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@lexical/react

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This package provides Lexical components and hooks for React applications.

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/** * Copyright (c) Meta Platforms, Inc. and affiliates. * * This source code is licensed under the MIT license found in the * LICENSE file in the root directory of this source tree. * */ import { useLexicalComposerContext } from '@lexical/react/LexicalComposerContext'; import { useEffect, useState, useMemo } from 'react'; import { OverflowNode, $isOverflowNode, $createOverflowNode } from '@lexical/overflow'; import { $rootTextContent } from '@lexical/text'; import { mergeRegister, $dfs, $unwrapNode } from '@lexical/utils'; import { DELETE_CHARACTER_COMMAND, $getSelection, $isRangeSelection, $isElementNode, COMMAND_PRIORITY_LOW, $isTextNode, $isLeafNode, $setSelection } from 'lexical'; import { jsx } from 'react/jsx-runtime'; /** * Copyright (c) Meta Platforms, Inc. and affiliates. * * This source code is licensed under the MIT license found in the * LICENSE file in the root directory of this source tree. * */ // Do not require this module directly! Use normal `invariant` calls. function formatDevErrorMessage(message) { throw new Error(message); } function useCharacterLimit(editor, maxCharacters, optional = Object.freeze({})) { const { strlen = input => input.length, // UTF-16 remainingCharacters = () => { return; } } = optional; useEffect(() => { if (!editor.hasNodes([OverflowNode])) { { formatDevErrorMessage(`useCharacterLimit: OverflowNode not registered on editor`); } } }, [editor]); useEffect(() => { let text = editor.getEditorState().read($rootTextContent); let lastComputedTextLength = 0; return mergeRegister(editor.registerTextContentListener(currentText => { text = currentText; }), editor.registerUpdateListener(({ dirtyLeaves, dirtyElements }) => { const isComposing = editor.isComposing(); const hasContentChanges = dirtyLeaves.size > 0 || dirtyElements.size > 0; if (isComposing || !hasContentChanges) { return; } const textLength = strlen(text); const textLengthAboveThreshold = textLength > maxCharacters || lastComputedTextLength !== null && lastComputedTextLength > maxCharacters; const diff = maxCharacters - textLength; remainingCharacters(diff); if (lastComputedTextLength === null || textLengthAboveThreshold) { const offset = findOffset(text, maxCharacters, strlen); editor.update(() => { $wrapOverflowedNodes(offset); }, { tag: 'history-merge' }); } lastComputedTextLength = textLength; }), editor.registerCommand(DELETE_CHARACTER_COMMAND, isBackward => { const selection = $getSelection(); if (!$isRangeSelection(selection)) { return false; } const anchorNode = selection.anchor.getNode(); const overflow = anchorNode.getParent(); const overflowParent = overflow ? overflow.getParent() : null; const parentNext = overflowParent ? overflowParent.getNextSibling() : null; selection.deleteCharacter(isBackward); if (overflowParent && overflowParent.isEmpty()) { overflowParent.remove(); } else if ($isElementNode(parentNext) && parentNext.isEmpty()) { parentNext.remove(); } return true; }, COMMAND_PRIORITY_LOW)); }, [editor, maxCharacters, remainingCharacters, strlen]); } function findOffset(text, maxCharacters, strlen) { const Segmenter = Intl.Segmenter; let offsetUtf16 = 0; let offset = 0; if (typeof Segmenter === 'function') { const segmenter = new Segmenter(); const graphemes = segmenter.segment(text); for (const { segment: grapheme } of graphemes) { const nextOffset = offset + strlen(grapheme); if (nextOffset > maxCharacters) { break; } offset = nextOffset; offsetUtf16 += grapheme.length; } } else { const codepoints = Array.from(text); const codepointsLength = codepoints.length; for (let i = 0; i < codepointsLength; i++) { const codepoint = codepoints[i]; const nextOffset = offset + strlen(codepoint); if (nextOffset > maxCharacters) { break; } offset = nextOffset; offsetUtf16 += codepoint.length; } } return offsetUtf16; } function $wrapOverflowedNodes(offset) { const dfsNodes = $dfs(); const dfsNodesLength = dfsNodes.length; let accumulatedLength = 0; for (let i = 0; i < dfsNodesLength; i += 1) { const { node } = dfsNodes[i]; if ($isOverflowNode(node)) { const previousLength = accumulatedLength; const nextLength = accumulatedLength + node.getTextContentSize(); if (nextLength <= offset) { const parent = node.getParent(); const previousSibling = node.getPreviousSibling(); const nextSibling = node.getNextSibling(); $unwrapNode(node); const selection = $getSelection(); // Restore selection when the overflow children are removed if ($isRangeSelection(selection) && (!selection.anchor.getNode().isAttached() || !selection.focus.getNode().isAttached())) { if ($isTextNode(previousSibling)) { previousSibling.select(); } else if ($isTextNode(nextSibling)) { nextSibling.select(); } else if (parent !== null) { parent.select(); } } } else if (previousLength < offset) { const descendant = node.getFirstDescendant(); const descendantLength = descendant !== null ? descendant.getTextContentSize() : 0; const previousPlusDescendantLength = previousLength + descendantLength; // For simple text we can redimension the overflow into a smaller and more accurate // container const firstDescendantIsSimpleText = $isTextNode(descendant) && descendant.isSimpleText(); const firstDescendantDoesNotOverflow = previousPlusDescendantLength <= offset; if (firstDescendantIsSimpleText || firstDescendantDoesNotOverflow) { $unwrapNode(node); } } } else if ($isLeafNode(node)) { const previousAccumulatedLength = accumulatedLength; accumulatedLength += node.getTextContentSize(); if (accumulatedLength > offset && !$isOverflowNode(node.getParent())) { const previousSelection = $getSelection(); let overflowNode; // For simple text we can improve the limit accuracy by splitting the TextNode // on the split point if (previousAccumulatedLength < offset && $isTextNode(node) && node.isSimpleText()) { const [, overflowedText] = node.splitText(offset - previousAccumulatedLength); overflowNode = $wrapNode(overflowedText); } else { overflowNode = $wrapNode(node); } if (previousSelection !== null) { $setSelection(previousSelection); } $mergePrevious(overflowNode); } } } } function $wrapNode(node) { const overflowNode = $createOverflowNode(); node.replace(overflowNode); overflowNode.append(node); return overflowNode; } function $mergePrevious(overflowNode) { const previousNode = overflowNode.getPreviousSibling(); if (!$isOverflowNode(previousNode)) { return; } const firstChild = overflowNode.getFirstChild(); const previousNodeChildren = previousNode.getChildren(); const previousNodeChildrenLength = previousNodeChildren.length; if (firstChild === null) { overflowNode.append(...previousNodeChildren); } else { for (let i = 0; i < previousNodeChildrenLength; i++) { firstChild.insertBefore(previousNodeChildren[i]); } } const selection = $getSelection(); if ($isRangeSelection(selection)) { const anchor = selection.anchor; const anchorNode = anchor.getNode(); const focus = selection.focus; const focusNode = anchor.getNode(); if (anchorNode.is(previousNode)) { anchor.set(overflowNode.getKey(), anchor.offset, 'element'); } else if (anchorNode.is(overflowNode)) { anchor.set(overflowNode.getKey(), previousNodeChildrenLength + anchor.offset, 'element'); } if (focusNode.is(previousNode)) { focus.set(overflowNode.getKey(), focus.offset, 'element'); } else if (focusNode.is(overflowNode)) { focus.set(overflowNode.getKey(), previousNodeChildrenLength + focus.offset, 'element'); } } previousNode.remove(); } /** * Copyright (c) Meta Platforms, Inc. and affiliates. * * This source code is licensed under the MIT license found in the * LICENSE file in the root directory of this source tree. * */ const CHARACTER_LIMIT = 5; let textEncoderInstance = null; function textEncoder() { if (window.TextEncoder === undefined) { return null; } if (textEncoderInstance === null) { textEncoderInstance = new window.TextEncoder(); } return textEncoderInstance; } function utf8Length(text) { const currentTextEncoder = textEncoder(); if (currentTextEncoder === null) { // http://stackoverflow.com/a/5515960/210370 const m = encodeURIComponent(text).match(/%[89ABab]/g); return text.length + (m ? m.length : 0); } return currentTextEncoder.encode(text).length; } function DefaultRenderer({ remainingCharacters }) { return /*#__PURE__*/jsx("span", { className: `characters-limit ${remainingCharacters < 0 ? 'characters-limit-exceeded' : ''}`, children: remainingCharacters }); } function CharacterLimitPlugin({ charset = 'UTF-16', maxLength = CHARACTER_LIMIT, renderer = DefaultRenderer }) { const [editor] = useLexicalComposerContext(); const [remainingCharacters, setRemainingCharacters] = useState(maxLength); const characterLimitProps = useMemo(() => ({ remainingCharacters: setRemainingCharacters, strlen: text => { if (charset === 'UTF-8') { return utf8Length(text); } else if (charset === 'UTF-16') { return text.length; } else { throw new Error('Unrecognized charset'); } } }), [charset]); useCharacterLimit(editor, maxLength, characterLimitProps); return renderer({ remainingCharacters }); } export { CharacterLimitPlugin };