[IMP] component: make template key static

closes #288

src/component/component.ts

@@ -70,12 +70,6 @@ interface Internal<T extends Env, Props> {
   classObj: { [key: string]: boolean } | null;
 }
 
-// If a component does not define explicitely a template
-// key, it needs to find a template with its name (or a parent's).  This is
-// qweb dependant, so we need a place to store this information indexed by
-// qweb instances.
-const TEMPLATE_MAP: { [key: number]: { [name: string]: string } } = {};
-
 //------------------------------------------------------------------------------
 // Component
 //------------------------------------------------------------------------------
@@ -83,7 +77,8 @@ let nextId = 1;
 
 export class Component<T extends Env, Props extends {}, State extends {}> {
   readonly __owl__: Internal<Env, Props>;
-  template?: string;
+  static template?: string | null = null;
+  static _template?: string | null = null;
 
   /**
    * The `el` is the root element of the component.  Note that it could be null:
@@ -527,30 +522,28 @@ export class Component<T extends Env, Props extends {}, State extends {}> {
       return Promise.resolve(h("div"));
     }
     const qweb = this.env.qweb;
-    if (!this.template) {
+    let p = (<any>this).constructor;
-      let tmap = TEMPLATE_MAP[qweb.id];
+    // console.warn(p, p.template, p._template, 'template' in p, p.hasOwnProperty('template'))
-      if (!tmap) {
+    if (!p.hasOwnProperty("_template")) {
-        tmap = {};
+      if (p.template) {
-        TEMPLATE_MAP[qweb.id] = tmap;
+        p._template = p.template;
-      }
-      let p = (<any>this).constructor;
-      let name: string = p.name;
-      let template = tmap[name];
-      if (template) {
-        this.template = template;
       } else {
+        // here, the component and none of its superclasses defines a static `template`
+        // key. So we fall back on looking for a template matching its name (or
+        // one of its subclass).
+
+        let template: string;
         while ((template = p.name) && !(template in qweb.templates) && p !== Component) {
           p = p.__proto__;
         }
         if (p === Component) {
           throw new Error(`Could not find template for component "${this.constructor.name}"`);
         } else {
-          tmap[name] = template;
+          p._template = template;
-          this.template = template;
         }
       }
     }
-    __owl__.render = qweb.render.bind(qweb, this.template);
+    __owl__.render = qweb.render.bind(qweb, p._template);
     this.__observeState();
 
     return this.__render(false, [], scope, vars);

src/qweb/qweb.ts

@@ -125,8 +125,6 @@ function parseXML(xml: string): Document {
   return doc;
 }
 
-let nextID = 1;
-
 //------------------------------------------------------------------------------
 // QWeb rendering engine
 //------------------------------------------------------------------------------
@@ -147,10 +145,6 @@ export class QWeb extends EventBus {
   // dev mode enables better error messages or more costly validations
   static dev: boolean = false;
 
-  // the id field is useful to be able to hash qweb instances.  The current
-  // use case is that component's templates are qweb dependant, and need to be
-  // able to map a qweb instance to a template name.
-  id = nextID++;
 
   // slots contains sub templates defined with t-set inside t-component nodes, and
   // are meant to be used by the t-slot directive.
@@ -326,8 +320,8 @@ export class QWeb extends EventBus {
   _compile(name: string, elem: Element, parentContext?: Context): CompiledTemplate {
     const isDebug = elem.attributes.hasOwnProperty("t-debug");
     const ctx = new Context(name);
-    if (elem.tagName !== 't') {
+    if (elem.tagName !== "t") {
-        ctx.shouldDefineResult = false;
+      ctx.shouldDefineResult = false;
     }
     if (parentContext) {
       ctx.templates = Object.create(parentContext.templates);

src/router/Link.ts

@@ -12,7 +12,7 @@ export const LINK_TEMPLATE = `
 type Props = Destination;
 
 export class Link<Env extends RouterEnv> extends Component<Env, Props, {}> {
-  template = LINK_TEMPLATE_NAME;
+  static template = LINK_TEMPLATE_NAME;
   href: string = this.env.router.destToPath(this.props);
 
   async willUpdateProps(nextProps) {

src/router/RouteComponent.ts

@@ -9,7 +9,7 @@ export const ROUTE_COMPONENT_TEMPLATE = `
     </t>`;
 
 export class RouteComponent extends Component<any, {}, {}> {
-  template = ROUTE_COMPONENT_TEMPLATE_NAME;
+  static template = ROUTE_COMPONENT_TEMPLATE_NAME;
   routes: any[] = [];
   constructor(parent, props) {
     super(parent, props);

tests/component/component.test.ts

@@ -1288,7 +1288,7 @@ describe("composition", () => {
         </div>`
     );
     class Parent extends Widget {
-      template = "parent";
+      static template = "parent";
       state = {
         numbers: [1, 2, 3]
       };
@@ -3003,7 +3003,7 @@ describe("can deduce template from name", () => {
 
   test("can find template of parent component, defined by template key", async () => {
     class ABC extends Widget {
-      template = "Achel";
+      static template = "Achel";
     }
     class DEF extends ABC {}
     env.qweb.addTemplate("Achel", "<span>Orval</span>");