[IMP] qweb/components: remove t-ref on components

Refs to component expose a lot of implementation details that should be
private to parents. Parent to child communication should go through
props.

src/qweb/compiler.ts

@@ -261,8 +261,7 @@ export class QWebCompiler {
     return block;
   }
 
-  insertBlock(expression: string, block: BlockDescription, ctx: Context): string | null {
-    let id: string | null = null;
+  insertBlock(expression: string, block: BlockDescription, ctx: Context): void {
     let blockExpr = block.generateExpr(expression);
     const tKeyExpr = ctx.tKeyExpr;
     if (block.parentVar) {
@@ -271,7 +270,7 @@ export class QWebCompiler {
         keyArg = `${tKeyExpr} + ${keyArg}`;
       }
       this.addLine(`${block.parentVar}[${ctx.index}] = withKey(${blockExpr}, ${keyArg});`);
-      return id;
+      return;
     }
 
     if (tKeyExpr) {
@@ -283,7 +282,6 @@ export class QWebCompiler {
     } else {
       this.addLine(`let ${block.varName} = ${blockExpr};`);
     }
-    return id;
   }
 
   generateCode(): string {

src/qweb/parser.ts

@@ -302,11 +302,8 @@ function parseDOMNode(node: Element, ctx: ParsingContext): AST | null {
   if (tagName === "pre") {
     ctx = { inPreTag: true };
   }
-  let ref = null;
-  if (node.hasAttribute("t-ref")) {
-    ref = node.getAttribute("t-ref");
-    node.removeAttribute("t-ref");
-  }
+  const ref = node.getAttribute("t-ref");
+  node.removeAttribute("t-ref");
 
   for (let child of node.childNodes) {
     const ast = parseNode(child, ctx);