DEV: refactor textarea from autocomplete (#29988)

Extracts the dependency we had on specifics of a textarea in our Autocomplete, this approach uses a TextareaTextManipulation, particularly the value getter, getCaretPosition, getCaretCoords, replaceText, and inCodeBlock.

app/assets/javascripts/discourse/app/components/d-editor.js

@@ -306,8 +306,7 @@ export default class DEditor extends Component {
         this.site.hashtag_configurations["topic-composer"],
         this.siteSettings,
         {
-          afterComplete: (value) => {
+          afterComplete: () => {
-            this.set("value", value);
             schedule(
               "afterRender",
               this.textManipulation,
@@ -327,8 +326,7 @@ export default class DEditor extends Component {
     this.textManipulation.autocomplete({
       template: findRawTemplate("emoji-selector-autocomplete"),
       key: ":",
-      afterComplete: (text) => {
+      afterComplete: () => {
-        this.set("value", text);
         schedule(
           "afterRender",
           this.textManipulation,
@@ -466,9 +464,7 @@ export default class DEditor extends Component {
       onRender: (options) => renderUserStatusHtml(options),
       key: "@",
       transformComplete: (v) => v.username || v.name,
-      afterComplete: (value) => {
+      afterComplete: () => {
-        this.set("value", value);
-
         schedule(
           "afterRender",
           this.textManipulation,

app/assets/javascripts/discourse/app/lib/autocomplete.js

@@ -2,7 +2,7 @@ import { cancel } from "@ember/runloop";
 import { createPopper } from "@popperjs/core";
 import $ from "jquery";
 import { isDocumentRTL } from "discourse/lib/text-direction";
-import { caretPosition, setCaretPosition } from "discourse/lib/utilities";
+import { TextareaAutocompleteHandler } from "discourse/lib/textarea-text-manipulation";
 import Site from "discourse/models/site";
 import { INPUT_DELAY } from "discourse-common/config/environment";
 import discourseDebounce from "discourse-common/lib/debounce";
@@ -114,6 +114,8 @@ export default function (options) {
   const isInput = me[0].tagName === "INPUT" && !options.treatAsTextarea;
   let inputSelectedItems = [];
 
+  options.textHandler ??= new TextareaAutocompleteHandler(me[0]);
+
   function handlePaste() {
     discourseLater(() => me.trigger("keydown"), 50);
   }
@@ -216,8 +218,6 @@ export default function (options) {
   }
 
   let completeTerm = async function (term, event) {
-    let completeEnd = null;
-
     if (term) {
       if (isInput) {
         me.val("");
@@ -231,15 +231,13 @@ export default function (options) {
         }
 
         if (term) {
-          let text = me.val();
-
           // After completion is done our position for completeStart may have
           // drifted. This can happen if the TEXTAREA changed out-of-band between
           // the time autocomplete was first displayed and the time of completion
           // Specifically this may happen due to uploads which inject a placeholder
           // which is later replaced with a different length string.
           let pos = await guessCompletePosition({ completeTerm: true });
-
+          let completeEnd = null;
           if (
             pos.completeStart !== undefined &&
             pos.completeEnd !== undefined
@@ -247,31 +245,18 @@ export default function (options) {
             completeStart = pos.completeStart;
             completeEnd = pos.completeEnd;
           } else {
-            completeStart = completeEnd = caretPosition(me[0]);
+            completeStart = completeEnd =
+              options.textHandler.getCaretPosition();
           }
 
-          let space =
+          options.textHandler.replaceTerm({
-            text.substring(completeEnd + 1, completeEnd + 2) === " " ? "" : " ";
+            start: completeStart,
-
+            end: completeEnd,
-          text =
+            term: (options.preserveKey ? options.key || "" : "") + term,
-            text.substring(0, completeStart) +
+          });
-            (options.preserveKey ? options.key || "" : "") +
-            term +
-            space +
-            text.substring(completeEnd + 1, text.length);
-
-          me.val(text);
-
-          let newCaretPos = completeStart + 1 + term.length;
-
-          if (options.key) {
-            newCaretPos++;
-          }
-
-          setCaretPosition(me[0], newCaretPos);
 
           if (options && options.afterComplete) {
-            options.afterComplete(text, event);
+            options.afterComplete(options.textHandler.value, event);
           }
         }
       }
@@ -429,9 +414,7 @@ export default function (options) {
     }
 
     let vOffset = 0;
-    let pos = me.caretPosition({
+    let pos = options.textHandler.getCaretCoords(completeStart);
-      pos: completeStart + 1,
-    });
 
     if (options.treatAsTextarea) {
       vOffset = -32;
@@ -539,7 +522,11 @@ export default function (options) {
     closeAutocomplete();
   });
 
-  async function checkTriggerRule(opts) {
+  async function checkTriggerRule(_opts) {
+    const opts = {
+      ..._opts,
+      inCodeBlock: () => options.textHandler.inCodeBlock(),
+    };
     const shouldTrigger = await options.triggerRule?.(me[0], opts);
     return shouldTrigger ?? true;
   }
@@ -557,12 +544,12 @@ export default function (options) {
       return true;
     }
 
-    let cp = caretPosition(me[0]);
+    let cp = options.textHandler.getCaretPosition();
-    const key = me[0].value[cp - 1];
+    const key = options.textHandler.value[cp - 1];
 
     if (options.key) {
       if (options.onKeyUp && key !== options.key) {
-        let match = options.onKeyUp(me.val(), cp);
+        let match = options.onKeyUp(options.textHandler.value, cp);
 
         if (match) {
           completeStart = cp - match[0].length;
@@ -574,10 +561,9 @@ export default function (options) {
 
     if (completeStart === null && cp > 0) {
       if (key === options.key) {
-        let prevChar = me.val().charAt(cp - 2);
+        let prevChar = options.textHandler.value.charAt(cp - 2);
-        const shouldTrigger = await checkTriggerRule();
         if (
-          shouldTrigger &&
+          (await checkTriggerRule()) &&
           (!prevChar || ALLOWED_LETTERS_REGEXP.test(prevChar))
         ) {
           completeStart = cp - 1;
@@ -585,7 +571,10 @@ export default function (options) {
         }
       }
     } else if (completeStart !== null) {
-      let term = me.val().substring(completeStart + (options.key ? 1 : 0), cp);
+      let term = options.textHandler.value.substring(
+        completeStart + (options.key ? 1 : 0),
+        cp
+      );
       updateAutoComplete(dataSource(term, options));
     }
   }
@@ -593,10 +582,9 @@ export default function (options) {
   async function guessCompletePosition(opts) {
     let prev, stopFound, term;
     let prevIsGood = true;
-    let element = me[0];
     let backSpace = opts?.backSpace;
     let completeTermOption = opts?.completeTerm;
-    let caretPos = caretPosition(element);
+    let caretPos = options.textHandler.getCaretPosition();
 
     if (backSpace) {
       caretPos -= 1;
@@ -609,12 +597,12 @@ export default function (options) {
 
     while (prevIsGood && caretPos >= 0) {
       caretPos -= 1;
-      prev = element.value[caretPos];
+      prev = options.textHandler.value[caretPos];
 
       stopFound = prev === options.key;
 
       if (stopFound) {
-        prev = element.value[caretPos - 1];
+        prev = options.textHandler.value[caretPos - 1];
         const shouldTrigger = await checkTriggerRule({ backSpace });
 
         if (
@@ -622,7 +610,10 @@ export default function (options) {
           (prev === undefined || ALLOWED_LETTERS_REGEXP.test(prev))
         ) {
           start = caretPos;
-          term = element.value.substring(caretPos + 1, initialCaretPos);
+          term = options.textHandler.value.substring(
+            caretPos + 1,
+            initialCaretPos
+          );
           end = caretPos + term.length;
           break;
         }
@@ -653,9 +644,10 @@ export default function (options) {
           inputSelectedItems.push("");
         }
 
-        if (typeof inputSelectedItems[0] === "string" && me.val().length > 0) {
+        const value = options.textHandler.value;
+        if (typeof inputSelectedItems[0] === "string" && value.length > 0) {
           inputSelectedItems.pop();
-          inputSelectedItems.push(me.val());
+          inputSelectedItems.push(value);
           if (options.onChangeItems) {
             options.onChangeItems(inputSelectedItems);
           }
@@ -693,10 +685,13 @@ export default function (options) {
     }
 
     if (completeStart !== null) {
-      cp = caretPosition(me[0]);
+      cp = options.textHandler.getCaretPosition();
 
       // allow people to right arrow out of completion
-      if (e.which === keys.rightArrow && me[0].value[cp] === " ") {
+      if (
+        e.which === keys.rightArrow &&
+        options.textHandler.value[cp] === " "
+      ) {
         closeAutocomplete();
         return true;
       }
@@ -771,7 +766,10 @@ export default function (options) {
             return true;
           }
 
-          term = me.val().substring(completeStart + (options.key ? 1 : 0), cp);
+          term = options.textHandler.value.substring(
+            completeStart + (options.key ? 1 : 0),
+            cp
+          );
 
           if (completeStart === cp && term === options.key) {
             closeAutocomplete();

app/assets/javascripts/discourse/app/lib/hashtag-autocomplete.js

@@ -4,11 +4,7 @@ import { ajax } from "discourse/lib/ajax";
 import { CANCELLED_STATUS } from "discourse/lib/autocomplete";
 import { getHashtagTypeClasses as getHashtagTypeClassesNew } from "discourse/lib/hashtag-type-registry";
 import { emojiUnescape } from "discourse/lib/text";
-import {
+import { escapeExpression } from "discourse/lib/utilities";
-  caretPosition,
-  escapeExpression,
-  inCodeBlock,
-} from "discourse/lib/utilities";
 import { INPUT_DELAY, isTesting } from "discourse-common/config/environment";
 import discourseDebounce from "discourse-common/lib/debounce";
 import discourseLater from "discourse-common/lib/later";
@@ -50,8 +46,8 @@ export function setupHashtagAutocomplete(
   );
 }
 
-export async function hashtagTriggerRule(textarea) {
+export async function hashtagTriggerRule(textarea, { inCodeBlock }) {
-  return !(await inCodeBlock(textarea.value, caretPosition(textarea)));
+  return !(await inCodeBlock());
 }
 
 export function hashtagAutocompleteOptions(
@@ -62,8 +58,6 @@ export function hashtagAutocompleteOptions(
   return {
     template: findRawTemplate("hashtag-autocomplete"),
     key: "#",
-    afterComplete: autocompleteOptions.afterComplete,
-    treatAsTextarea: autocompleteOptions.treatAsTextarea,
     scrollElementSelector: ".hashtag-autocomplete__fadeout",
     autoSelectFirstSuggestion: true,
     transformComplete: (obj) => obj.ref,
@@ -75,6 +69,7 @@ export function hashtagAutocompleteOptions(
     },
     triggerRule: async (textarea, opts) =>
       await hashtagTriggerRule(textarea, opts),
+    ...autocompleteOptions,
   };
 }
 

app/assets/javascripts/discourse/app/lib/textarea-text-manipulation.js

@@ -12,6 +12,7 @@ import {
   clipboardHelpers,
   determinePostReplaceSelection,
   inCodeBlock,
+  setCaretPosition,
 } from "discourse/lib/utilities";
 import { isTesting } from "discourse-common/config/environment";
 import { bind } from "discourse-common/utils/decorators";
@@ -52,6 +53,7 @@ export default class TextareaTextManipulation {
   textarea;
   $textarea;
 
+  autocompleteHandler;
   placeholder;
 
   constructor(owner, { markdownOptions, textarea, eventPrefix = "composer" }) {
@@ -62,6 +64,8 @@ export default class TextareaTextManipulation {
     this.textarea = textarea;
     this.$textarea = $(textarea);
 
+    this.autocompleteHandler = new TextareaAutocompleteHandler(textarea);
+
     generateLinkifyFunction(markdownOptions || {}).then((linkify) => {
       // When pasting links, we should use the same rules to match links as we do when creating links for a cooked post.
       this._cachedLinkify = linkify;
@@ -349,13 +353,7 @@ export default class TextareaTextManipulation {
   }
 
   _insertAt(start, end, text) {
-    this.textarea.setSelectionRange(start, end);
+    insertAtTextarea(this.textarea, start, end, text);
-    this.textarea.focus();
-    if (start !== end && text === "") {
-      document.execCommand("delete", false);
-    } else {
-      document.execCommand("insertText", false, text);
-    }
   }
 
   extractTable(text) {
@@ -742,7 +740,6 @@ export default class TextareaTextManipulation {
     }
   }
 
-  @bind
   async inCodeBlock() {
     return inCodeBlock(
       this.$textarea.value ?? this.$textarea.val(),
@@ -829,8 +826,57 @@ export default class TextareaTextManipulation {
     putCursorAtEnd(this.textarea);
   }
 
-  autocomplete() {
+  autocomplete(options) {
-    return this.$textarea.autocomplete(...arguments);
+    return this.$textarea.autocomplete(
+      options instanceof Object
+        ? { textHandler: this.autocompleteHandler, ...options }
+        : options
+    );
+  }
+}
+
+function insertAtTextarea(textarea, start, end, text) {
+  textarea.setSelectionRange(start, end);
+  textarea.focus();
+  if (start !== end && text === "") {
+    document.execCommand("delete", false);
+  } else {
+    document.execCommand("insertText", false, text);
+  }
+}
+
+export class TextareaAutocompleteHandler {
+  textarea;
+  $textarea;
+
+  constructor(textarea) {
+    this.textarea = textarea;
+    this.$textarea = $(textarea);
+  }
+
+  get value() {
+    return this.textarea.value;
+  }
+
+  replaceTerm({ start, end, term }) {
+    const space = this.value.substring(end + 1, end + 2) === " " ? "" : " ";
+    insertAtTextarea(this.textarea, start, end + 1, term + space);
+    setCaretPosition(this.textarea, start + 1 + term.trim().length);
+  }
+
+  getCaretPosition() {
+    return caretPosition(this.textarea);
+  }
+
+  getCaretCoords(start) {
+    return this.$textarea.caretPosition({ pos: start + 1 });
+  }
+
+  async inCodeBlock() {
+    return inCodeBlock(
+      this.$textarea.value ?? this.$textarea.val(),
+      caretPosition(this.$textarea)
+    );
   }
 }
 

app/assets/javascripts/discourse/tests/unit/lib/autocomplete-test.js

@@ -151,4 +151,22 @@ module("Unit | Utility | autocomplete", function (hooks) {
     assert.dom("#ac-testing li a.selected").exists({ count: 1 });
     assert.dom("#ac-testing li a.selected").hasText("test1");
   });
+
+  test("Autocomplete doesn't reset undo history", async function (assert) {
+    const element = textArea();
+
+    $(element).autocomplete({
+      key: "@",
+      template,
+      dataSource: () => ["test1", "test2"],
+    });
+
+    await simulateKeys(element, "@t\r");
+
+    assert.strictEqual(element.value, "@test1 ");
+
+    document.execCommand("undo");
+
+    assert.strictEqual(element.value, "@t");
+  });
 });