[DOC] add some information on variables and t-call

closes #540

doc/reference/qweb_templating_language.md

@@ -500,6 +500,15 @@ will result in :
 </div>
 ```
 
+This can be used to define variables scoped to a sub template:
+
+```xml
+<t t-call="other-template">
+    <t t-set="var" t-value="1"/>
+</t>
+<!-- "var" does not exist here -->
+```
+
 ### Translations
 
 By default, QWeb specify that templates should be translated. If this behaviour

src/misc/portal.ts

@@ -137,8 +137,7 @@ export class Portal extends Component<any, any> {
     }
     this.__checkVNodeStructure(vnode);
     const shouldDeploy =
-      (!this.portal || this.el!.contains(this.portal.elm!)) &&
-      !this.doTargetLookUp;
+      (!this.portal || this.el!.contains(this.portal.elm!)) && !this.doTargetLookUp;
 
     if (!this.doTargetLookUp && !shouldDeploy) {
       // Only on pure patching, provided the

src/qweb/qweb.ts

@@ -650,7 +650,7 @@ export class QWeb extends EventBus {
       if (!name.startsWith("t-") && !(<Element>node).getAttribute("t-attf-" + name)) {
         const attID = ctx.generateID();
         if (name === "class") {
-          if (value = value.trim()) {
+          if ((value = value.trim())) {
             let classDef = value
               .split(/\s+/)
               .map(a => `'${a}':true`)

tests/misc/portal.test.ts

@@ -563,16 +563,16 @@ describe("Portal: Basic use and DOM placement", () => {
     const parent = new Parent();
     await parent.mount(fixture);
 
-    expect(outside.innerHTML).toBe('<span>gloria</span>');
-    expect(parent.el!.innerHTML).toBe('<portal></portal>');
+    expect(outside.innerHTML).toBe("<span>gloria</span>");
+    expect(parent.el!.innerHTML).toBe("<portal></portal>");
 
     parent.unmount();
-    expect(outside.innerHTML).toBe('');
-    expect(parent.el!.innerHTML).toBe('<portal><span>gloria</span></portal>');
+    expect(outside.innerHTML).toBe("");
+    expect(parent.el!.innerHTML).toBe("<portal><span>gloria</span></portal>");
 
     await parent.mount(fixture);
-    expect(outside.innerHTML).toBe('<span>gloria</span>');
-    expect(parent.el!.innerHTML).toBe('<portal></portal>');
+    expect(outside.innerHTML).toBe("<span>gloria</span>");
+    expect(parent.el!.innerHTML).toBe("<portal></portal>");
   });
 
   test("portal manual unmount with subcomponent", async () => {
@@ -587,7 +587,7 @@ describe("Portal: Basic use and DOM placement", () => {
       }
     }
     class Parent extends Component<any, any> {
-      static components = { Portal , Child };
+      static components = { Portal, Child };
       static template = xml`
         <div>
           <Portal target="'#outside'">
@@ -599,16 +599,16 @@ describe("Portal: Basic use and DOM placement", () => {
     const parent = new Parent();
     await parent.mount(fixture);
 
-    expect(outside.innerHTML).toBe('<span>gloria</span>');
-    expect(parent.el!.innerHTML).toBe('<portal></portal>');
+    expect(outside.innerHTML).toBe("<span>gloria</span>");
+    expect(parent.el!.innerHTML).toBe("<portal></portal>");
 
     parent.unmount();
-    expect(outside.innerHTML).toBe('');
-    expect(parent.el!.innerHTML).toBe('<portal><span>gloria</span></portal>');
+    expect(outside.innerHTML).toBe("");
+    expect(parent.el!.innerHTML).toBe("<portal><span>gloria</span></portal>");
 
     await parent.mount(fixture);
-    expect(outside.innerHTML).toBe('<span>gloria</span>');
-    expect(parent.el!.innerHTML).toBe('<portal></portal>');
+    expect(outside.innerHTML).toBe("<span>gloria</span>");
+    expect(parent.el!.innerHTML).toBe("<portal></portal>");
   });
 });