[DOC] add more info on xml tag and single file component

closes #401

doc/component.md

@@ -677,7 +677,6 @@ to event `menu-loaded` will receive the payload in its `someMethod` handler
 
 By convention, we use KebabCase for the name of _business_ events.
 
-
 The `t-on` directive allows to prebind some arguments. For example,
 
 ```xml
@@ -695,10 +694,12 @@ One can also directly specify inline statements. For example,
 
 Here, `state` must be defined in the rendering context (typically the component)
 as it will be translated to:
-```js
-button.addEventListener("click", () => { component.state.counter++; });
-```
 
+```js
+button.addEventListener("click", () => {
+  component.state.counter++;
+});
+```
 
 In order to remove the DOM event details from the event handlers (like calls to
 `event.preventDefault`) and let them focus on data logic, _modifiers_ can be

doc/tags.md

@@ -1,8 +1,15 @@
 # 🦉 Tags 🦉
 
+## Content
+
+- [Overview](#overview)
+- [`xml` tag](#xml-tag)
+
+## Overview
+
 Tags are very small helpers to make it easy to write inline templates. There is
 only one currently available tag: `xml`, but we plan to add other tags later,
-such as a `css` tag, which will be used to write single file components.
+such as a `css` tag, which will be used to write [single file components](tooling.md#single-file-component).
 
 ## XML tag
 
@@ -31,8 +38,8 @@ With tags, this process is slightly simplified. The name is uniquely generated,
 and the template is automatically registered:
 
 ```js
-import { Component } from 'owl'
-import { xml } from 'owl/tags'
+const { Component } = owl;
+const { xml } = owl.tags;
 
 class MyComponent extends Component {
     static template = xml`

doc/tooling.md

@@ -60,12 +60,21 @@ useful to compare various performance metrics on some tasks.
 
 ## Single File Component
 
-If you want to have `xml` syntax highlighting while using the `xml` helper which
-helps you define inline templates, there is a VS Code addon `Comment tagged template`
-which, if installed, does exactly that. To enable it, you need to add a comment,
-like this:
+It is very useful to group code by feature instead of by type of file. It makes
+it easier to scale application to larger size.
+
+To do so, Owl currently has a small helper that makes it easy to define a
+template inside a javascript (or typescript) file: the [`xml`](tags.md#xml-tag)
+helper. With this, a template is automatically registered to [QWeb](qweb.md).
+
+This means that the template and the javascript code can be defined in the same
+file. It is not currently possible to add css to the same file, but Owl may
+get a `css` tag helper later.
 
 ```js
+const { Component } = owl;
+const { xml } = owl.tags;
+
 // -----------------------------------------------------------------------------
 // TEMPLATE
 // -----------------------------------------------------------------------------
@@ -85,3 +94,8 @@ class MyComponent extends Component {
   // rest of component...
 }
 ```
+
+Note that the above example has an inline xml comment, just after the `xml` call.
+This is useful for some editor plugins, such as the VS Code addon
+`Comment tagged template`, which, if installed, add syntax highlighting to the
+content of the template string.

src/qweb/extensions.ts

@@ -58,7 +58,9 @@ QWeb.addDirective({
         ctx.addLine(`p${nodeID}.on['${eventName}'] = extra.handlers['${eventName}' + ${nodeID}];`);
       } else {
         const handlerKey = `handler${ctx.generateID()}`;
-        ctx.addLine(`const ${handlerKey} = context['${handlerName}'] && context['${handlerName}'].bind(${params});`);
+        ctx.addLine(
+          `const ${handlerKey} = context['${handlerName}'] && context['${handlerName}'].bind(${params});`
+        );
         handler += `if (${handlerKey}) { ${handlerKey}(e); } else { context.${value}; }`;
         handler += `}`;
         ctx.addLine(`p${nodeID}.on['${eventName}'] = ${handler};`);

tests/component/component.test.ts

@@ -2142,7 +2142,7 @@ describe("other directives with t-component", () => {
           <Child t-on-ev="handler"/>
         </div>`;
       static components = { Child };
-      state = useState({counter: 0});
+      state = useState({ counter: 0 });
       get handler() {
         this.state.counter++;
         return () => {};
@@ -2152,12 +2152,12 @@ describe("other directives with t-component", () => {
     await parent.mount(fixture);
 
     expect(env.qweb.templates[Parent.template].fn.toString()).toMatchSnapshot();
-    expect(fixture.innerHTML).toBe('<div>0<span></span></div>');
+    expect(fixture.innerHTML).toBe("<div>0<span></span></div>");
 
     let child = children(parent)[0];
     child.trigger("ev");
     await nextTick();
-    expect(fixture.innerHTML).toBe('<div>1<span></span></div>');
+    expect(fixture.innerHTML).toBe("<div>1<span></span></div>");
   });
 
   test("t-on with inline statement", async () => {
@@ -2171,18 +2171,18 @@ describe("other directives with t-component", () => {
           <Child t-on-ev="state.counter++"/>
         </div>`;
       static components = { Child };
-      state = useState({counter: 0});
+      state = useState({ counter: 0 });
     }
     const parent = new Parent(env);
     await parent.mount(fixture);
 
     expect(env.qweb.templates[Parent.template].fn.toString()).toMatchSnapshot();
-    expect(fixture.innerHTML).toBe('<div>0<span></span></div>');
+    expect(fixture.innerHTML).toBe("<div>0<span></span></div>");
 
     let child = children(parent)[0];
     child.trigger("ev");
     await nextTick();
-    expect(fixture.innerHTML).toBe('<div>1<span></span></div>');
+    expect(fixture.innerHTML).toBe("<div>1<span></span></div>");
   });
 
   test("t-on with no handler (only modifiers)", async () => {

tests/qweb/qweb.test.ts

@@ -1044,8 +1044,8 @@ describe("t-on", () => {
     qweb.addTemplate("test", `<button t-on-click="state.counter++">Click</button>`);
     let owner = {
       state: {
-        counter: 0,
-      },
+        counter: 0
+      }
     };
     const node = renderToDOM(qweb, "test", owner, { handlers: [] });
     expect(owner.state.counter).toBe(0);
@@ -1058,8 +1058,10 @@ describe("t-on", () => {
     let owner = {
       state: {
         counter: 0,
-        incrementCounter: (inc) => { owner.state.counter += inc; },
-      },
+        incrementCounter: inc => {
+          owner.state.counter += inc;
+        }
+      }
     };
     const node = renderToDOM(qweb, "test", owner, { handlers: [] });
     expect(owner.state.counter).toBe(0);
@@ -1223,7 +1225,7 @@ describe("t-on", () => {
     );
     const node = renderToDOM(qweb, "test", {}, { handlers: [] });
 
-    node.addEventListener('click', (e) => {
+    node.addEventListener("click", e => {
       expect(e.defaultPrevented).toBe(true);
     });