feat(ui): placeholders updated (#2758)

* data-empty mark

* Update CHANGELOG.md

* lint

* tests added

* Update DataEmpty.cy.ts

* lint

* fix tests

* Update Placeholders.cy.ts

* upd paragraph

* rm redundant test

* lint fix

* disable test for firefox

Author: neSpecc

docs/CHANGELOG.md

@@ -29,6 +29,9 @@
 – `Improvement` — *Types* — `BlockToolConstructorOptions` type improved, `block` and `config` are not optional anymore
 - `Improvement` - The Plus button and Block Tunes toggler are now better aligned with large line-height blocks, such as Headings
 - `Improvement` — Creating links on Android devices: now the mobile keyboard will have an "Enter" key for accepting the inserted link.
+- `Improvement` — Placeholders will stay visible on inputs focus.
+- `New` — Editor.js now supports contenteditable placeholders out of the box. Just add `data-placeholder` or `data-placeholder-active` attribute to make it work. The first one will work like native placeholder while the second one will show placeholder only when block is current.
+- `Improvement` — Now Paragraph placeholder will be shown for the current paragraph, not the only first one.
 
 ### 2.29.1
 

index.html

@@ -203,6 +203,9 @@
        */
       // defaultBlock: 'paragraph',
 
+      placeholder: 'Write something or press / to select a tool',
+      autofocus: true,
+
       /**
        * Initial Editor data
        */

package.json

@@ -45,7 +45,7 @@
     "@editorjs/code": "^2.7.0",
     "@editorjs/delimiter": "^1.2.0",
     "@editorjs/header": "^2.7.0",
-    "@editorjs/paragraph": "^2.11.4",
+    "@editorjs/paragraph": "^2.11.6",
     "@editorjs/simple-image": "^1.4.1",
     "@types/node": "^18.15.11",
     "chai-subset": "^1.6.0",

src/components/block/index.ts

@@ -10,7 +10,7 @@ import {
 } from '../../../types';
 
 import { SavedData } from '../../../types/data-formats';
-import $ from '../dom';
+import $, { toggleEmptyMark } from '../dom';
 import * as _ from '../utils';
 import ApiModules from '../modules/api';
 import BlockAPI from './api';
@@ -183,11 +183,6 @@ export default class Block extends EventsDispatcher<BlockEvents> {
    */
   private unavailableTunesData: { [name: string]: BlockTuneData } = {};
 
-  /**
-   * Editor`s API module
-   */
-  private readonly api: ApiModules;
-
   /**
    * Focused input index
    *
@@ -223,7 +218,6 @@ export default class Block extends EventsDispatcher<BlockEvents> {
     id = _.generateBlockId(),
     data,
     tool,
-    api,
     readOnly,
     tunesData,
   }: BlockConstructorOptions, eventBus?: EventsDispatcher<EditorEventMap>) {
@@ -232,7 +226,6 @@ export default class Block extends EventsDispatcher<BlockEvents> {
     this.id = id;
     this.settings = tool.settings;
     this.config = tool.settings.config || {};
-    this.api = api;
     this.editorEventBus = eventBus || null;
     this.blockAPI = new BlockAPI(this);
 
@@ -262,6 +255,12 @@ export default class Block extends EventsDispatcher<BlockEvents> {
        * so we need to track focus events to update current input and clear cache.
        */
       this.addInputEvents();
+
+      /**
+       * We mark inputs with [data-empty] attribute
+       * It can be useful for developers, for example for correct placeholder behavior
+       */
+      this.toggleInputsEmptyMark();
     });
   }
 
@@ -938,6 +937,11 @@ export default class Block extends EventsDispatcher<BlockEvents> {
      */
     this.updateCurrentInput();
 
+    /**
+     * We mark inputs with 'data-empty' attribute, so new inputs should be marked as well
+     */
+    this.toggleInputsEmptyMark();
+
     this.call(BlockToolAPI.UPDATED);
 
     /**
@@ -1000,4 +1004,11 @@ export default class Block extends EventsDispatcher<BlockEvents> {
   private dropInputsCache(): void {
     this.cachedInputs = [];
   }
+
+  /**
+   * Mark inputs with 'data-empty' attribute with the empty state
+   */
+  private toggleInputsEmptyMark(): void {
+    this.inputs.forEach(toggleEmptyMark);
+  }
 }

src/components/dom.ts

@@ -662,3 +662,13 @@ export function calculateBaseline(element: Element): number {
 
   return baselineY;
 }
+
+/**
+ * Toggles the [data-empty] attribute on element depending on its emptiness
+ * Used to mark empty inputs with a special attribute for placeholders feature
+ *
+ * @param element - The element to toggle the [data-empty] attribute on
+ */
+export function toggleEmptyMark(element: HTMLElement): void {
+  element.dataset.empty = Dom.isEmpty(element) ? 'true' : 'false';
+}

src/components/modules/blockManager.ts

@@ -544,7 +544,7 @@ export default class BlockManager extends Module {
        * If first Block was removed, insert new Initial Block and set focus on it`s first input
        */
       if (!this.blocks.length) {
-        this.currentBlockIndex = -1;
+        this.unsetCurrentBlock();
 
         if (addLastBlock) {
           this.insert();
@@ -591,7 +591,7 @@ export default class BlockManager extends Module {
       this._blocks.remove(index);
     }
 
-    this.currentBlockIndex = -1;
+    this.unsetCurrentBlock();
     this.insert();
     this.currentBlock.firstInput.focus();
   }
@@ -873,7 +873,7 @@ export default class BlockManager extends Module {
    * Sets current Block Index -1 which means unknown
    * and clear highlights
    */
-  public dropPointer(): void {
+  public unsetCurrentBlock(): void {
     this.currentBlockIndex = -1;
   }
 
@@ -895,7 +895,7 @@ export default class BlockManager extends Module {
 
     await queue.completed;
 
-    this.dropPointer();
+    this.unsetCurrentBlock();
 
     if (needToAddDefaultBlock) {
       this.insert();

src/components/modules/ui.ts

@@ -5,7 +5,7 @@
  * @type {UI}
  */
 import Module from '../__module';
-import $ from '../dom';
+import $, { toggleEmptyMark } from '../dom';
 import * as _ from '../utils';
 
 import Selection from '../selection';
@@ -380,6 +380,12 @@ export default class UI extends Module<UINodes> {
      * Start watching 'block-hovered' events that is used by Toolbar for moving
      */
     this.watchBlockHoveredEvents();
+
+    /**
+     * We have custom logic for providing placeholders for contenteditable elements.
+     * To make it work, we need to have data-empty mark on empty inputs.
+     */
+    this.enableInputsEmptyMark();
   }
 
 
@@ -498,7 +504,7 @@ export default class UI extends Module<UINodes> {
     /**
      * Remove all highlights and remove caret
      */
-    this.Editor.BlockManager.dropPointer();
+    this.Editor.BlockManager.unsetCurrentBlock();
 
     /**
      * Close Toolbar
@@ -645,12 +651,12 @@ export default class UI extends Module<UINodes> {
 
     if (!clickedInsideOfEditor) {
       /**
-       * Clear highlights and pointer on BlockManager
+       * Clear pointer on BlockManager
        *
        * Current page might contain several instances
        * Click between instances MUST clear focus, pointers and close toolbars
        */
-      this.Editor.BlockManager.dropPointer();
+      this.Editor.BlockManager.unsetCurrentBlock();
       this.Editor.Toolbar.close();
     }
 
@@ -874,4 +880,28 @@ export default class UI extends Module<UINodes> {
 
     this.Editor.InlineToolbar.tryToShow(true);
   }
+
+  /**
+   * Editor.js provides and ability to show placeholders for empty contenteditable elements
+   *
+   * This method watches for input and focus events and toggles 'data-empty' attribute
+   * to workaroud the case, when inputs contains only <br>s and has no visible content
+   * Then, CSS could rely on this attribute to show placeholders
+   */
+  private enableInputsEmptyMark(): void {
+    /**
+     * Toggle data-empty attribute on input depending on its emptiness
+     *
+     * @param event - input or focus event
+     */
+    function handleInputOrFocusChange(event: Event): void {
+      const input = event.target as HTMLElement;
+
+      toggleEmptyMark(input);
+    }
+
+    this.readOnlyMutableListeners.on(this.nodes.wrapper, 'input', handleInputOrFocusChange);
+    this.readOnlyMutableListeners.on(this.nodes.wrapper, 'focusin', handleInputOrFocusChange);
+    this.readOnlyMutableListeners.on(this.nodes.wrapper, 'focusout', handleInputOrFocusChange);
+  }
 }

src/components/utils/mutations.ts

@@ -7,6 +7,13 @@
 export function isMutationBelongsToElement(mutationRecord: MutationRecord, element: Element): boolean {
   const { type, target, addedNodes, removedNodes } = mutationRecord;
 
+  /**
+   * Skip own technical mutations, for example, data-empty attribute changes
+   */
+  if (mutationRecord.type === 'attributes' && mutationRecord.attributeName === 'data-empty') {
+    return false;
+  }
+
   /**
    * Covers all types of mutations happened to the element or it's descendants with the only one exception - removing/adding the element itself;
    */

src/styles/main.css

@@ -11,4 +11,5 @@
 @import './input.css';
 @import './popover.css';
 @import './popover-inline.css';
+@import './placeholders.css';
 

src/styles/placeholders.css

@@ -0,0 +1,45 @@
+
+/**
+ * We support two types of placeholders for contenteditable:
+ *
+ * 1. Regular-like placeholders. Will be visible when element is empty.
+      -- Best choice for rare-used blocks like Headings.
+ * 2. Current-block placeholders. Will be visible when element is empty and the block is focused.
+      -- Best choice for common-used blocks like Paragraphs.
+ */
+ :root {
+  --placeholder {
+    pointer-events: none;
+    color: var(--grayText);
+    cursor: text;
+  }
+ }
+
+.codex-editor {
+  /**
+   * Use [data-placeholder="..."] to always show a placeholder on empty contenteditable.
+   */
+  [data-placeholder]:empty,
+  [data-placeholder][data-empty="true"] {
+    &::before {
+      @apply --placeholder;
+
+      content: attr(data-placeholder);
+    }
+  }
+
+   /**
+    * Use [data-placeholder-active="..."] to show a placeholder on empty contenteditable in current block.
+    */
+  [data-placeholder-active]:empty,
+  [data-placeholder-active][data-empty="true"] {
+    /* Paragraph tool shows the placeholder for the first block, event it is not focused, so we need to prepare styles for it */
+    &::before {
+      @apply --placeholder;
+    }
+
+    &:focus::before {
+      content: attr(data-placeholder-active);
+    }
+  }
+}