[IMP] qweb: add global Component registry to qweb

Closes #112

src/qweb_core.ts

@@ -132,6 +132,7 @@ let nextID = 1;
 export class QWeb {
   templates: { [name: string]: Template } = {};
   utils = UTILS;
+  static widgets = Object.create(null);
 
   // dev mode enables better error messages or more costly validations
   static dev: boolean = false;
@@ -157,6 +158,13 @@ export class QWeb {
     }
   }
 
+  static register(name: string, Component: any) {
+    if (QWeb.widgets[name]) {
+      throw new Error(`Component '${name}' has already been registered`);
+    }
+    QWeb.widgets[name] = Component;
+  }
+
   /**
    * Add a template to the internal template map.  Note that it is not
    * immediately compiled.
@@ -269,6 +277,9 @@ export class QWeb {
       // pollute the rendering context by adding some keys in it.
       ctx.code.unshift("    let owner = context;");
     }
+    if (ctx.shouldDefineQWeb) {
+      ctx.code.unshift("    let QWeb = this.constructor;");
+    }
     if (ctx.shouldDefineUtils) {
       ctx.code.unshift("    let utils = this.utils;");
     }
@@ -616,6 +627,7 @@ export class Context {
   rootContext: Context;
   caller: Element | undefined;
   shouldDefineOwner: boolean = false;
+  shouldDefineQWeb: boolean = false;
   shouldDefineUtils: boolean = false;
   shouldProtectContext: boolean = false;
   inLoop: boolean = false;

src/qweb_extensions.ts

@@ -343,6 +343,7 @@ QWeb.addDirective({
   atNodeEncounter({ ctx, value, node }): boolean {
     ctx.addLine("//WIDGET");
     ctx.rootContext.shouldDefineOwner = true;
+    ctx.rootContext.shouldDefineQWeb = true;
     ctx.rootContext.shouldDefineUtils = true;
     let props = node.getAttribute("t-props");
     let keepAlive = node.getAttribute("t-keepalive") ? true : false;
@@ -458,7 +459,9 @@ QWeb.addDirective({
 
     ctx.addIf(`!w${widgetID}`);
     // new widget
-    ctx.addLine(`let W${widgetID} = context.widgets['${value}'];`);
+    ctx.addLine(
+      `let W${widgetID} = context.widgets && context.widgets['${value}'] || QWeb.widgets['${value}'];`
+    );
 
     // maybe only do this in dev mode...
     ctx.addLine(