[IMP] parser: add support for custom directives

This commit adds the support for custom directives. To use the
custom directive, an Object of functions needs to be configured on
the owl APP:
```js
 new App(..., {
    customDirectives: {
     test_directive: function (el, value) {
            el.setAttribute("t-on-click", value);
            return el;
       }
   }
  });
```
The functions will be called when a custom directive with the name of the
function is found. The original element will be replaced with the one
returned by the function.
This :
```xml
<div t-custom-test_directive="click" />
```
will be replace by :
```xml
<div t-on-click="value"/>
```

issue : https://github.com/odoo/owl/issues/1650

doc/reference/app.md

@@ -66,6 +66,8 @@ The `config` object is an object with some of the following keys:
   needs a template. If undefined is returned, owl looks into the app templates.
 - **`warnIfNoStaticProps (boolean, default=false)`**: if true, Owl will log a warning
   whenever it encounters a component that does not provide a [static props description](props.md#props-validation).
+- **`customDirectives (object)`**: if given, the corresponding function on the object will be called
+  on the template custom directives: `t-custom-*` (see [Custom Directives](templates.md#custom-directives)).
 
 ## `mount` helper
 

doc/reference/templates.md

@@ -18,6 +18,7 @@
   - [Sub Templates](#sub-templates)
   - [Dynamic Sub Templates](#dynamic-sub-templates)
   - [Debugging](#debugging)
+  - [Custom Directives](#custom-directives)
 - [Fragments](#fragments)
 - [Inline templates](#inline-templates)
 - [Rendering svg](#rendering-svg)
@@ -80,6 +81,7 @@ needs. Here is a list of all Owl specific directives:
 | `t-slot`, `t-set-slot`, `t-slot-scope` | [Rendering a slot](slots.md)                                    |
 | `t-model`                              | [Form input bindings](input_bindings.md)                        |
 | `t-tag`                                | [Rendering nodes with dynamic tag name](#dynamic-tag-names)     |
+| `t-custom-*`                           | [Rendering nodes with custom directives](#custom-directives)    |
 
 ## QWeb Template Reference
 
@@ -588,6 +590,35 @@ will stop execution if the browser dev tools are open.
 
 will print 42 to the console.
 
+### Custom Directives
+
+Owl 2 supports the declaration of custom directives. To use them, an Object of functions needs to be configured on the owl APP:
+
+```js
+ new App(..., {
+    customDirectives: {
+     test_directive: function (el, value) {
+            el.setAttribute("t-on-click", value);
+       }
+   }
+  });
+```
+
+The functions will be called when a custom directive with the name of the
+function is found. The original element will be replaced with the one
+modified by the function.
+This :
+
+```xml
+<div t-custom-test_directive="click" />
+```
+
+will be replaced by :
+
+```xml
+<div t-on-click="value"/>
+```
+
 ## Fragments
 
 Owl 2 supports templates with an arbitrary number of root elements, or even just

src/common/types.ts

@@ -0,0 +1,4 @@
+export type customDirectives = Record<
+  string,
+  (node: Element, value: string, modifier?: string) => void
+>;

src/compiler/index.ts

@@ -1,3 +1,4 @@
+import type { customDirectives } from "../common/types";
 import type { TemplateSet } from "../runtime/template_set";
 import type { BDom } from "../runtime/blockdom";
 import { CodeGenerator, Config } from "./code_generator";
@@ -10,13 +11,14 @@ export type TemplateFunction = (app: TemplateSet, bdom: any, helpers: any) => Te
 
 interface CompileOptions extends Config {
   name?: string;
+  customDirectives?: customDirectives;
 }
 export function compile(
   template: string | Element,
   options: CompileOptions = {}
 ): TemplateFunction {
   // parsing
-  const ast = parse(template);
+  const ast = parse(template, options.customDirectives);
 
   // some work
   const hasSafeContext =

src/compiler/parser.ts

@@ -1,4 +1,5 @@
 import { OwlError } from "../common/owl_error";
+import type { customDirectives } from "../common/types";
 import { parseXML } from "../common/utils";
 
 // -----------------------------------------------------------------------------
@@ -198,23 +199,26 @@ export type AST =
 // -----------------------------------------------------------------------------
 const cache: WeakMap<Element, AST> = new WeakMap();
 
-export function parse(xml: string | Element): AST {
+export function parse(xml: string | Element, customDir?: customDirectives): AST {
+  const ctx = {
+    inPreTag: false,
+    customDirectives: customDir,
+  };
   if (typeof xml === "string") {
     const elem = parseXML(`<t>${xml}</t>`).firstChild as Element;
-    return _parse(elem);
+    return _parse(elem, ctx);
   }
   let ast = cache.get(xml);
   if (!ast) {
     // we clone here the xml to prevent modifying it in place
-    ast = _parse(xml.cloneNode(true) as Element);
+    ast = _parse(xml.cloneNode(true) as Element, ctx);
     cache.set(xml, ast);
   }
   return ast;
 }
 
-function _parse(xml: Element): AST {
+function _parse(xml: Element, ctx: ParsingContext): AST {
   normalizeXML(xml);
-  const ctx = { inPreTag: false };
   return parseNode(xml, ctx) || { type: ASTType.Text, value: "" };
 }
 
@@ -222,6 +226,7 @@ interface ParsingContext {
   tModelInfo?: TModelInfo | null;
   nameSpace?: string;
   inPreTag: boolean;
+  customDirectives?: customDirectives;
 }
 
 function parseNode(node: Node, ctx: ParsingContext): AST | null {
@@ -229,6 +234,7 @@ function parseNode(node: Node, ctx: ParsingContext): AST | null {
     return parseTextCommentNode(node, ctx);
   }
   return (
+    parseTCustom(node, ctx) ||
     parseTDebugLog(node, ctx) ||
     parseTForEach(node, ctx) ||
     parseTIf(node, ctx) ||
@@ -277,6 +283,37 @@ function parseTextCommentNode(node: Node, ctx: ParsingContext): AST | null {
   return null;
 }
 
+function parseTCustom(node: Element, ctx: ParsingContext): AST | null {
+  if (!ctx.customDirectives) {
+    return null;
+  }
+  const nodeAttrsNames = node.getAttributeNames();
+  for (let attr of nodeAttrsNames) {
+    if (attr === "t-custom" || attr === "t-custom-") {
+      throw new OwlError("Missing custom directive name with t-custom directive");
+    }
+    if (attr.startsWith("t-custom-")) {
+      const directiveName = attr.split(".")[0].slice(9);
+      const customDirective = ctx.customDirectives[directiveName];
+      if (!customDirective) {
+        throw new OwlError(`Custom directive "${directiveName}" is not defined`);
+      }
+      const value = node.getAttribute(attr)!;
+      const modifier = attr.split(".").length > 1 ? attr.split(".")[1] : undefined;
+      node.removeAttribute(attr);
+      try {
+        customDirective(node, value, modifier);
+      } catch (error) {
+        throw new OwlError(
+          `Custom directive "${directiveName}" throw the following error: ${error}`
+        );
+      }
+      return parseNode(node, ctx);
+    }
+  }
+  return null;
+}
+
 // -----------------------------------------------------------------------------
 // debugging
 // -----------------------------------------------------------------------------

src/index.ts

@@ -12,5 +12,6 @@ TemplateSet.prototype._compileTemplate = function _compileTemplate(
     dev: this.dev,
     translateFn: this.translateFn,
     translatableAttributes: this.translatableAttributes,
+    customDirectives: this.customDirectives,
   });
 };

src/runtime/template_set.ts

@@ -5,6 +5,7 @@ import { Portal, portalTemplate } from "./portal";
 import { helpers } from "./template_helpers";
 import { OwlError } from "../common/owl_error";
 import { parseXML } from "../common/utils";
+import type { customDirectives } from "../common/types";
 
 const bdom = { text, createBlock, list, multi, html, toggler, comment };
 
@@ -14,6 +15,7 @@ export interface TemplateSetConfig {
   translateFn?: (s: string) => string;
   templates?: string | Document | Record<string, string>;
   getTemplate?: (s: string) => Element | Function | string | void;
+  customDirectives?: customDirectives;
 }
 
 export class TemplateSet {
@@ -27,6 +29,7 @@ export class TemplateSet {
   translateFn?: (s: string) => string;
   translatableAttributes?: string[];
   Portal = Portal;
+  customDirectives: customDirectives;
 
   constructor(config: TemplateSetConfig = {}) {
     this.dev = config.dev || false;
@@ -42,6 +45,7 @@ export class TemplateSet {
       }
     }
     this.getRawTemplate = config.getTemplate;
+    this.customDirectives = config.customDirectives || {};
   }
 
   addTemplate(name: string, template: string | Element) {

tests/compiler/__snapshots__/t_custom.test.ts.snap

@@ -0,0 +1,29 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`t-custom can use t-custom directive on a node 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div class=\\"my-div\\" block-handler-0=\\"click\\"/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let hdlr1 = [ctx['click'], ctx];
+    return block1([hdlr1]);
+  }
+}"
+`;
+
+exports[`t-custom can use t-custom directive with modifier on a node 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div class=\\"my-div\\" block-handler-0=\\"click\\"/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let hdlr1 = [ctx['click'], ctx];
+    return block1([hdlr1]);
+  }
+}"
+`;

tests/compiler/t_custom.test.ts

@@ -0,0 +1,55 @@
+import { App, Component, xml } from "../../src";
+import { makeTestFixture, snapshotEverything } from "../helpers";
+
+let fixture: HTMLElement;
+
+snapshotEverything();
+
+beforeEach(() => {
+  fixture = makeTestFixture();
+});
+
+describe("t-custom", () => {
+  test("can use t-custom directive on a node", async () => {
+    const steps: string[] = [];
+    class SomeComponent extends Component {
+      static template = xml`<div t-custom-plop="click" class="my-div"/>`;
+      click() {
+        steps.push("clicked");
+      }
+    }
+    const app = new App(SomeComponent, {
+      customDirectives: {
+        plop: (node, value) => {
+          node.setAttribute("t-on-click", value);
+        },
+      },
+    });
+    await app.mount(fixture);
+    expect(fixture.innerHTML).toBe(`<div class="my-div"></div>`);
+    fixture.querySelector("div")!.click();
+    expect(steps).toEqual(["clicked"]);
+  });
+
+  test("can use t-custom directive with modifier on a node", async () => {
+    const steps: string[] = [];
+    class SomeComponent extends Component {
+      static template = xml`<div t-custom-plop.mouse="click" class="my-div"/>`;
+      click() {
+        steps.push("clicked");
+      }
+    }
+    const app = new App(SomeComponent, {
+      customDirectives: {
+        plop: (node, value, modifier) => {
+          node.setAttribute("t-on-click", value);
+          steps.push(modifier || "");
+        },
+      },
+    });
+    await app.mount(fixture);
+    expect(fixture.innerHTML).toBe(`<div class="my-div"></div>`);
+    fixture.querySelector("div")!.click();
+    expect(steps).toEqual(["mouse", "clicked"]);
+  });
+});