[REVERT] web: form_relational_widget: remove unused javascript code

This reverts commit 6c0376e932.
It turns out that this javascript code was not unused after all.
(see kanban view inside customers, clicking on them should open the
contact in a popup)

addons/web/static/src/js/views/form_relational_widgets.js

@@ -1136,6 +1136,24 @@ var One2ManyList = AddAnItemList.extend({
     },
 });
 
+var One2ManyFormView = FormView.extend({
+    form_template: 'One2Many.formview',
+    load_form: function(data) {
+        this._super(data);
+        var self = this;
+        this.$buttons.find('button.oe_form_button_create').click(function() {
+            self.save().done(self.on_button_new);
+        });
+    },
+    do_notify_change: function() {
+        if (this.dataset.parent_view) {
+            this.dataset.parent_view.do_notify_change();
+        } else {
+            this._super.apply(this, arguments);
+        }
+    }
+});
+
 var One2ManyViewManager = ViewManager.extend({
     init: function(parent, dataset, views, flags) {
         // By default, render buttons and pager in O2M fields, but no sidebar
@@ -1150,7 +1168,8 @@ var One2ManyViewManager = ViewManager.extend({
         this.set_cp_bus(this.control_panel.get_bus());
         this._super(parent, dataset, views, flags);
         this.registry = core.view_registry.extend({
-            'list': One2ManyListView
+            list: One2ManyListView,
+            form: One2ManyFormView,
         });
         this.__ignore_blur = false;
     },
@@ -1158,6 +1177,36 @@ var One2ManyViewManager = ViewManager.extend({
         this.control_panel.prependTo(this.$el);
         return this._super();
     },
+    switch_mode: function(mode, unused) {
+        if (mode !== 'form') {
+            return this._super(mode, unused);
+        }
+        var self = this;
+        var id = self.o2m.dataset.index !== null ? self.o2m.dataset.ids[self.o2m.dataset.index] : null;
+        var pop = new common.FormOpenPopup(this);
+        pop.show_element(self.o2m.field.relation, id, self.o2m.build_context(), {
+            title: _t("Open: ") + self.o2m.string,
+            create_function: function(data, options) {
+                return self.o2m.data_create(data, options);
+            },
+            write_function: function(id, data, options) {
+                return self.o2m.data_update(id, data, {}).done(function() {
+                    self.o2m.reload_current_view();
+                });
+            },
+            alternative_form_view: self.o2m.field.views ? self.o2m.field.views.form : undefined,
+            parent_view: self.o2m.view,
+            child_name: self.o2m.name,
+            read_function: function(ids, fields, options) {
+                return self.o2m.data_read(ids, fields, options);
+            },
+            form_view_options: {'not_interactible_on_create':true},
+            readonly: self.o2m.get("effective_readonly")
+        });
+        pop.on("elements_selected", self, function() {
+            self.o2m.reload_current_view();
+        });
+    },
 });
 
 var FieldMany2ManyTags = AbstractManyField.extend(common.CompletionFieldMixin, common.ReinitializeFieldMixin, {

addons/web/static/src/xml/base.xml

@@ -1573,6 +1573,11 @@
     </a>
 </t>
 
+<t t-name="One2Many.formview" t-extend="FormView">
+    <t t-jquery=".oe_form_buttons" t-operation="inner">
+        <button type="button" class="oe_button oe_form_button_create">Add</button>
+    </t>
+</t>
 <t t-name="One2Many.listview" t-extend="ListView">
     <t t-jquery="thead > tr:first">
         this.removeAttr('t-if');