[IMP] portal: add support for .closest modifier

It is sometimes useful in practice to be able to configure the portal so
that it looks for a target as close as possible as the portal location.
For example, in odoo, a portal may be set up in a form view that should
target the current form view. But if the form view itself is in a
dialog, it may fail, because it may find a valid target in the form view that is located
underneath.

With this commit, we add a .closest modifier to the `t-portal`
directive.

doc/reference/portal.md

@@ -15,3 +15,11 @@ class SomeComponent extends Component {
 The `t-portal` directive takes a valid css selector as argument. The content of
 the portalled template will be mounted at the corresponding location. Note that
 Owl need to insert an empty text node at the location of the portalled content.
+
+The `t-portal` directive supports a `.closest` modifier. It is useful to select
+the closest target from the portal location: Owl will look for a target in the
+current parent element, then in its parent, and so on until it finds it.
+
+```xml
+      <div t-portal.closest="'.target'">some content</div>
+```

src/compiler/code_generator.ts

@@ -1371,7 +1371,9 @@ export class CodeGenerator {
     });
 
     const target = compileExpr(ast.target);
-    const blockString = `${id}({target: ${target},slots: {'default': {__render: ${name}.bind(this), __ctx: ${ctxStr}}}}, key + \`${key}\`, node, ctx, Portal)`;
+    const blockString = `${id}({target: ${target},${
+      ast.isClosest ? "isClosest: true," : ""
+    }slots: {'default': {__render: ${name}.bind(this), __ctx: ${ctxStr}}}}, key + \`${key}\`, node, ctx, Portal)`;
     if (block) {
       this.insertAnchor(block);
     }

src/compiler/parser.ts

@@ -169,6 +169,7 @@ export interface ASTTranslation {
 export interface ASTTPortal {
   type: ASTType.TPortal;
   target: string;
+  isClosest: boolean;
   content: AST;
 }
 
@@ -833,11 +834,18 @@ function parseTTranslation(node: Element, ctx: ParsingContext): AST | null {
 // -----------------------------------------------------------------------------
 
 function parseTPortal(node: Element, ctx: ParsingContext): AST | null {
-  if (!node.hasAttribute("t-portal")) {
+  let target, isClosest;
+  if (node.hasAttribute("t-portal")) {
+    target = node.getAttribute("t-portal")!;
+    node.removeAttribute("t-portal");
+    isClosest = false;
+  } else if (node.hasAttribute("t-portal.closest")) {
+    target = node.getAttribute("t-portal.closest")!;
+    node.removeAttribute("t-portal.closest");
+    isClosest = true;
+  } else {
     return null;
   }
-  const target = node.getAttribute("t-portal")!;
-  node.removeAttribute("t-portal");
   const content = parseNode(node, ctx);
   if (!content) {
     return {
@@ -848,6 +856,7 @@ function parseTPortal(node: Element, ctx: ParsingContext): AST | null {
   return {
     type: ASTType.TPortal,
     target,
+    isClosest,
     content,
   };
 }

src/runtime/portal.ts

@@ -5,20 +5,34 @@ import { OwlError } from "./error_handling";
 
 const VText: any = text("").constructor;
 
+function getTarget(
+  currentParentEl: HTMLElement | Document,
+  selector: string,
+  isClosest: boolean
+): HTMLElement | null {
+  if (!isClosest || currentParentEl === document) {
+    return document.querySelector(selector);
+  }
+  const attempt = currentParentEl.querySelector(selector) as HTMLElement | null;
+  return attempt || getTarget(currentParentEl.parentElement!, selector, true);
+}
+
 class VPortal extends VText implements Partial<VNode<VPortal>> {
   content: BDom | null;
   selector: string;
+  isClosest: boolean;
   target: HTMLElement | null = null;
 
-  constructor(selector: string, content: BDom) {
+  constructor(selector: string, isClosest: boolean, content: BDom) {
     super("");
     this.selector = selector;
+    this.isClosest = isClosest;
     this.content = content;
   }
 
   mount(parent: HTMLElement, anchor: ChildNode) {
     super.mount(parent, anchor);
-    this.target = document.querySelector(this.selector) as any;
+    this.target = getTarget(parent, this.selector, this.isClosest);
     if (this.target) {
       this.content!.mount(this.target!, null);
     } else {
@@ -54,16 +68,19 @@ class VPortal extends VText implements Partial<VNode<VPortal>> {
 export function portalTemplate(app: any, bdom: any, helpers: any) {
   let { callSlot } = helpers;
   return function template(ctx: any, node: any, key = ""): any {
-    return new VPortal(ctx.props.target, callSlot(ctx, node, key, "default", false, null));
+    return new VPortal(
+      ctx.props.target,
+      ctx.props.isClosest,
+      callSlot(ctx, node, key, "default", false, null)
+    );
   };
 }
 
 export class Portal extends Component {
   static template = "__portal__";
   static props = {
-    target: {
-      type: String,
-    },
+    target: String,
+    isClosest: { type: Boolean, optional: true },
     slots: true,
   };
 
@@ -73,7 +90,7 @@ export class Portal extends Component {
     onMounted(() => {
       const portal: VPortal = node.bdom;
       if (!portal.target) {
-        const target: HTMLElement = document.querySelector(this.props.target);
+        const target = getTarget(portal.parentEl, this.props.target, this.props.isClosest);
         if (target) {
           portal.content!.moveBeforeDOMNode(target.firstChild, target);
         } else {

tests/compiler/parser.test.ts

@@ -1998,6 +1998,7 @@ describe("qweb parser", () => {
   test("t-portal", async () => {
     expect(parse(`<t t-portal="target">Content</t>`)).toEqual({
       type: ASTType.TPortal,
+      isClosest: false,
       target: "target",
       content: { type: ASTType.Text, value: "Content" },
     });
@@ -2008,6 +2009,7 @@ describe("qweb parser", () => {
       condition: "condition",
       content: {
         content: { type: ASTType.Text, value: "Content" },
+        isClosest: false,
         target: "target",
         type: ASTType.TPortal,
       },
@@ -2016,4 +2018,13 @@ describe("qweb parser", () => {
       type: ASTType.TIf,
     });
   });
+
+  test("t-portal with .closest", async () => {
+    expect(parse(`<t t-portal.closest="target">Content</t>`)).toEqual({
+      type: ASTType.TPortal,
+      isClosest: true,
+      target: "target",
+      content: { type: ASTType.Text, value: "Content" },
+    });
+  });
 });

tests/misc/__snapshots__/portal.test.ts.snap

@@ -999,3 +999,26 @@ exports[`Portal: UI/UX focus is kept across re-renders 2`] = `
   }
 }"
 `;
+
+exports[`portal .closest suffix basic use of .suffix 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  const Portal = app.Portal;
+  const comp1 = app.createComponent(null, false, true, false, false);
+
+  let block2 = createBlock(\`<p class=\\"target\\">far target</p>\`);
+  let block3 = createBlock(\`<div><p class=\\"target\\">close target</p><block-child-0/></div>\`);
+
+  function slot1(ctx, node, key = \\"\\") {
+    return text(\`portal content\`);
+  }
+
+  return function template(ctx, node, key = \\"\\") {
+    const b2 = block2();
+    const b5 = comp1({target: '.target',isClosest: true,slots: {'default': {__render: slot1.bind(this), __ctx: ctx}}}, key + \`__1\`, node, ctx, Portal);
+    const b3 = block3([], [b5]);
+    return multi([b2, b3]);
+  }
+}"
+`;

tests/misc/portal.test.ts

@@ -1028,3 +1028,21 @@ describe("Portal: Props validation", () => {
     expect(error!.message).toBe(`invalid portal target`);
   });
 });
+
+describe("portal .closest suffix", () => {
+  test("basic use of .suffix", async () => {
+    class Parent extends Component {
+      static template = xml`
+        <p class="target">far target</p>
+        <div>
+          <p class="target">close target</p>
+          <t t-portal.closest="'.target'">portal content</t>
+        </div>`;
+    }
+
+    await mount(Parent, fixture);
+    expect(fixture.innerHTML).toBe(
+      '<p class="target">far target</p><div><p class="target">close targetportal content</p></div>'
+    );
+  });
+});