIBLE. MUST DELETE/CREATE TABLE
+-- To set a field as NULL:                     VPGSQL8.2 ALTER TABLE llx_table ALTER COLUMN name DROP NOT NULL;
+-- To set a field as default NULL:             VPGSQL8.2 ALTER TABLE llx_table ALTER COLUMN name SET DEFAULT NULL;
+-- -- VPGSQL8.2 DELETE FROM llx_usergroup_user      WHERE fk_user      NOT IN (SELECT rowid from llx_user);
+-- -- VMYSQL4.1 DELETE FROM llx_usergroup_user      WHERE fk_usergroup NOT IN (SELECT rowid from llx_usergroup);
+
+--create table for price expressions and add column in product supplier
+create table llx_price_expression
+(
+  rowid     integer AUTO_INCREMENT PRIMARY KEY,
+  title     varchar(20) NOT NULL,
+  expression    varchar(80) NOT NULL
+)ENGINE=innodb;
+
+ALTER TABLE llx_product_fournisseur_price ADD fk_price_expression integer DEFAULT NULL;

htdocs/install/mysql/tables/llx_price_expression.sql

@@ -0,0 +1,24 @@
+-- ============================================================================
+-- Copyright (C) 2014		Ion agorria			<ion@agorria.com> 
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program. If not, see <http://www.gnu.org/licenses/>.
+--
+-- ============================================================================
+
+create table llx_price_expression
+(
+	rowid			integer AUTO_INCREMENT PRIMARY KEY,
+	title			varchar(20) NOT NULL,
+	expression		varchar(80) NOT NULL
+)ENGINE=innodb;

htdocs/install/mysql/tables/llx_product_fournisseur_price.sql

@@ -39,5 +39,6 @@ create table llx_product_fournisseur_price
   tva_tx				double(6,3) NOT NULL,
   info_bits				integer NOT NULL DEFAULT 0,
   fk_user				integer,
+  fk_price_expression				integer,
   import_key			varchar(14)                  -- Import key
 )ENGINE=innodb;

htdocs/langs/en_US/admin.lang

@@ -495,6 +495,8 @@ Module1780Name=Categories
 Module1780Desc=Category management (products, suppliers and customers)
 Module2000Name=WYSIWYG editor
 Module2000Desc=Allow to edit some text area using an advanced editor
+Module2200Name=Dynamic Prices
+Module2200Desc=Enable the usage of math expressions for prices
 Module2300Name=Cron
 Module2300Desc=Scheduled task management
 Module2400Name=Agenda

htdocs/langs/en_US/errors.lang

@@ -138,6 +138,24 @@ ErrorMemberNotLinkedToAThirpartyLinkOrCreateFirst=Error, this member is not yet
 ErrorThereIsSomeDeliveries=Error, there is some deliveries linked to this shipment. Deletion refused.
 ErrorCantDeletePaymentReconciliated=Can't delete a payment that had generated a bank transaction that was conciliated
 ErrorCantDeletePaymentSharedWithPayedInvoice=Can't delete a payment shared by at least one invoice with status Payed
+ErrorPriceExpression1=Cannot assign to constant '%s'
+ErrorPriceExpression2=Cannot redefine built-in function '%s'
+ErrorPriceExpression3=Undefined variable '%s' in function definition
+ErrorPriceExpression4=Illegal character '%s'
+ErrorPriceExpression5=Unexpected '%s'
+ErrorPriceExpression6=Wrong number of arguments (%s given, %s expected)
+ErrorPriceExpression8=Unexpected operator '%s'
+ErrorPriceExpression9=An unexpected error occured
+ErrorPriceExpression10=Iperator '%s' lacks operand
+ErrorPriceExpression11=Expecting '%s'
+ErrorPriceExpression14=Division by zero
+ErrorPriceExpression17=Undefined variable '%s'
+ErrorPriceExpression19=Expression not found
+ErrorPriceExpression20=Empty expression
+ErrorPriceExpression21=Empty result '%s'
+ErrorPriceExpression22=Negative result '%s'
+ErrorPriceExpressionInternal=Internal error '%s'
+ErrorPriceExpressionUnknown=Unknown error '%s'
 
 # Warnings
 WarningMandatorySetupNotComplete=Mandatory setup parameters are not yet defined

htdocs/langs/en_US/products.lang

@@ -242,3 +242,8 @@ ForceUpdateChildPriceSoc=Set same price on customer subsidiaries
 PriceByCustomerLog=Price by customer log
 MinimumPriceLimit=Minimum price can't be lower that %s
 MinimumRecommendedPrice=Minimum recommended price is : %s
+PriceExpressionEditor=Price expression editor
+PriceExpressionSelected=Selected price expression
+PriceExpressionEditorHelp="price = 2 + 2" or "2 + 2" for setting the price<br>ExtraFields are variables like "#options_myextrafieldkey# * 2"<br>There are special variables like #quantity# and #tva_tx#<br>Use ; to separate expressions
+PriceMode=Price mode
+PriceNumeric=Number

htdocs/product/class/priceexpression.class.php

@@ -0,0 +1,349 @@
+<?php
+/* Copyright (C) 2007-2012 Laurent Destailleur  <eldy@users.sourceforge.net>
+ * Copyright (C) 2014	   Juanjo Menent		<jmenent@2byte.es>
+/* Copyright (C) 2014      Ion Agorria          <ion@agorria.com> 
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ *	\file       htdocs/product/class/priceexpresion.class.php
+ *	\ingroup    product
+ *  \brief      Class for accesing price expression table
+ */
+
+
+/**
+ *	Class for accesing price expression table
+ */
+class PriceExpression
+{
+	var $db;							//!< To store db handler
+	var $error;							//!< To return error code (or message)
+	var $errors=array();				//!< To return several error codes (or messages)
+    var $id;
+    var $title;
+	var $expression;
+
+    /**
+     *  Constructor
+     *
+     *  @param	DoliDb		$db      Database handler
+     */
+    function __construct($db)
+    {
+        $this->db = $db;
+        return 1;
+    }
+
+
+    /**
+     *  Create object into database
+     *
+     *  @param	User	$user        User that creates
+     *  @param  int		$notrigger   0=launch triggers after, 1=disable triggers
+     *  @return int      		   	 <0 if KO, Id of created object if OK
+     */
+    function create($user, $notrigger=0)
+    {
+		$error=0;
+
+		// Clean parameters        
+		if (isset($this->title)) $this->title=trim($this->title);
+		if (isset($this->expression)) $this->expression=trim($this->expression);
+
+        // Insert request
+		$sql = "INSERT INTO ".MAIN_DB_PREFIX."price_expression (";
+		$sql.= "title, expression";
+		$sql.= ") VALUES (";
+		$sql.= " ".(isset($this->title)?"'".$this->db->escape($this->title)."'":"''").",";
+		$sql.= " ".(isset($this->expression)?"'".$this->db->escape($this->expression)."'":"''");
+		$sql.= ")";
+
+		$this->db->begin();
+
+		dol_syslog(get_class($this)."::create", LOG_DEBUG);
+        $resql=$this->db->query($sql);
+    	if (! $resql) { $error++; $this->errors[]="Error ".$this->db->lasterror(); }
+
+		if (! $error)
+        {
+            $this->id = $this->db->last_insert_id(MAIN_DB_PREFIX.$this->table_element);
+
+			if (! $notrigger)
+			{
+	            // Uncomment this and change MYOBJECT to your own tag if you
+	            // want this action calls a trigger.
+
+	            //// Call triggers
+	            //$result=$this->call_trigger('MYOBJECT_CREATE',$user);
+	            //if ($result < 0) { $error++; //Do also what you must do to rollback action if trigger fail}
+	            //// End call triggers
+			}
+        }
+
+        // Commit or rollback
+        if ($error)
+		{
+			foreach($this->errors as $errmsg)
+			{
+	            dol_syslog(__METHOD__." ".$errmsg, LOG_ERR);
+	            $this->error.=($this->error?', '.$errmsg:$errmsg);
+			}
+			$this->db->rollback();
+			return -1*$error;
+		}
+		else
+		{
+			$this->db->commit();
+            return $this->id;
+		}
+    }
+
+
+    /**
+     *  Load object in memory from the database
+     *
+     *  @param		int		$id    	Id object
+     *  @return		int			    < 0 if KO, 0 if OK but not found, > 0 if OK
+     */
+    function fetch($id)
+    {
+        $sql = "SELECT title, expression";
+        $sql.= " FROM ".MAIN_DB_PREFIX."price_expression";
+        $sql.= " WHERE rowid = ".$id;
+
+    	dol_syslog(get_class($this)."::fetch");
+        $resql=$this->db->query($sql);
+        if ($resql)
+        {
+            $obj = $this->db->fetch_object($resql);
+            if ($obj)
+            {
+                $this->id			= $id;
+                $this->title		= $obj->title;
+				$this->expression	= $obj->expression;
+            	return 1;
+            }
+            else
+            {
+                return 0;
+            }
+        }
+        else
+        {
+      	    $this->error="Error ".$this->db->lasterror();
+            return -1;
+        }
+    }
+
+    /**
+     *    List all price expressions
+     *
+     *    @return	array				Array of price expressions
+     */
+    function list_price_expression()
+    {
+        $sql = "SELECT rowid, title, expression";
+        $sql.= " FROM ".MAIN_DB_PREFIX."price_expression";
+        $sql.= " ORDER BY title";
+
+    	dol_syslog(get_class($this)."::list_price_expression");
+        $resql=$this->db->query($sql);
+        if ($resql)
+        {
+            $retarray = array();
+
+            while ($record = $this->db->fetch_array($resql))
+            {
+                $price_expression_obj = new PriceExpression($this->db);
+                $price_expression_obj->id			= $record["rowid"];
+                $price_expression_obj->title		= $record["title"];
+				$price_expression_obj->expression	= $record["expression"];
+                $retarray[]=$price_expression_obj;
+            }
+
+            $this->db->free($resql);
+            return $retarray;
+        }
+        else
+        {
+            $this->error=$this->db->error();
+            return -1;
+        }
+    }
+
+
+    /**
+     *  Returns any existing rowid with specified title
+     *
+     *  @param		String	$title  Title of expression
+     *  @return		int			    < 0 if KO, 0 if OK but not found, > 0 rowid
+     */
+    function find_title($title)
+    {
+        $sql = "SELECT rowid";
+        $sql.= " FROM ".MAIN_DB_PREFIX."price_expression";
+        $sql.= " WHERE title = '".$this->db->escape($title)."'";
+
+    	dol_syslog(get_class($this)."::find_title");
+        $resql=$this->db->query($sql);
+        if ($resql)
+        {
+            $obj = $this->db->fetch_object($resql);
+            if ($obj)
+            {
+            	return (int) $obj->rowid;
+            }
+            else
+            {
+                return 0;
+            }
+        }
+        else
+        {
+      	    $this->error="Error ".$this->db->lasterror();
+            return -1;
+        }
+    }
+
+
+    /**
+     *  Update object into database
+     *
+     *  @param	User	$user        User that modifies
+     *  @param  int		$notrigger	 0=launch triggers after, 1=disable triggers
+     *  @return int     		   	 <0 if KO, >0 if OK
+     */
+    function update($user=0, $notrigger=0)
+    {
+		$error=0;
+
+		// Clean parameters        
+		if (isset($this->title)) $this->title=trim($this->title);
+		if (isset($this->expression)) $this->expression=trim($this->expression);
+
+        // Update request
+        $sql = "UPDATE ".MAIN_DB_PREFIX."price_expression SET";
+		$sql.= " title = ".(isset($this->title)?"'".$this->db->escape($this->title)."'":"''").",";
+		$sql.= " expression = ".(isset($this->expression)?"'".$this->db->escape($this->expression)."'":"''")."";
+        $sql.= " WHERE rowid = ".$this->id;
+
+		$this->db->begin();
+
+    	dol_syslog(get_class($this)."::update");
+        $resql = $this->db->query($sql);
+    	if (! $resql) { $error++; $this->errors[]="Error ".$this->db->lasterror(); }
+
+		if (! $error)
+		{
+			if (! $notrigger)
+			{
+	            // Uncomment this and change MYOBJECT to your own tag if you
+	            // want this action calls a trigger.
+
+	            //// Call triggers
+	            //$result=$this->call_trigger('MYOBJECT_MODIFY',$user);
+	            //if ($result < 0) { $error++; //Do also what you must do to rollback action if trigger fail}
+	            //// End call triggers
+			 }
+		}
+
+        // Commit or rollback
+		if ($error)
+		{
+			foreach($this->errors as $errmsg)
+			{
+	            dol_syslog(get_class($this)."::update ".$errmsg, LOG_ERR);
+	            $this->error.=($this->error?', '.$errmsg:$errmsg);
+			}
+			$this->db->rollback();
+			return -1*$error;
+		}
+		else
+		{
+			$this->db->commit();
+			return 1;
+		}
+    }
+
+
+ 	/**
+	 *  Delete object in database
+	 *
+     * 	@param	int		$rowid		 Row id of expression
+     *	@param  User	$user        User that deletes
+     *  @param  int		$notrigger	 0=launch triggers after, 1=disable triggers
+	 *  @return	int					 <0 if KO, >0 if OK
+	 */
+	function delete($rowid, $user, $notrigger=0)
+	{
+		$error=0;
+
+		$this->db->begin();
+
+		if (! $error)
+		{
+			if (! $notrigger)
+			{
+				// Uncomment this and change MYOBJECT to your own tag if you
+		        // want this action calls a trigger.
+
+	            //// Call triggers
+	            //$result=$this->call_trigger('MYOBJECT_DELETE',$user);
+	            //if ($result < 0) { $error++; //Do also what you must do to rollback action if trigger fail}
+	            //// End call triggers
+			}
+		}
+
+		if (! $error)
+		{
+    		$sql = "DELETE FROM ".MAIN_DB_PREFIX."price_expression";
+    		$sql.= " WHERE rowid = ".$rowid;
+
+	        dol_syslog(get_class($this)."::delete");
+    		$resql = $this->db->query($sql);
+        	if (! $resql) { $error++; $this->errors[]="Error ".$this->db->lasterror(); }
+		}
+
+        // Commit or rollback
+		if ($error)
+		{
+			foreach($this->errors as $errmsg)
+			{
+	        	dol_syslog(get_class($this)."::delete ".$errmsg, LOG_ERR);
+	            $this->error.=($this->error?', '.$errmsg:$errmsg);
+			}
+			$this->db->rollback();
+			return -1*$error;
+		}
+		else
+		{
+			$this->db->commit();
+			return 1;
+		}
+	}
+
+	/**
+	 *	Initialise object with example values
+	 *	Id must be 0 if object instance is a specimen
+	 *
+	 *	@return	void
+	 */
+	function initAsSpecimen()
+	{
+		$this->id=0;
+		$this->expression='';
+	}
+}

htdocs/product/class/priceparser.class.php

@@ -0,0 +1,240 @@
+<?php
+/* Copyright (C) 2014      Ion Agorria          <ion@agorria.com> 
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ *	\file       htdocs/product/class/priceparser.class.php
+ *	\ingroup    product
+ *	\brief      File of class to calculate prices using expression
+ */
+require_once DOL_DOCUMENT_ROOT.'/includes/evalmath/evalmath.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/class/product.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/class/priceexpression.class.php';
+require_once DOL_DOCUMENT_ROOT.'/core/class/extrafields.class.php';
+
+/**
+ * Class to parse product price expressions
+ */
+class PriceParser
+{
+    protected $db;
+    // Limit of expressions per price
+    public $limit = 100;
+    // The error that ocurred when parsing price
+    public $error;
+    // The expression that caused the error
+    public $error_expr;
+    //The special char
+    public $special_chr = "#";
+    //The separator char
+    public $separator_chr = ";";
+
+	/**
+	 *  Constructor
+	 *
+	 *  @param      DoliDB		$db      Database handler
+	 */
+	function __construct($db)
+	{
+		$this->db = $db;
+	}
+
+	/**
+	 *	Returns translated error
+	 *
+	 *	@return string      Translated error
+	 */
+	public function translated_error()
+	{
+		global $langs;
+		$langs->load("errors");
+		/*
+		-No arg
+		 9, an unexpected error occured
+		14, division by zero
+		19, expression not found
+		20, empty expression
+
+		-1 Arg
+		 1, cannot assign to constant '%s'
+		 2, cannot redefine built-in function '%s'
+		 3, undefined variable '%s' in function definition
+		 4, illegal character '%s'
+		 5, unexpected '%s'
+		 8, unexpected operator '%s'
+		10, operator '%s' lacks operand
+		11, expecting '%s'
+		17, undefined variable '%s'
+		21, empty result '%s'
+		22, negative result '%s'
+
+		-2 Args
+		 6, wrong number of arguments (%s given, %s expected)
+
+		-internal errors
+		 7, internal error
+		12, internal error
+		13, internal error
+		15, internal error
+		16, internal error
+		18, internal error
+		*/
+		if (empty($this->error)) {
+			return $langs->trans("ErrorPriceExpressionUnknown", 0); //this is not supposed to happen
+		} 
+		list($code, $info) = $this->error;
+		if (in_array($code, array(9, 14, 19, 20))) //Errors which have 0 arg
+		{
+			return $langs->trans("ErrorPriceExpression".$code);
+		} 
+		else if (in_array($code, array(1, 2, 3, 4, 5, 8, 10, 11, 17, 21, 22))) //Errors which have 1 arg
+		{
+			return $langs->trans("ErrorPriceExpression".$code, $info);
+		} 
+		else if (in_array($code, array(6))) //Errors which have 2 args
+		{
+			return $langs->trans("ErrorPriceExpression".$code, $info[0], $info[1]);
+		} 
+		else if (in_array($code, array(7, 12, 13, 15, 16, 18))) //Internal errors
+		{
+			return $langs->trans("ErrorPriceExpressionInternal", $code);
+		}
+		else //Unknown errors
+		{
+			return $langs->trans("ErrorPriceExpressionUnknown", $code);
+		}
+	}
+
+	/**
+	 *	Calculates price based on expression
+	 *
+	 *	@param	array  	$values     	Strings to replaces
+	 *	@param	String 	$expression     The expression to parse
+     *  @return int 					> 0 if OK, < 1 if KO
+	 */
+	public function parse_expression($values, $expression)
+	{
+		//Check if empty
+		$expression = trim($expression);
+		if (empty($expression)) 
+		{
+			$this->error = array(20, null);
+			return -1;
+		}
+
+		//Prepare the lib, parameters and values
+		$em = new EvalMath();
+		$em->suppress_errors = true; //Don't print errors on page
+		$this->error_expr = null;
+		$search = array();
+		$replace = array();
+		foreach ($values as $key => $value) {
+			if ($value !== null) {
+				$search[] = $this->special_chr.$key.$this->special_chr;
+				$replace[] = $value;
+			}
+		}
+
+		//Iterate over each expression splitted by $separator_chr
+		$expression = str_replace("\n", $this->separator_chr, $expression);
+		$expressions = explode($this->separator_chr, $expression);
+		$expressions = array_slice($expressions, 0, $limit);
+		foreach ($expressions as $expr) {
+			$expr = trim($expr);
+			if (!empty($expr))
+			{
+				$expr = str_ireplace($search, $replace, $expr);
+				$last_result = $em->evaluate($expr);
+				$this->error = $em->last_error_code;
+				if ($this->error !== null) { //$em->last_error is null if no error happened, so just check if error is not null
+					$this->error_expr = $expr;
+					return -2;
+				}
+			}
+		}
+		$vars = $em->vars();
+		if (empty($vars["price"])) {
+			$vars["price"] = $last_result;
+		}
+		if ($vars["price"] === null) 
+		{
+			$this->error = array(21, $expression);
+			return -3;
+		}
+		if ($vars["price"] < 0) 
+		{
+			$this->error = array(22, $expression);
+			return -4;
+		}
+		return $vars["price"];
+	}
+
+	/**
+	 *	Calculates supplier product price based on product id and string expression
+	 *
+	 *	@param	int					$product     	The Product id to get information
+	 *	@param	string 				$expression     The expression to parse
+	 *	@param	int					$quantity     	Min quantity
+	 *	@param	int					$tva_tx     	VAT rate
+	 *	@param	array 				$extra_values   Any aditional values for expression
+     *  @return int 				> 0 if OK, < 1 if KO
+	 */
+	public function parse_product_supplier_expression($product_id, $expression, $quantity = null, $tva_tx = null, $extra_values = array())
+	{
+		//Accessible values by expressions
+		$expression_values = array(
+			"quantity" => $quantity,
+			"tva_tx" => $tva_tx,
+		);
+		$expression_values = array_merge($expression_values, $extra_values);
+
+		//Retreive all extrafield for product and add it to expression_values
+		$extrafields = new ExtraFields($this->db);
+		$extralabels = $extrafields->fetch_name_optionals_label('product', true);
+		$product = new Product($this->db);
+		$product->fetch_optionals($product_id, $extralabels);
+		foreach($extrafields->attribute_label as $key=>$label)
+		{
+			$expression_values['options_'.$key] = $product->array_options['options_'.$key];
+		}
+
+		//Parse the expression and return the price
+		return $this->parse_expression($expression_values, $expression);
+	}
+
+	/**
+	 *	Calculates supplier product price based on product id and expression id
+	 *
+	 *	@param	int					$product     	The Product id to get information
+	 *	@param	int 				$expression_id  The expression to parse
+	 *	@param	int					$quantity     	Min quantity
+	 *	@param	int					$tva_tx     	VAT rate
+	 *	@param	array 				$extra_values   Any aditional values for expression
+     *  @return int 				> 0 if OK, < 1 if KO
+	 */
+	public function parse_product_supplier($product_id, $expression_id, $quantity = null, $tva_tx = null, $extra_values = array())
+	{
+		$price_expression = new PriceExpression($this->db);
+		$res = $price_expression->fetch($expression_id);
+		if ($res > 1) {
+			$this->error = array(19, null);
+			return -1;
+		}
+
+		//Parse the expression and return the price
+		return $this->parse_product_supplier_expression($product_id, $price_expression->expression, $quantity, $tva_tx, $extra_values);
+	}
+}

htdocs/product/class/product.class.php

@@ -1166,11 +1166,12 @@ class Product extends CommonObject
 	 */
 	function get_buyprice($prodfournprice,$qty,$product_id=0,$fourn_ref=0)
 	{
+		require_once DOL_DOCUMENT_ROOT.'/product/class/priceparser.class.php';
 		$result = 0;
 
 		// We do select by searching with qty and prodfournprice
 		$sql = "SELECT pfp.rowid, pfp.price as price, pfp.quantity as quantity,";
-		$sql.= " pfp.fk_product, pfp.ref_fourn, pfp.fk_soc, pfp.tva_tx";
+		$sql.= " pfp.fk_product, pfp.ref_fourn, pfp.fk_soc, pfp.tva_tx, pfp.fk_price_expression";
 		$sql.= " FROM ".MAIN_DB_PREFIX."product_fournisseur_price as pfp";
 		$sql.= " WHERE pfp.rowid = ".$prodfournprice;
 		if ($qty) $sql.= " AND pfp.quantity <= ".$qty;
@@ -1182,6 +1183,13 @@ class Product extends CommonObject
 			$obj = $this->db->fetch_object($resql);
 			if ($obj && $obj->quantity > 0)		// If found
 			{
+                if (!empty($obj->fk_price_expression)) {
+                    $priceparser = new PriceParser($this->db);
+                    $price_result = $priceparser->parse_product_supplier($obj->fk_product, $obj->fk_price_expression, $obj->quantity, $obj->tva_tx);
+                    if ($price_result >= 0) {
+                    	$obj->price = $price_result;
+                    }
+                }
 				$this->buyprice = $obj->price;                      // \deprecated
 				$this->fourn_pu = $obj->price / $obj->quantity;     // Prix unitaire du produit pour le fournisseur $fourn_id
 				$this->ref_fourn = $obj->ref_fourn;                 // Ref supplier
@@ -1193,7 +1201,7 @@ class Product extends CommonObject
 			{
 				// We do same select again but searching with qty, ref and id product
 				$sql = "SELECT pfp.rowid, pfp.price as price, pfp.quantity as quantity, pfp.fk_soc,";
-				$sql.= " pfp.fk_product, pfp.ref_fourn as ref_supplier, pfp.tva_tx";
+				$sql.= " pfp.fk_product, pfp.ref_fourn as ref_supplier, pfp.tva_tx, pfp.fk_price_expression";
 				$sql.= " FROM ".MAIN_DB_PREFIX."product_fournisseur_price as pfp";
 				$sql.= " WHERE pfp.ref_fourn = '".$fourn_ref."'";
 				$sql.= " AND pfp.fk_product = ".$product_id;
@@ -1208,6 +1216,13 @@ class Product extends CommonObject
 					$obj = $this->db->fetch_object($resql);
 					if ($obj && $obj->quantity > 0)		// If found
 					{
+		                if (!empty($obj->fk_price_expression)) {
+		                    $priceparser = new PriceParser($this->db);
+		                    $price_result = $priceparser->parse_product_supplier($obj->fk_product, $obj->fk_price_expression, $obj->quantity, $obj->tva_tx);
+		                    if ($result >= 0) {
+		                    	$obj->price = $price_result;
+		                    }
+		                }
 						$this->buyprice = $obj->price;                      // deprecated
 						$this->fourn_qty = $obj->quantity;					// min quantity for price
 						$this->fourn_pu = $obj->price / $obj->quantity;     // Prix unitaire du produit pour le fournisseur $fourn_id

htdocs/product/expression.php

@@ -0,0 +1,221 @@
+<?php
+/* Copyright (C) 2014	  Ion Agorria		  <ion@agorria.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ *  \file	   htdocs/product/expression.php
+ *  \ingroup	product
+ *  \brief	  Page for editing expression
+ */
+
+require '../main.inc.php';
+require_once DOL_DOCUMENT_ROOT.'/core/lib/product.lib.php';
+require_once DOL_DOCUMENT_ROOT.'/fourn/class/fournisseur.product.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/class/priceexpression.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/class/priceparser.class.php';
+
+$langs->load("products");
+$langs->load("accountancy"); //"Back" translation is on this file
+
+$id = GETPOST('id', 'int');
+$eid = GETPOST('eid', 'int');
+$action = GETPOST('action', 'alpha'); 
+$title = GETPOST('expression_title', 'alpha');
+$expression = GETPOST('expression');
+$tab = GETPOST('tab', 'alpha');
+$tab = (!empty($tab)) ? $tab : 'card';
+
+// Security check
+$result=restrictedArea($user,'produit|service&fournisseur',$id,'product&product','','','rowid');
+
+//Initialize objects
+$product = new Product($db);
+$product->fetch($id, '');
+
+$price_expression = new PriceExpression($db);
+
+//Fetch expression data
+if (empty($eid)) //This also disables fetch when eid == 0
+{
+	$eid = 0;
+}
+else if ($action != 'delete')
+{
+	$price_expression->fetch($eid);
+}
+
+/*
+ * Actions
+ */
+
+if ($action == 'add')
+{
+	if ($eid == 0)
+	{
+		$result = $price_expression->find_title($title);
+		if ($result == 0) //No existing entry found with title, ok
+		{
+			//Check the expression validity by parsing it
+            $priceparser = new PriceParser($db);
+            $price_result = $priceparser->parse_product_supplier_expression($id, $expression, 0, 0);
+            if ($price_result < 0) { //Expression is not valid
+				setEventMessage($priceparser->translated_error(), 'errors');
+			}
+			else
+			{
+				$price_expression->title = $title;
+				$price_expression->expression = $expression;
+				$result = $price_expression->create($user);	
+				if ($result > 0) //created successfully, set the eid to newly created entry
+				{
+					$eid = $price_expression->id;
+				}
+				else
+				{
+					setEventMessage("add: ".$price_expression->error, 'errors');
+				}
+			}
+		}
+		else if ($result < 0)
+		{
+			setEventMessage("add find: ".$price_expression->error, 'errors');
+		}
+		else
+		{
+			setEventMessage($langs->trans("ErrorRecordAlreadyExists"), 'errors');
+		}
+	}
+}
+
+if ($action == 'update')
+{
+	if ($eid != 0)
+	{
+		$result = $price_expression->find_title($title);
+		if ($result == 0 || $result == $eid) //No existing entry found with title or existing one is the current one, ok
+		{
+			//Check the expression validity by parsing it
+            $priceparser = new PriceParser($db);
+            $price_result = $priceparser->parse_product_supplier_expression($id, $expression, 0, 0);
+            if ($price_result < 0) { //Expression is not valid
+				setEventMessage($priceparser->translated_error(), 'errors');
+			}
+			else
+			{
+				$price_expression->id = $eid;
+				$price_expression->title = $title;
+				$price_expression->expression = $expression;
+				$result = $price_expression->update($user);	
+				if ($result < 0)
+				{
+					setEventMessage("update: ".$price_expression->error, 'errors');
+				}
+			}
+		}
+		else if ($result < 0)
+		{
+			setEventMessage("update find: ".$price_expression->error, 'errors');
+		}
+		else
+		{
+			setEventMessage($langs->trans("ErrorRecordAlreadyExists"), 'errors');
+		}
+	}
+}
+
+if ($action == 'delete')
+{
+	if ($eid != 0)
+	{
+		$result = $price_expression->delete($eid, $user);	
+		if ($result < 0)
+		{
+			setEventMessage("delete: ".$price_expression->error, 'errors');
+		}
+		$eid = 0;
+	}
+}
+
+/*
+ * View
+ */
+
+//Header
+llxHeader("","",$langs->trans("CardProduct".$product->type));
+print_fiche_titre($langs->trans("PriceExpressionEditor"));
+$form = new Form($db);
+
+//Form/Table
+print '<form action="'.$_SERVER['PHP_SELF'].'?id='.$id.'&amp;tab='.$tab.'&amp;eid='.$eid.'" method="POST">';
+print '<input type="hidden" name="token" value="'.$_SESSION['newtoken'].'">';
+print '<input type="hidden" name="action" value='.($eid == 0 ? 'add' : 'update').'>';
+print '<table class="border" width="100%">';
+
+// Price expression selector
+print '<tr><td class="fieldrequired">'.$langs->trans("PriceExpressionSelected").'</td><td>';
+$price_expression_list = array(0 => $langs->trans("New")); //Put the new as first option
+foreach ($price_expression->list_price_expression() as $entry) {
+	$price_expression_list[$entry->id] = $entry->title;
+}
+print $form->selectarray('expression_selection', $price_expression_list, $eid);
+print '</td></tr>';
+
+// Title input
+print '<tr><td class="fieldrequired">'.$langs->trans("Name").'</td><td>';
+print '<input class="flat" name="expression_title" size="15" value="'.($price_expression->title?$price_expression->title:'').'">';
+print '</td></tr>';
+
+//Price expression editor
+print '<tr><td class="fieldrequired">'.$form->textwithpicto($langs->trans("PriceExpressionEditor"),$langs->trans("PriceExpressionEditorHelp"),1).'</td><td>';
+require_once DOL_DOCUMENT_ROOT.'/core/class/doleditor.class.php';
+$doleditor=new DolEditor('expression',isset($price_expression->expression)?$price_expression->expression:'','',300,'','',false,false,false,4,80);
+$doleditor->Create();
+print '</td></tr>';
+print '</table>';
+
+//Buttons
+print '<center>';
+print '<input type="submit" class="butAction" value="'.$langs->trans("Save").'">';
+print '<span id="back" class="butAction">'.$langs->trans("Back").'</span>';
+if ($eid == 0)
+{
+	print '<div class="inline-block divButAction"><span id="action-delete" class="butActionRefused">'.$langs->trans('Delete').'</span></div>'."\n";
+}
+else
+{
+	print '<div class="inline-block divButAction"><a class="butActionDelete" href="'.$_SERVER["PHP_SELF"].'?id='.$id.'&amp;tab='.$tab.'&amp;eid='.$eid.'&amp;action=delete">'.$langs->trans("Delete").'</a></div>';
+}
+print '</center>';
+
+print '</form>';	
+
+// This code reloads the page depending of selected option, goes back in history when back is pressed
+print '<script type="text/javascript">
+	jQuery(document).ready(run);
+	function run() {
+		jQuery("#back").click(on_click);
+		jQuery("#expression_selection").change(on_change);
+	}
+	function on_click() {
+		window.location = "'.str_replace('expression.php', $tab.'.php', $_SERVER["PHP_SELF"]).'?id='.$id.'";
+	}
+	function on_change() {
+		window.location = "'.$_SERVER["PHP_SELF"].'?id='.$id.'&tab='.$tab.'&eid=" + $("#expression_selection").attr("value");
+	}
+</script>';
+
+llxFooter();
+$db->close();

htdocs/product/fournisseurs.php

@@ -5,6 +5,7 @@
  * Copyright (C) 2005-2012 Regis Houssin        <regis.houssin@capnetworks.com>
  * Copyright (C) 2010-2012 Juanjo Menent        <jmenent@2byte.es>
  * Copyright (C) 2012      Christophe Battarel  <christophe.battarel@altairis.fr>
+ * Copyright (C) 2014      Ion Agorria          <ion@agorria.com> 
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -30,6 +31,8 @@ require '../main.inc.php';
 require_once DOL_DOCUMENT_ROOT.'/core/lib/product.lib.php';
 require_once DOL_DOCUMENT_ROOT.'/comm/propal/class/propal.class.php';
 require_once DOL_DOCUMENT_ROOT.'/fourn/class/fournisseur.product.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/class/priceexpression.class.php';
+require_once DOL_DOCUMENT_ROOT.'/product/class/priceparser.class.php';
 
 $langs->load("products");
 $langs->load("suppliers");
@@ -103,6 +106,7 @@ if ($action == 'updateprice' && GETPOST('cancel') <> $langs->trans("Cancel"))
     $npr = preg_match('/\*/', $_POST['tva_tx']) ? 1 : 0 ;
     $tva_tx = str_replace('*','', GETPOST('tva_tx','alpha'));
     $tva_tx = price2num($tva_tx);
+    $price_expression = GETPOST('eid', 'int') == 0 ? 'NULL' : GETPOST('eid', 'int'); //Discard expression if not in expression mode
 
     if ($tva_tx == '')
     {
@@ -126,8 +130,14 @@ if ($action == 'updateprice' && GETPOST('cancel') <> $langs->trans("Cancel"))
 	}
 	if ($_POST["price"] < 0 || $_POST["price"] == '')
 	{
-		$error++;
+		if ($price_expression == 'NULL') { //This is not because of using expression instead of numeric price
-		setEventMessage($langs->trans("ErrorFieldRequired",$langs->transnoentities("Price")), 'errors');
+			$error++;
+			setEventMessage($langs->trans("ErrorFieldRequired",$langs->transnoentities("Price")), 'errors');
+		}
+		else
+		{
+			$_POST["price"] = 0;
+		}
 	}
 
 	$product = new ProductFournisseur($db);
@@ -173,6 +183,26 @@ if ($action == 'updateprice' && GETPOST('cancel') <> $langs->trans("Cancel"))
 			{
 				$error++;
 				setEventMessage($product->error, 'errors');
+			} 
+			else 
+			{
+				if ($price_expression != 'NULL') {
+					//Check the expression validity by parsing it
+	                $priceparser = new PriceParser($db);
+	                $price_result = $priceparser->parse_product_supplier($id, $price_expression, $quantity, $tva_tx);
+	                if ($price_result < 0) { //Expression is not valid
+						$error++;
+						setEventMessage($priceparser->translated_error(), 'errors');
+					}
+				}
+				if (! $error && ! empty($conf->dynamicprices->enabled)) {
+					$ret=$product->set_price_expression($price_expression);
+					if ($ret < 0)
+					{
+						$error++;
+						setEventMessage($product->error, 'errors');
+					}
+				}
 			}
 		}
 
@@ -266,7 +296,7 @@ if ($id || $ref)
 
 				if ($rowid)
 				{
-					$product->fetch_product_fournisseur_price($rowid);
+					$product->fetch_product_fournisseur_price($rowid, 1); //Ignore the math expression when getting the price
 					print_fiche_titre($langs->trans("ChangeSupplierPrice"));
 				}
 				else
@@ -368,8 +398,41 @@ if ($id || $ref)
 				print '<input type="text" class="flat" size="5" name="tva_tx" value="'.(GETPOST("tva_tx")?vatrate(GETPOST("tva_tx")):($default_vat!=''?vatrate($default_vat):'')).'">';
 				print '</td></tr>';
 
+				if (! empty($conf->dynamicprices->enabled)) { //Only show price mode and expression selector if module is enabled
+					// Price mode selector
+					print '<tr><td class="fieldrequired">'.$langs->trans("PriceMode").'</td><td>';
+					$price_expression = new PriceExpression($db);
+					$price_expression_list = array(0 => $langs->trans("PriceNumeric")); //Put the numeric mode as first option
+					foreach ($price_expression->list_price_expression() as $entry) {
+						$price_expression_list[$entry->id] = $entry->title;
+					}
+					$price_expression_preselection = GETPOST('eid') ? GETPOST('eid') : ($product->fk_price_expression ? $product->fk_price_expression : '0');
+					print $form->selectarray('eid', $price_expression_list, $price_expression_preselection);
+					print '&nbsp; <div id="expression_editor" class="button">'.$langs->trans("PriceExpressionEditor").'</div>';
+					print '</td></tr>';
+					// This code hides the numeric price input if is not selected, loads the editor page if editor button is pressed
+					print '<script type="text/javascript">
+						jQuery(document).ready(run);
+						function run() {
+							jQuery("#expression_editor").click(on_click);
+							jQuery("#eid").change(on_change);
+							on_change();
+						}
+						function on_click() {
+							window.location = "'.DOL_URL_ROOT.'/product/expression.php?id='.$id.'&tab=fournisseurs&eid=" + $("#eid").attr("value");
+						}
+						function on_change() {
+							if ($("#eid").attr("value") == 0) {
+								jQuery("#price_numeric").show();
+							} else {
+								jQuery("#price_numeric").hide();
+							}
+						}
+					</script>';
+				}
+
 				// Price qty min
-				print '<tr><td class="fieldrequired">'.$langs->trans("PriceQtyMin").'</td>';
+				print '<tr id="price_numeric"><td class="fieldrequired">'.$langs->trans("PriceQtyMin").'</td>';
 				print '<td><input class="flat" name="price" size="8" value="'.(GETPOST('price')?price(GETPOST('price')):(isset($product->fourn_price)?price($product->fourn_price):'')).'">';
 				print '&nbsp;';
 				print $form->select_PriceBaseType((GETPOST('price_base_type')?GETPOST('price_base_type'):$product->price_base_type), "price_base_type");