Integrate with ElementInternals

Closes [#1023][] Replace the requirement for an `<input type="hidden">` element with direct `<form>` integration through built-in support for [ElementInternals][]. According to the [Form-associated custom elements][] section of [More capable form controls][], various behaviors that the `<trix-editor>` element was recreating are provided out of the box. For example, the `<input type="hidden">`-`[input]` attribute pairing can be achieved through [ElementInternals.setFormValue][]. Similarly, the `<label>` element support can be achieved through [ElementInternals.labels][]. [#1023]: #1023 [ElementInternals]: https://developer.mozilla.org/en-US/docs/Web/API/ElementInternals [Form-associated custom elements]: https://web.dev/articles/more-capable-form-controls#form-associated_custom_elements [More capable form controls]: https://web.dev/articles/more-capable-form-controls [ElementInternals.setFormValue]: https://developer.mozilla.org/en-US/docs/Web/API/ElementInternals/setFormValue [ElementInternals.labels]: https://developer.mozilla.org/en-US/docs/Web/API/ElementInternals/labels
basecamp · Jan 16, 2024 · e1ad3a8 · e1ad3a8
1 parent 06d8b1d
commit e1ad3a8
Show file tree

Hide file tree

Showing 11 changed files with 77 additions and 118 deletions.
diff --git a/README.md b/README.md
@@ -55,16 +55,27 @@ Like an HTML `<textarea>`, `<trix-editor>` accepts `autofocus` and `placeholder`
 
 ## Integrating With Forms
 
-To submit the contents of a `<trix-editor>` with a form, first define a hidden input field in the form and assign it an `id`. Then reference that `id` in the editor’s `input` attribute.
+To label a `<trix-editor>` element, render the element with an `[id]` attribute, then render a `<label>` element with a `[for]` attribute that corresponds to the `[id]`:
+
+```html
+<label for="editor">Editor</label>
+<trix-editor id="editor"></trix-editor>
+```
+
+To submit the contents of a `<trix-editor>` with a `<form>`, render the element with a `[name]` attribute and its initial value as its inner HTML.
 
 ```html
 <form …>
-  <input id="x" type="hidden" name="content">
-  <trix-editor input="x"></trix-editor>
+  <trix-editor name="content"></trix-editor>
 </form>
 ```
 
-Trix will automatically update the value of the hidden input field with each change to the editor.
+To associate the element with a `<form>` that isn't an ancestor, render the element with a `[form]` attribute that references the `<form>` element by its `[id]`:
+
+```html
+<form id="a-form-element" …></form>
+<trix-editor name="content" form="a-form-element"></trix-editor>
+```
 
 ## Populating With Stored Content
 

diff --git a/assets/index.html b/assets/index.html
@@ -41,6 +41,11 @@
         Trix.Inspector.install(event.target);
       });
 
+      document.addEventListener("trix-change", function(event) {
+        var input = document.getElementById("input")
+        input.value = event.target.value
+      })
+
       document.addEventListener("trix-attachment-add", function(event) {
         var attachment = event.attachment;
         if (attachment.file) {
@@ -72,7 +77,8 @@
   </head>
   <body>
     <main>
-      <trix-editor autofocus class="trix-content" input="input"></trix-editor>
+      <label for="editor">Input</label>
+      <trix-editor autofocus id="editor" class="trix-content"></trix-editor>
       <details id="output">
         <summary>Output</summary>
         <textarea readonly id="input"></textarea>

diff --git a/src/test/system/custom_element_test.js b/src/test/system/custom_element_test.js
@@ -442,16 +442,24 @@ testGroup("Custom element API", { template: "editor_empty" }, () => {
 
   test("editor resets to its original value on form reset", async () => {
     const element = getEditorElement()
-    const { form } = element.inputElement
+    const { form } = element
 
     await typeCharacters("hello")
     form.reset()
     expectDocument("\n")
   })
 
+  test("editor sanitizes initial value", async () => {
+    const element = getEditorElement()
+
+    expectDocument("\n")
+
+    assert.equal(element.innerHTML, "")
+  })
+
   test("editor resets to last-set value on form reset", async () => {
     const element = getEditorElement()
-    const { form } = element.inputElement
+    const { form } = element
 
     element.value = "hi"
     await typeCharacters("hello")
@@ -461,7 +469,7 @@ testGroup("Custom element API", { template: "editor_empty" }, () => {
 
   test("editor respects preventDefault on form reset", async () => {
     const element = getEditorElement()
-    const { form } = element.inputElement
+    const { form } = element
     const preventDefault = (event) => event.preventDefault()
 
     await typeCharacters("hello")
@@ -475,25 +483,12 @@ testGroup("Custom element API", { template: "editor_empty" }, () => {
 
 testGroup("<label> support", { template: "editor_with_labels" }, () => {
   test("associates all label elements", () => {
-    const labels = [ document.getElementById("label-1"), document.getElementById("label-3") ]
-    assert.deepEqual(getEditorElement().labels, labels)
-  })
-
-  test("focuses when <label> clicked", () => {
-    document.getElementById("label-1").click()
-    assert.equal(getEditorElement(), document.activeElement)
-  })
-
-  test("focuses when <label> descendant clicked", () => {
-    document.getElementById("label-1").querySelector("span").click()
-    assert.equal(getEditorElement(), document.activeElement)
-  })
+    const element = getEditorElement()
+    const labels = Array.from(element.labels)
+    const controls = labels.map((label) => label.control)
 
-  test("does not focus when <label> controls another element", () => {
-    const label = document.getElementById("label-2")
-    assert.notEqual(getEditorElement(), label.control)
-    label.click()
-    assert.notEqual(getEditorElement(), document.activeElement)
+    assert.deepEqual(labels, [ document.getElementById("label-1"), document.getElementById("label-3") ])
+    assert.deepEqual(controls, [ element, element ])
   })
 })
 
@@ -505,8 +500,8 @@ testGroup("form property references its <form>", { template: "editors_with_forms
   })
 
   test("transitively accesses its related <input> element's <form>", () => {
-    const form = document.getElementById("input-form")
-    const editor = document.getElementById("editor-with-input-form")
+    const form = document.getElementById("attribute-form")
+    const editor = document.getElementById("editor-with-attribute-form")
     assert.equal(editor.form, form)
   })
 

diff --git a/src/test/system/installation_process_test.js b/src/test/system/installation_process_test.js
@@ -21,28 +21,21 @@ testGroup("Installation process", { template: "editor_html" }, () => {
 })
 
 testGroup("Installation process without specified elements", { template: "editor_empty" }, () =>
-  test("creates identified toolbar and input elements", () => {
+  test("creates identified toolbar", () => {
     const editorElement = getEditorElement()
 
     const toolbarId = editorElement.getAttribute("toolbar")
     assert.ok(/trix-toolbar-\d+/.test(toolbarId), `toolbar id not assert.ok ${JSON.stringify(toolbarId)}`)
     const toolbarElement = document.getElementById(toolbarId)
     assert.ok(toolbarElement, "toolbar element not assert.ok")
     assert.equal(editorElement.toolbarElement, toolbarElement)
-
-    const inputId = editorElement.getAttribute("input")
-    assert.ok(/trix-input-\d+/.test(inputId), `input id not assert.ok ${JSON.stringify(inputId)}`)
-    const inputElement = document.getElementById(inputId)
-    assert.ok(inputElement, "input element not assert.ok")
-    assert.equal(editorElement.inputElement, inputElement)
   })
 )
 
 testGroup("Installation process with specified elements", { template: "editor_with_toolbar_and_input" }, () => {
   test("uses specified elements", () => {
     const editorElement = getEditorElement()
     assert.equal(editorElement.toolbarElement, document.getElementById("my_toolbar"))
-    assert.equal(editorElement.inputElement, document.getElementById("my_input"))
     assert.equal(editorElement.value, "<div>Hello world</div>")
   })
 
@@ -58,7 +51,6 @@ testGroup("Installation process with specified elements", { template: "editor_wi
 
     const editorElement = getEditorElement()
     assert.equal(editorElement.toolbarElement, document.getElementById("my_toolbar"))
-    assert.equal(editorElement.inputElement, document.getElementById("my_input"))
     assert.equal(editorElement.value, "<div>Hello world</div>")
   })
 })
diff --git a/src/test/test_helpers/fixtures/editor_html.js b/src/test/test_helpers/fixtures/editor_html.js
@@ -1,3 +1,3 @@
 export default () =>
-  `<input id="my_input" type="hidden" value="&lt;div&gt;Hello world&lt;/div&gt;">
-  <trix-editor input="my_input" autofocus placeholder="Say hello..."></trix-editor>`
+  `<trix-editor input="my_input" autofocus placeholder="Say hello..."><div>Hello world</div></trix-editor>
+  `
diff --git a/src/test/test_helpers/fixtures/editor_unsafe.js b/src/test/test_helpers/fixtures/editor_unsafe.js
@@ -0,0 +1,2 @@
+export default () => `<trix-editor autofocus><script>alert("unsafe")</script></trix-editor>
+`
diff --git a/src/test/test_helpers/fixtures/editor_with_image.js b/src/test/test_helpers/fixtures/editor_with_image.js
@@ -1,5 +1,4 @@
 import { TEST_IMAGE_URL } from "./test_image_url"
 
 export default () =>
-  `<trix-editor input="my_input" autofocus placeholder="Say hello..."></trix-editor>
-  <input id="my_input" type="hidden" value="ab&lt;img src=&quot;${TEST_IMAGE_URL}&quot; width=&quot;10&quot; height=&quot;10&quot;&gt;">`
+  `<trix-editor autofocus placeholder="Say hello...">ab<img src="${TEST_IMAGE_URL}" width="10" height="10"></trix-editor>`
diff --git a/src/test/test_helpers/fixtures/editor_with_toolbar_and_input.js b/src/test/test_helpers/fixtures/editor_with_toolbar_and_input.js
@@ -1,6 +1,5 @@
 export default () =>
   `<ul id="my_editor">
     <li><trix-toolbar id="my_toolbar"></trix-toolbar></li>
-    <li><trix-editor toolbar="my_toolbar" input="my_input" autofocus placeholder="Say hello..."></trix-editor></li>
-    <li><input id="my_input" type="hidden" value="&lt;div&gt;Hello world&lt;/div&gt;"></li>
+    <li><trix-editor toolbar="my_toolbar" autofocus placeholder="Say hello..."><div>Hello world</div></trix-editor></li>
   </ul>`
diff --git a/src/test/test_helpers/fixtures/editors_with_forms.js b/src/test/test_helpers/fixtures/editors_with_forms.js
@@ -3,9 +3,7 @@ export default () =>
     <trix-editor id="editor-with-ancestor-form"></trix-editor>
   </form>
 
-  <form id="input-form">
-    <input type="hidden" id="hidden-input">
-  </form>
-  <trix-editor id="editor-with-input-form" input="hidden-input"></trix-editor>
+  <form id="attribute-form"></form>
+  <trix-editor id="editor-with-attribute-form" form="attribute-form"></trix-editor>
 
   <trix-editor id="editor-with-no-form"></trix-editor>`
diff --git a/src/trix/controllers/editor_controller.js b/src/trix/controllers/editor_controller.js
@@ -503,7 +503,7 @@ export default class EditorController extends Controller {
   updateInputElement() {
     const element = this.compositionController.getSerializableElement()
     const value = serializeToContentType(element, "text/html")
-    return this.editorElement.setInputElementValue(value)
+    return this.editorElement.setFormValue(value)
   }
 
   notifyEditorElement(message, data) {

diff --git a/src/trix/elements/trix_editor_element.js b/src/trix/elements/trix_editor_element.js
@@ -1,7 +1,6 @@
 import * as config from "trix/config"
 
 import {
-  findClosestElementFromNode,
   handleEvent,
   handleEventOnce,
   installDefaultCSSForTagName,
@@ -161,6 +160,15 @@ installDefaultCSSForTagName("trix-editor", `\
 }`)
 
 export default class TrixEditorElement extends HTMLElement {
+  static formAssociated = true
+
+  #internals
+  #value
+
+  constructor() {
+    super()
+    this.#internals = this.attachInternals()
+  }
 
   // Properties
 
@@ -174,19 +182,7 @@ export default class TrixEditorElement extends HTMLElement {
   }
 
   get labels() {
-    const labels = []
-    if (this.id && this.ownerDocument) {
-      labels.push(...Array.from(this.ownerDocument.querySelectorAll(`label[for='${this.id}']`) || []))
-    }
-
-    const label = findClosestElementFromNode(this, { matchingSelector: "label" })
-    if (label) {
-      if ([ this, null ].includes(label.control)) {
-        labels.push(label)
-      }
-    }
-
-    return labels
+    return this.#internals.labels
   }
 
   get toolbarElement() {
@@ -204,33 +200,23 @@ export default class TrixEditorElement extends HTMLElement {
   }
 
   get form() {
-    return this.inputElement?.form
-  }
-
-  get inputElement() {
-    if (this.hasAttribute("input")) {
-      return this.ownerDocument?.getElementById(this.getAttribute("input"))
-    } else if (this.parentNode) {
-      const inputId = `trix-input-${this.trixId}`
-      this.setAttribute("input", inputId)
-      const element = makeElement("input", { type: "hidden", id: inputId })
-      this.parentNode.insertBefore(element, this.nextElementSibling)
-      return element
-    } else {
-      return undefined
-    }
+    return this.#internals.form
   }
 
   get editor() {
     return this.editorController?.editor
   }
 
+  get type() {
+    return this.localName
+  }
+
   get name() {
-    return this.inputElement?.name
+    return this.getAttribute("name")
   }
 
   get value() {
-    return this.inputElement?.value
+    return this.#value
   }
 
   set value(defaultValue) {
@@ -246,10 +232,9 @@ export default class TrixEditorElement extends HTMLElement {
     }
   }
 
-  setInputElementValue(value) {
-    if (this.inputElement) {
-      this.inputElement.value = value
-    }
+  setFormValue(value) {
+    this.#value = value
+    this.#internals.setFormValue(value)
   }
 
   // Element lifecycle
@@ -264,62 +249,34 @@ export default class TrixEditorElement extends HTMLElement {
         triggerEvent("trix-before-initialize", { onElement: this })
         this.editorController = new EditorController({
           editorElement: this,
-          html: this.defaultValue = this.value,
+          html: this.defaultValue = this.innerHTML,
         })
         requestAnimationFrame(() => triggerEvent("trix-initialize", { onElement: this }))
       }
       this.editorController.registerSelectionManager()
-      this.registerResetListener()
-      this.registerClickListener()
       autofocus(this)
     }
   }
 
   disconnectedCallback() {
     this.editorController?.unregisterSelectionManager()
-    this.unregisterResetListener()
-    return this.unregisterClickListener()
   }
 
-  // Form support
+  // ElementInternals lifecycle
 
-  registerResetListener() {
-    this.resetListener = this.resetBubbled.bind(this)
-    return window.addEventListener("reset", this.resetListener, false)
-  }
+  formAssociatedCallback(form) {
 
-  unregisterResetListener() {
-    return window.removeEventListener("reset", this.resetListener, false)
   }
 
-  registerClickListener() {
-    this.clickListener = this.clickBubbled.bind(this)
-    return window.addEventListener("click", this.clickListener, false)
-  }
+  formDisabledCallback(disabled) {
 
-  unregisterClickListener() {
-    return window.removeEventListener("click", this.clickListener, false)
   }
 
-  resetBubbled(event) {
-    if (event.defaultPrevented) return
-    if (event.target !== this.form) return
-    return this.reset()
+  formResetCallback() {
+    this.value = this.defaultValue
   }
 
-  clickBubbled(event) {
-    if (event.defaultPrevented) return
-    if (this.contains(event.target)) return
-
-    const label = findClosestElementFromNode(event.target, { matchingSelector: "label" })
-    if (!label) return
-
-    if (!Array.from(this.labels).includes(label)) return
+  formStateRestoreCallback(state, mode) {
 
-    return this.focus()
-  }
-
-  reset() {
-    this.value = this.defaultValue
   }
 }