[IMP] qweb: add registerTemplate method

doc/qweb.md

@@ -129,6 +129,15 @@ It's API is quite simple:
   const str = qweb.renderToString("someTemplate", somecontext);
   ```
 
+- **`registerTemplate(name, template)`**: static function to register an global
+  QWeb template. This is useful for commonly used components accross the
+  application, and for making a template available to an application without
+  having a reference to the actual QWeb instance.
+
+  ```js
+  QWeb.registerTemplate('mytemplate', `<div>some template`);
+  ```
+
 - **`register(name, Component)`**: static function to register an OWL Component
   to QWeb's global registry. Globally registered Components can be used in
   templates (see the `t-component` directive). This is useful for commonly used

src/qweb/qweb.ts

@@ -129,7 +129,7 @@ function parseXML(xml: string): Document {
 // QWeb rendering engine
 //------------------------------------------------------------------------------
 export class QWeb extends EventBus {
-  templates: { [name: string]: Template } = {};
+  templates: { [name: string]: Template };
   static utils = UTILS;
   static components = Object.create(null);
 
@@ -141,6 +141,8 @@ export class QWeb extends EventBus {
   };
   static DIRECTIVES: Directive[] = [];
 
+  static TEMPLATES: { [name: string]: Template } = {};
+
   h = h;
   // dev mode enables better error messages or more costly validations
   static dev: boolean = false;
@@ -160,6 +162,7 @@ export class QWeb extends EventBus {
 
   constructor(data?: string) {
     super();
+    this.templates = Object.create(QWeb.TEMPLATES);
     if (data) {
       this.addTemplates(data);
     }
@@ -184,6 +187,20 @@ export class QWeb extends EventBus {
     QWeb.components[name] = Component;
   }
 
+  /**
+   * Register globally a template.  All QWeb instances will obtain their
+   * templates from their own template map, and then, from the global static
+   * TEMPLATES property.
+   */
+  static registerTemplate(name: string, template: string) {
+    if (QWeb.TEMPLATES[name]) {
+      throw new Error(`Template '${name}' has already been registered`);
+    }
+    const qweb = new QWeb();
+    qweb.addTemplate(name, template);
+    QWeb.TEMPLATES[name] = qweb.templates[name];
+  }
+
   /**
    * Add a template to the internal template map.  Note that it is not
    * immediately compiled.

tests/qweb/qweb.test.ts

@@ -11,6 +11,7 @@ import { normalize, renderToDOM, renderToString, trim, nextTick } from "../helpe
 let qweb: QWeb;
 
 beforeEach(() => {
+  QWeb.TEMPLATES = {};
   qweb = new QWeb();
 });
 
@@ -1278,3 +1279,22 @@ describe("update on event bus", () => {
     expect(fn).toBeCalledTimes(1);
   });
 });
+
+describe("global template registration", () => {
+  test("can register template globally", () => {
+    expect.assertions(5);
+    let qweb = new QWeb();
+    try {
+      qweb.render("mytemplate");
+    } catch (e) {
+      expect(e.message).toMatch("Template mytemplate does not exist");
+    }
+    expect(qweb.templates.mytemplate).toBeUndefined();
+
+    QWeb.registerTemplate("mytemplate", "<div>global</div>");
+    expect(qweb.templates.mytemplate).toBeDefined();
+    const vnode = qweb.render("mytemplate");
+    expect(vnode.sel).toBe("div");
+    expect((vnode as any).children[0].text).toBe("global");
+  });
+});

tests/router/RouteComponent.test.ts

@@ -53,7 +53,6 @@ describe("RouteComponent", () => {
     await nextTick();
     expect(fixture.innerHTML).toBe("<div><span>Users</span></div>");
     expect(env.qweb.templates[ROUTE_COMPONENT_TEMPLATE_NAME].fn.toString()).toMatchSnapshot();
-
   });
 
   test("can render parameterized route", async () => {