[FIX] web: monetary field was adding DOM at each rendering

Before this commit, the `render` method of the monetary field added
the <input/> and currency elements without removing the previous
ones. As this was called on each related `onchange`, the DOM was
growing at each of these changes.

addons/web/static/src/js/fields/basic_fields.js

@@ -144,22 +144,27 @@ var InputField = DebouncedField.extend({
      * Formats an input element for edit mode. This is in a separate function so
      * extending widgets can use it on their input without having input as tagName.
      *
-     * @param {jQueryElement} $input
      * @private
+     * @param {jQuery|undefined} $input
+     *        The <input/> element to prepare and save as the $input attribute.
+     *        If no element is given, the <input/> is created.
+     * @returns {jQuery} the prepared this.$input element
      */
     _prepareInput: function ($input) {
-        $input.addClass('o_form_input');
-        $input.attr('type', 'text');
-        if (this.attrs.placeholder) {
-            $input.attr('placeholder', this.attrs.placeholder);
-        }
-        $input.attr('id', this.idForLabel);
-        // save cursor position to restore it after updating value
+        this.$input = $input || $("<input/>");
+        this.$input.addClass('o_form_input');
+        this.$input.attr({
+            type: 'text',
+            id: this.idForLabel,
+            placeholder: this.attrs.placeholder || "",
+        });
+        // Save cursor position to restore it after updating value
         var selectionStart = this.$input[0].selectionStart;
         var selectionEnd = this.$input[0].selectionEnd;
         this.$input.val(this._formatValue(this.value));
         this.$input[0].selectionStart = selectionStart;
         this.$input[0].selectionEnd = selectionEnd;
+        return this.$input;
     },
     /**
      * Formats the HTML input tag for edit mode and stores selection status.
@@ -170,8 +175,7 @@ var InputField = DebouncedField.extend({
     _renderEdit: function () {
         // Keep a reference to the input so $el can become something else
         // without losing track of the actual input.
-        this.$input = this.$el;
-        this._prepareInput(this.$input);
+        this._prepareInput(this.$el);
     },
     /**
      * Resets the content to the formated value in readonly mode.
@@ -368,20 +372,21 @@ var FieldMonetary = InputField.extend({
      * @private
      */
     _renderEdit: function () {
-        if (this.nodeOptions.currency_id) {
-            var currency = session.get_currency(this.nodeOptions.currency_id);
-            var $currencySymbol = $('<span>').text(currency.symbol);
-            this.$input = $('<input>');
-            this._prepareInput(this.$input);
-            this.$input.appendTo(this.$el);
-            if (currency.position === "after") {
-                this.$el.append($currencySymbol);
-            } else {
-                this.$el.prepend($currencySymbol);
-            }
-        }
-        else {
+        if (!this.nodeOptions.currency_id) {
             this._super.apply(this, arguments);
+            return;
+        }
+
+        this.$el.empty();
+        // Prepare and add the input
+        this._prepareInput().appendTo(this.$el);
+        // prepare and add the currency symbol
+        var currency = session.get_currency(this.nodeOptions.currency_id);
+        var $currencySymbol = $('<span>', {text: currency.symbol});
+        if (currency.position === "after") {
+            this.$el.append($currencySymbol);
+        } else {
+            this.$el.prepend($currencySymbol);
         }
     },
 

addons/web/static/test/fields/basic_fields_tests.js

@@ -1332,12 +1332,17 @@ QUnit.module('basic_fields', {
         list.destroy();
     });
 
-
     QUnit.test('monetary field with real monetary field in model', function (assert) {
-        assert.expect(2);
+        assert.expect(3);
 
         this.data.partner.fields.qux.type = "monetary";
 
+        this.data.partner.onchanges = {
+            bar: function (obj) {
+                obj.qux = obj.bar ? 100 : obj.qux;
+            },
+        };
+
         var form = createView({
             View: FormView,
             model: 'partner',
@@ -1346,6 +1351,7 @@ QUnit.module('basic_fields', {
                     '<sheet>' +
                         '<field name="qux"/>' +
                         '<field name="currency_id" invisible="1"/>' +
+                        '<field name="bar"/>' +
                     '</sheet>' +
                 '</form>',
             res_id: 5,
@@ -1362,6 +1368,10 @@ QUnit.module('basic_fields', {
         assert.strictEqual(form.$('.o_form_field_monetary > input').val(), "9.10",
             "input value in edition should only contain the value, without the currency");
 
+        form.$('input[type="checkbox"]').click(); // Change the field on which the monetary depends
+        assert.strictEqual(form.$('.o_form_field_monetary > input').length, 1,
+            "After the onchange, the monetary <input/> should not have been duplicated");
+
         form.destroy();
     });