[NEW] New module: attachment_attach_non_editable

In odoo, by default, you can't add attachments to a record if the form view
is set as not editable (``edit='false'`` in the form tag)

This module adds a new form view attribute, ``attach=``, which lets you
enable attachment uploads even in non-editable forms.

attachment_attach_non_editable/static/src/js/sidebar.js

@@ -0,0 +1,19 @@
+odoo.define('attachment_attach_non_editable.sidebar', function(require) {
+    "use strict";
+
+    var core = require('web.core');
+    var Sidebar = require('web.Sidebar');
+
+
+    Sidebar.include({
+
+        init: function(parent, options) {
+            this._super.apply(this, arguments);
+            if (parent.is_action_enabled('attach')) {
+                this.options.attachable = true;
+            }
+        }
+
+    });
+
+});

attachment_attach_non_editable/static/src/xml/sidebar.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<templates id="template" xml:space="preserve">
+
+  <t t-extend="Sidebar">
+    <t t-jquery=".o_sidebar_add_attachment">
+      this.attr('t-if', "section.name == 'files' and (widget.options.editable or widget.options.attachable)");
+    </t>
+  </t>
+
+</templates>