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Cursor Rule Markdown Renderer for GitHub

Renders Cursor Rules (*.mdc) markdown on GitHub into actual Markdown locally, using the marked library + highlight.js.

当前为 2025-05-30 提交的版本，查看 最新版本。

  1. // ==UserScript==
  2. // @name         Cursor Rule Markdown Renderer for GitHub
  3. // @namespace    https://github.com/texarkanine
  4. // @version      1.3.0
  5. // @description  Renders Cursor Rules (*.mdc) markdown on GitHub into actual Markdown locally, using the marked library + highlight.js.
  6. // @author       Texarkanine
  7. // @licence      GPLv3
  8. // @homepageURL  https://github.com/texarkanine/client-side-mdc-render
  9. // @supportURL   https://github.com/texarkanine/client-side-mdc-render/issues
  10. // @match        https://github.com/*
  11. // @icon         data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAANAAAACACAMAAABN9BexAAABRFBMVEUAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD///8NAl4NAAAAanRSTlMAAQIDBQcICQsMDg8SGBsfJSo2ODk6Ozw9P0FCREpQUVJTVFpfYWZnbHN0dXZ3eHl7gIKDhYaIiYqLjJiZnqCkp6ipr7CxsrO0vr/BwsPGx8nR1dfY2eDh4uPk5+jp7PHy8/T19vj5+v3+PVg6RwAAAAFiS0dEa1JlpZgAAAPiSURBVHja7d1rWxJBGAbgB3ABK+mgIZqVaUHhqXMQlNnJU6FFWYJWaB6Y//8D+iDsidnd2WXXeOea9xN+4IL7kn3mmUEB6E4iV96sHzByc1DfLI8nYJ/Uwj4jPPvzKatnZpcRn90ZEyf2qM3IT/t5vOuJv2VSzEpX9IxJMk86109bFlB7GgCSP5k000gBWGQSzRyQ2JcJtBdHzvTj+4k0yE164qOJkMVL44dFEJ0lw1DGhvH7AdlZ1RHr+K7fnqALmtQR39DSb6fpgoZ1RAvGyw+Ex6RQIAVSIAVSIAVSIAVSIAVSoP8D4h1E5MUeo8C7r6/n5uNufYFOciKesSMyINbMeD+tkQajA2JbmtcDDH1ilEDstdcDVBktkFcwFBg1kHsw8ANhoEGuweAQCIMNcgkGp0AYcJBzMFQZTZBTMBQYVRA/GJwDYeBB3GBwCYTBB3GCwS0QCIB6g6HKaIPswVBg1EHWYHAPBBIgSzB4BAINkCkYvAKBCMgIhiqTA9QNhgKTBXQWDN6BQAbEmhmhQKADYluaSCAQArFqlckFEh4FUiAFYkwwACpkQGIRXdPIgIQW0WYGdEAY9aw5JzlQAuGuSGGlBPLaKlRADeQeDDVN8JmVgy8ApXBBrsHQ2ZYLgGKvgnqWYyGDXIKhe3Ai8tpJvAvmWRtC2CDnYMj7uRhSn4N4ttMIH+QUDBV/V/fFL/49Xy8hChA/GGqaz7jK7Pj1NC4jEhA3GEzndKL5e8Xn/8f8uoqIQJxgMJ+kCi8o11p+PH+ziAzUGwz5QCvk1LG45+QmIgTZg6EScMmfPRX1tO8hUpA1GGpa0A5zXxRURLQgSzDY3tHzVcoES1AJUYNMwWB/z9UXSKwE2QpPJCAjGPJ91WaREmQvPNGAusFQ6XMf4F2CttM4F9BZMNS0fjc2XiWot/BEBMJIg/sWv++dmnsJ4hSeqEAYPeL9EYb/radbCeIVnshAyOfD2UuPHTp5DsdwnqDQDgecShC/8BAAOZQgh8JDAcQvQUXQBfFKUAmUQb0lyLHw0AD1lCDnwkMEZCtB22lQB1lKkFvhIQMylSDXwkMHpJcg98JDCNQ5CeKe8NAEYerYu/CQAmH21LPw0AKhWET4ICqjQAqkQAqkQAqkQAqkQAqkQOcA+qPfHKbruaAjfsv3oZMb+u0PdEFrOmLdfDa+RNXz0DC8wLhpx786SfA6Gr6xZiJcl+zDj5txYF4m0AMAyR/yeHZTAHBHno94v312WT2VBfS4kxPxFTk8b/QvfogtyPVFFgCmySfDzi3r8pSc2yO9/hSTPStuPFvaqLfoWVr19VLWeLX9A7BB7+nmPT+tAAAAAElFTkSuQmCC
  12. // @grant        GM_addStyle
  13. // @require      https://cdnjs.cloudflare.com/ajax/libs/marked/15.0.7/marked.min.js
  14. // @require      https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.11.1/highlight.min.js
  15. // ==/UserScript==
  16.  
  17. (function() {
  18. 	'use strict';
  19.  
  20. 	const DEBUG = true;
  21.  
  22. 	const MDC_FILE_REGEX = /^https:\/\/github\.com\/.*\.mdc$/;
  23. 	const YAML_FRONTMATTER_REGEX = /^---\s*\n([\s\S]*?)\n---\s*\n([\s\S]*)$/;
  24.  
  25. 	const RENDERED_LABEL = 'M⇩';
  26. 	const SOURCE_LABEL = '.mdc';
  27.  
  28. 	const MAX_RENDER_ATTEMPTS = 50;
  29. 	const RENDER_RETRY_INTERVAL = 100;
  30.  
  31. 	const RENDERED_ID = 'client-side-mdc-markdown';
  32.  
  33. 	let currentUrl = location.href;
  34. 	let isActive = false;
  35. 	let textareaObserver = null;
  36.  
  37. 	GM_addStyle(`
  38. 		#client-side-mdc-markdown {
  39. 			box-sizing: border-box;
  40. 			min-width: 200px;
  41. 			max-width: 980px;
  42. 			margin: 24px auto 0;
  43. 			padding: 45px;
  44. 			word-wrap: break-word;
  45. 		}
  46. 	`);
  47.  
  48. 	/**
  49. 	 * Processes MDC content by extracting YAML frontmatter and converting it to a code block
  50. 	 * @param {string} content - Raw MDC file content
  51. 	 * @returns {string} Processed content with YAML frontmatter as code block
  52. 	 */
  53. 	function processContent(content) {
  54. 		const match = content.match(YAML_FRONTMATTER_REGEX);
  55. 		if (match) {
  56. 			const [, yamlContent, markdownContent] = match;
  57. 			return `\`\`\`yaml\n${yamlContent}\n\`\`\`\n\n${markdownContent}`;
  58. 		}
  59. 		return content;
  60. 	}
  61.  
  62. 	/**
  63. 	 * Creates a button element with GitHub's styling
  64. 	 * @param {string} label - Button text content
  65. 	 * @param {string} mode - View mode ('rendered' or 'source')
  66. 	 * @param {boolean} isSelected - Whether button should be in selected state
  67. 	 * @returns {HTMLLIElement} Complete button list item element
  68. 	 */
  69. 	function createButton(label, mode, isSelected = false) {
  70. 		const li = document.createElement('li');
  71. 		li.className = `SegmentedControl-item${isSelected ? ' SegmentedControl-item--selected' : ''}`;
  72. 		li.setAttribute('role', 'listitem');
  73.  
  74. 		const button = document.createElement('button');
  75. 		button.setAttribute('aria-current', isSelected.toString());
  76. 		button.setAttribute('type', 'button');
  77. 		button.setAttribute('data-view-component', 'true');
  78. 		button.className = 'Button--invisible Button--small Button Button--invisible-noVisuals';
  79. 		button.onclick = () => setViewMode(mode);
  80.  
  81. 		const content = document.createElement('span');
  82. 		content.className = 'Button-content';
  83. 		const labelSpan = document.createElement('span');
  84. 		labelSpan.className = 'Button-label';
  85. 		labelSpan.setAttribute('data-content', label);
  86. 		labelSpan.textContent = label;
  87.  
  88. 		content.appendChild(labelSpan);
  89. 		button.appendChild(content);
  90. 		li.appendChild(button);
  91.  
  92. 		return li;
  93. 	}
  94.  
  95. 	/**
  96. 	 * Creates a GitHub-styled segmented control for toggling between rendered and source views
  97. 	 * @returns {HTMLDivElement} Complete toggle button control
  98. 	 */
  99. 	function createToggleButton() {
  100. 		const container = document.createElement('div');
  101. 		container.className = 'mdc-segmented-control';
  102.  
  103. 		const segmentedControl = document.createElement('segmented-control');
  104. 		segmentedControl.setAttribute('data-catalyst', '');
  105.  
  106. 		const ul = document.createElement('ul');
  107. 		ul.setAttribute('aria-label', 'MDC view');
  108. 		ul.setAttribute('role', 'list');
  109. 		ul.setAttribute('data-view-component', 'true');
  110. 		ul.className = 'SegmentedControl--small SegmentedControl';
  111.  
  112. 		ul.appendChild(createButton(RENDERED_LABEL, 'rendered', true));
  113. 		ul.appendChild(createButton(SOURCE_LABEL, 'source', false));
  114.  
  115. 		segmentedControl.appendChild(ul);
  116. 		container.appendChild(segmentedControl);
  117.  
  118. 		return container;
  119. 	}
  120.  
  121. 	/**
  122. 	 * Switches between rendered markdown and source code views
  123. 	 * @param {'rendered'|'source'} mode - View mode to activate
  124. 	 */
  125. 	function setViewMode(mode) {
  126. 		const rendered = document.getElementById(RENDERED_ID);
  127. 		const original = document.querySelector('#read-only-cursor-text-area')?.closest('section');
  128. 		const buttons = document.querySelectorAll('.mdc-segmented-control .SegmentedControl-item');
  129.  
  130. 		if (!rendered || !original || buttons.length !== 2) return;
  131.  
  132. 		const [renderedItem, sourceItem] = buttons;
  133. 		const renderedButton = renderedItem.querySelector('button');
  134. 		const sourceButton = sourceItem.querySelector('button');
  135.  
  136. 		const isRenderedMode = mode === 'rendered';
  137.  
  138. 		rendered.style.display = isRenderedMode ? 'block' : 'none';
  139. 		original.style.display = isRenderedMode ? 'none' : 'block';
  140.  
  141. 		renderedItem.classList.toggle('SegmentedControl-item--selected', isRenderedMode);
  142. 		sourceItem.classList.toggle('SegmentedControl-item--selected', !isRenderedMode);
  143.  
  144. 		if (renderedButton) renderedButton.setAttribute('aria-current', isRenderedMode.toString());
  145. 		if (sourceButton) sourceButton.setAttribute('aria-current', (!isRenderedMode).toString());
  146. 	}
  147.  
  148. 	/**
  149. 	 * Renders MDC content as HTML and inserts it into the page
  150. 	 * @returns {boolean} True if rendering was successful, false otherwise
  151. 	 */
  152. 	function renderMDC() {
  153. 		const textarea = document.querySelector('#read-only-cursor-text-area');
  154. 		if (!textarea) {
  155. 			DEBUG && console.log('[mdc-lite] No textarea found');
  156. 			return false;
  157. 		}
  158.  
  159. 		const content = textarea.textContent?.trim();
  160. 		if (!content) {
  161. 			DEBUG && console.log('[mdc-lite] No content in textarea');
  162. 			return false;
  163. 		}
  164.  
  165. 		const existing = document.getElementById(RENDERED_ID);
  166. 		existing?.remove();
  167.  
  168. 		const processedContent = processContent(content);
  169. 		const rendered = document.createElement('div');
  170. 		rendered.id = RENDERED_ID;
  171. 		rendered.className = 'markdown-body';
  172. 		rendered.innerHTML = marked.parse(processedContent);
  173.  
  174. 		rendered.querySelectorAll('pre code').forEach(block => {
  175. 			hljs.highlightElement(block);
  176. 		});
  177.  
  178. 		const section = textarea.closest('section');
  179. 		if (!section?.parentElement) {
  180. 			DEBUG && console.log('[mdc-lite] Could not find section to insert rendered content');
  181. 			return false;
  182. 		}
  183.  
  184. 		section.parentElement.insertBefore(rendered, section);
  185. 		section.style.display = 'none';
  186.  
  187. 		const toolbar = document.querySelector('.react-blob-header-edit-and-raw-actions');
  188. 		if (toolbar && !toolbar.querySelector('.mdc-segmented-control')) {
  189. 			toolbar.insertBefore(createToggleButton(), toolbar.firstChild);
  190. 		}
  191.  
  192. 		// Ensure toggle reflects actual display state (always rendered initially)
  193. 		setViewMode('rendered');
  194.  
  195. 		DEBUG && console.log('[mdc-lite] Successfully rendered MDC');
  196. 		return true;
  197. 	}
  198.  
  199. 	/**
  200. 	 * Removes all MDC-related elements and restores original state
  201. 	 */
  202. 	function cleanup() {
  203. 		document.getElementById(RENDERED_ID)?.remove();
  204. 		document.querySelector('.mdc-segmented-control')?.remove();
  205.  
  206. 		const original = document.querySelector('#read-only-cursor-text-area')?.closest('section');
  207. 		if (original) original.style.display = 'block';
  208.  
  209. 		if (textareaObserver) {
  210. 			textareaObserver.disconnect();
  211. 			textareaObserver = null;
  212. 		}
  213.  
  214. 		isActive = false;
  215. 		DEBUG && console.log('[mdc-lite] Cleaned up');
  216. 	}
  217.  
  218. 	/**
  219. 	 * Sets up a MutationObserver to watch for textarea content changes and re-render accordingly
  220. 	 * @returns {boolean} True if observer was successfully set up, false otherwise
  221. 	 */
  222. 	function setupTextareaObserver() {
  223. 		const textarea = document.querySelector('#read-only-cursor-text-area');
  224. 		if (!textarea) return false;
  225.  
  226. 		textareaObserver?.disconnect();
  227.  
  228. 		textareaObserver = new MutationObserver(() => {
  229. 			DEBUG && console.log('[mdc-lite] Textarea content changed, re-rendering');
  230. 			renderMDC();
  231. 		});
  232.  
  233. 		textareaObserver.observe(textarea, {
  234. 			childList: true,
  235. 			subtree: true,
  236. 			characterData: true
  237. 		});
  238.  
  239. 		DEBUG && console.log('[mdc-lite] Textarea observer set up');
  240. 		return true;
  241. 	}
  242.  
  243. 	/**
  244. 	 * Handles page navigation changes, activating or deactivating MDC rendering based on URL
  245. 	 */
  246. 	function handlePageChange() {
  247. 		if (MDC_FILE_REGEX.test(location.href)) {
  248. 			if (!isActive) {
  249. 				DEBUG && console.log('[mdc-lite] MDC file detected:', location.href);
  250. 				isActive = true;
  251.  
  252. 				if (renderMDC()) {
  253. 					setupTextareaObserver();
  254. 				} else {
  255. 					// Content not ready yet - retry with exponential backoff would be better, but keeping simple
  256. 					let attempts = 0;
  257.  
  258. 					const interval = setInterval(() => {
  259. 						attempts++;
  260. 						if (renderMDC()) {
  261. 							clearInterval(interval);
  262. 							setupTextareaObserver();
  263. 						} else if (attempts >= MAX_RENDER_ATTEMPTS) {
  264. 							clearInterval(interval);
  265. 							DEBUG && console.log('[mdc-lite] Timeout waiting for content');
  266. 						}
  267. 					}, RENDER_RETRY_INTERVAL);
  268. 				}
  269. 			} else {
  270. 				// SPA navigation to another MDC file - re-render to sync toggle state
  271. 				if (renderMDC()) {
  272. 					setupTextareaObserver();
  273. 				}
  274. 			}
  275. 		} else if (isActive) {
  276. 			cleanup();
  277. 		}
  278. 	}
  279.  
  280. 	/**
  281. 	 * Initializes the userscript by setting up page change detection and handling the current page
  282. 	 */
  283. 	function init() {
  284. 		handlePageChange();
  285.  
  286. 		// Monitor for SPA navigation changes
  287. 		new MutationObserver(() => {
  288. 			if (location.href !== currentUrl) {
  289. 				currentUrl = location.href;
  290. 				DEBUG && console.log('[mdc-lite] Navigation detected:', currentUrl);
  291. 				handlePageChange();
  292. 			}
  293. 		}).observe(document, { subtree: true, childList: true });
  294.  
  295. 		DEBUG && console.log('[mdc-lite] Initialized');
  296. 	}
  297.  
  298. 	if (document.readyState === 'loading') {
  299. 		document.addEventListener('DOMContentLoaded', init);
  300. 	} else {
  301. 		init();
  302. 	}
  303.  
  304. })();