[ADD] web_widget_float_formula: improve float field behaviour.

In all the numeric field (float, integer, etc.) the user can tip a formula like in Excel.

web_widget_float_formula/__init__.py

@@ -0,0 +1,4 @@
+# -*- encoding: utf-8 -*-
+################################################################################
+#    See __openerp__.py file for Copyright and Licence Informations.
+################################################################################

web_widget_float_formula/__openerp__.py

@@ -0,0 +1,63 @@
+# -*- encoding: utf-8 -*-
+################################################################################
+#    See Copyright and Licence Informations undermentioned.
+################################################################################
+{
+    'name': 'Web Widget - Formulas in Float fields',
+    'version': '1.0',
+    'category': 'web',
+    'description': """
+Allow to write simple mathematic formulas in Integer / Float fields
+===================================================================
+
+Functionnalities:
+------------------
+    * Possibility to tip a text like "=45 + 4/3 - 5 * (2 +1)";
+    * if the formula is correct, The result will be computed and displayed;
+    * if the formula is not correct, the initial text is displayed;
+
+Documentations:
+------------------
+    * Video: http://www.youtube.com/watch?v=jQGdD34WYrA&hd=1
+
+Technical informations:
+------------------------
+    * Overloads "instance.web.form.FieldFloat"; (so works for fields.integer & fields.float);
+    * To compute, the module simply use the eval() javascript function;
+    * Rounding computation is not done by this module (The module has the same behaviour if the user tips "=1/3" or if he tips "0.33[...]");
+    * avoid code injonction by regexpr test: "=alert('security')" is not valid;
+
+Limits:
+--------
+    * Only supports the four operators: "+" "-" "*" "/" and parenthesis;
+
+Copyright and Licence:
+-----------------------
+    * 2013, Groupement Régional Alimentaire de Proximité (http://www.grap.coop/)
+    * Licence: AGPL-3 (http://www.gnu.org/licenses/)
+
+Contacts :
+----------
+    * Sylvain LE GAL (https://twitter.com/legalsylvain);
+    * <informatique@grap.coop> for any help or question about this module.
+    """,
+    'author': 'GRAP',
+    'website': 'http://www.grap.coop',
+    'license': 'AGPL-3',
+    'depends': [
+        'web',
+        ],
+    'data': [],
+    'demo': [],
+    'js': [
+        'static/src/js/models.js',
+    ],
+    'css': [],
+    'qweb': [],
+    'images': [],
+    'post_load': '',
+    'application': False,
+    'installable': True,
+    'auto_install': False,
+    'images': [],
+}

web_widget_float_formula/static/src/js/models.js

@@ -0,0 +1,132 @@
+/*******************************************************************************
+See __openerp__.py file for Copyright and Licence Informations.
+*******************************************************************************/
+
+openerp.web_widget_float_formula = function (instance) {
+
+    instance.web.FormView = instance.web.FormView.extend({
+        /***********************************************************************
+        Overload section 
+        ***********************************************************************/
+
+        /**
+         * Overload : '_process_save' function 
+            1: to force computation of formula if the user realize a keydown directly after the formula input in a tree view ;
+            2: to clean up the '_formula_text' value in all case to avoid bugs in tree view ;
+         */
+        _process_save: function(save_obj) {
+            for (var f in this.fields) {
+                if (!this.fields.hasOwnProperty(f)) { continue; }
+                f = this.fields[f];
+                if (f.hasOwnProperty('_formula_text')){
+                    currentval = f.$('input').attr('value')
+                    if (typeof currentval != 'undefined'){
+                        formula = f._get_valid_expression(currentval);
+                        if (formula){
+                            f._compute_result();
+                        }
+                    }
+                    f._clean_formula_text();
+                }
+            }
+            return this._super(save_obj);
+        },
+
+    });
+
+    instance.web.form.FieldFloat = instance.web.form.FieldFloat.extend({
+        /***********************************************************************
+        Overload section 
+        ***********************************************************************/
+
+        /**
+         * Overload : 'start' function to catch 'blur' and 'focus' events.
+         */
+        start: function() {
+            this.on("blurred", this, this._compute_result);
+            this.on("focused", this, this._display_formula);
+            return this._super();
+        },
+
+        /**
+         * Overload : 'initialize_content' function to clean '_formula_text' value.
+         */
+        initialize_content: function() {
+            this._clean_formula_text();
+            return this._super();
+        },
+
+        /***********************************************************************
+        Custom section 
+        ***********************************************************************/
+
+        /**
+         * keep in memory the formula to allow user to edit it again.
+         The formula has to be keeped in memory until a 'save' action.
+         */
+        _formula_text: '',
+
+        /**
+         * Clean '_formula_text' value.
+         */
+        _clean_formula_text: function() {
+            this._formula_text = '';
+        },
+
+        /**
+         * Return a valid formula from a val, if possible.
+         Otherwise, return false.
+         */
+        _get_valid_expression: function(val) {
+            // Trim the value
+            currenttxt = val.toString().replace(/^\s+|\s+$/g, '');
+            // Test if the value is a formula
+            if (currenttxt[0] == '=') {
+                // allowed chars : [0-9] .,+-/*() and spaces
+                myreg = RegExp('[0-9]|\\s|\\.|,|\\(|\\)|\\+|\\-|\\*|\\/','g')
+                // Test to avoid code injonction in eval function.
+                if (currenttxt.substring(1).replace(myreg, '') == ''){
+                    try {
+                        // Try to compute
+                        formula = currenttxt.substring(1).replace(/,/g,'.');
+                        var floatval = eval(formula);
+                    }catch (e) {}
+                    if (typeof (floatval) != 'undefined'){
+                        return formula;
+                    }
+                }
+            }
+            return false;
+        },
+
+        /**
+         * test if the content of the field is a valid formula, 
+         * compute the result, and replace the current value by the final result.
+         */
+        _compute_result: function() {
+            var formula
+            // Erase old formula
+            this._formula_text = '';
+            
+            formula = this._get_valid_expression(this.$el.find('input').attr('value'));
+            if (formula){
+                // Store new formula
+                this._formula_text = "=" + formula;
+                // put the result in the field
+                this.set_value(eval(formula));
+                // Force rendering anyway to avoid format loss if no change
+                this.render_value();
+            }
+        },
+
+        /**
+         * Display the stored formula in the field, to allow modification.
+         */
+        _display_formula: function() {
+            if (this._formula_text != ''){
+                this.$el.find('input').val(this._formula_text);
+            }
+        },
+
+    });
+};