refactor highlight: add extend api for highlight

lib/extend/filter.js

@@ -55,6 +55,11 @@ class Filter {
     if (index !== -1) list.splice(index, 1);
   }
 
+  queryCount(type) {
+    const filters = this.list(type);
+    return filters.length;
+  }
+
   exec(type, data, options = {}) {
     const filters = this.list(type);
     if (filters.length === 0) return Promise.resolve(data);
@@ -87,6 +92,22 @@ class Filter {
 
     return args[0];
   }
+
+  execFirstSync(type, data, options = {}) {
+    const filters = this.list(type);
+    const filtersLen = filters.length;
+    if (filtersLen === 0) return null;
+
+    const ctx = options.context;
+    const args = options.args || [];
+
+    args.unshift(data);
+
+    const result = Reflect.apply(filters[0], ctx, args);
+    args[0] = result == null ? args[0] : result;
+
+    return args[0];
+  }
 }
 
 module.exports = Filter;

lib/hexo/index.js

@@ -240,7 +240,8 @@ class Hexo extends EventEmitter {
       'update_package', // Update package.json
       'load_config', // Load config
       'load_theme_config', // Load alternate theme config
-      'load_plugins' // Load external plugins & scripts
+      'load_plugins', // Load external plugins & scripts
+      'load_highlight' // Load highlight.js or prism.js
     ], name => require(`./${name}`)(this)).then(() => this.execFilter('after_init', null, { context: this })).then(() => {
       // Ready to go!
       this.emit('ready');
@@ -478,13 +479,21 @@ class Hexo extends EventEmitter {
     });
   }
 
+  queryFilterCount(type) {
+    return this.extend.filter.queryCount(type);
+  }
+
   execFilter(type, data, options) {
     return this.extend.filter.exec(type, data, options);
   }
 
   execFilterSync(type, data, options) {
     return this.extend.filter.execSync(type, data, options);
   }
+
+  execFirstFilterSync(type, data, options) {
+    return this.extend.filter.execFirstSync(type, data, options);
+  }
 }
 
 Hexo.lib_dir = libDir + sep;

lib/hexo/load_highlight.js

@@ -0,0 +1,3 @@
+'use strict';
+
+module.exports = require('../plugins/filter/highlight');

lib/plugins/filter/before_post_render/backtick_code_block.js

@@ -1,111 +1,70 @@
 'use strict';
 
-let highlight, prismHighlight;
-
 const rBacktick = /^((?:[^\S\r\n]*>){0,3}[^\S\r\n]*)(`{3,}|~{3,})[^\S\r\n]*((?:.*?[^`\s])?)[^\S\r\n]*\n((?:[\s\S]*?\n)?)(?:(?:[^\S\r\n]*>){0,3}[^\S\r\n]*)\2[^\S\r\n]?(\n+|$)/gm;
 const rAllOptions = /([^\s]+)\s+(.+?)\s+(https?:\/\/\S+|\/\S+)\s*(.+)?/;
 const rLangCaption = /([^\s]+)\s*(.+)?/;
 
 const escapeSwigTag = str => str.replace(/{/g, '{').replace(/}/g, '}');
 
-function backtickCodeBlock(data) {
-  const dataContent = data.content;
-
-  const hljsCfg = this.config.highlight || {};
-  const prismCfg = this.config.prismjs || {};
+module.exports = ctx => {
+  return function backtickCodeBlock(data) {
+    const dataContent = data.content;
 
-  if ((!dataContent.includes('```') && !dataContent.includes('~~~')) || (!hljsCfg.enable && !prismCfg.enable)) return;
+    if ((!dataContent.includes('```') && !dataContent.includes('~~~')) || !ctx.queryFilterCount('highlight')) return;
 
-  data.content = dataContent.replace(rBacktick, ($0, start, $2, _args, _content, end) => {
-    let content = _content.replace(/\n$/, '');
+    data.content = dataContent.replace(rBacktick, ($0, start, $2, _args, _content, end) => {
+      let content = _content.replace(/\n$/, '');
 
-    // neither highlight or prismjs is enabled, return escaped content directly.
-    if (!hljsCfg.enable && !prismCfg.enable) return escapeSwigTag($0);
+      // neither highlight or prismjs is enabled, return escaped content directly.
+      if (!ctx.queryFilterCount('highlight')) return escapeSwigTag($0);
 
-    // Extract language and caption of code blocks
-    const args = _args.split('=').shift();
-    let lang, caption;
+      // Extract language and caption of code blocks
+      const args = _args.split('=').shift();
+      let lang, caption;
 
-    if (args) {
-      const match = rAllOptions.exec(args) || rLangCaption.exec(args);
+      if (args) {
+        const match = rAllOptions.exec(args) || rLangCaption.exec(args);
 
-      if (match) {
-        lang = match[1];
+        if (match) {
+          lang = match[1];
 
-        if (match[2]) {
-          caption = `<span>${match[2]}</span>`;
+          if (match[2]) {
+            caption = `<span>${match[2]}</span>`;
 
-          if (match[3]) {
-            caption += `<a href="${match[3]}">${match[4] ? match[4] : 'link'}</a>`;
+            if (match[3]) {
+              caption += `<a href="${match[3]}">${match[4] ? match[4] : 'link'}</a>`;
+            }
           }
         }
       }
-    }
-
-    // PR #3765
-    if (start.includes('>')) {
-      // heading of last line is already removed by the top RegExp "rBacktick"
-      const depth = start.split('>').length - 1;
-      const regexp = new RegExp(`^([^\\S\\r\\n]*>){0,${depth}}([^\\S\\r\\n]|$)`, 'mg');
-      content = content.replace(regexp, '');
-    }
 
-    // Since prismjs have better performance, so prismjs should have higher priority.
-    if (prismCfg.enable) {
-      if (!prismHighlight) prismHighlight = require('hexo-util').prismHighlight;
-
-      const options = {
-        lineNumber: prismCfg.line_number,
-        tab: prismCfg.tab_replace,
-        isPreprocess: prismCfg.preprocess,
-        lang,
-        caption
-      };
-
-      content = prismHighlight(content, options);
-    } else if (hljsCfg.enable) {
-      if (!highlight) highlight = require('hexo-util').highlight;
+      // PR #3765
+      if (start.includes('>')) {
+        // heading of last line is already removed by the top RegExp "rBacktick"
+        const depth = start.split('>').length - 1;
+        const regexp = new RegExp(`^([^\\S\\r\\n]*>){0,${depth}}([^\\S\\r\\n]|$)`, 'mg');
+        content = content.replace(regexp, '');
+      }
 
       const options = {
-        hljs: hljsCfg.hljs,
-        autoDetect: hljsCfg.auto_detect,
-        gutter: hljsCfg.line_number,
-        tab: hljsCfg.tab_replace,
-        wrap: hljsCfg.wrap,
         lang,
-        languageAttr: hljsCfg.language_attr,
-        caption
+        caption,
+        lines_length: content.split('\n').length
       };
+      // setup line number by inline
+      _args = _args.replace('=+', '=');
 
-      if (options.gutter) {
-        hljsCfg.first_line_number = hljsCfg.first_line_number || 'always1';
-        if (hljsCfg.first_line_number === 'inline') {
-
-          // setup line number by inline
-          _args = _args.replace('=+', '=');
-          options.gutter = _args.includes('=');
-
-          // setup firstLineNumber;
-          options.firstLine = options.gutter ? _args.split('=')[1] || 1 : 0;
-        }
-      }
-
-      if (Array.isArray(hljsCfg.exclude_languages) && hljsCfg.exclude_languages.includes(options.lang)) {
-        // Only wrap with <pre><code class="lang"></code></pre>
-        options.wrap = false;
-        options.gutter = false;
-        options.autoDetect = false;
+      // setup firstLineNumber;
+      if (_args.includes('=')) {
+        options.firstLineNumber = _args.split('=')[1] || 1;
       }
-
-      content = highlight(content, options);
-    }
-
-    return start
-      + '<hexoPostRenderCodeBlock>'
-      + escapeSwigTag(content)
-      + '</hexoPostRenderCodeBlock>'
-      + end;
-  });
-}
-
-module.exports = backtickCodeBlock;
+      content = ctx.execFirstFilterSync('highlight', content, { args: [options] });
+
+      return start
+        + '<hexoPostRenderCodeBlock>'
+        + escapeSwigTag(content)
+        + '</hexoPostRenderCodeBlock>'
+        + end;
+    });
+  };
+};

lib/plugins/filter/before_post_render/index.js

@@ -3,6 +3,6 @@
 module.exports = ctx => {
   const { filter } = ctx.extend;
 
-  filter.register('before_post_render', require('./backtick_code_block'));
+  filter.register('before_post_render', require('./backtick_code_block')(ctx));
   filter.register('before_post_render', require('./titlecase'));
 };

lib/plugins/filter/highlight/highlight.js

@@ -0,0 +1,46 @@
+'use strict';
+
+// Lazy require highlight.js
+let highlight;
+
+module.exports = ctx => {
+  return function highlightFilter(code, options) {
+    const hljsCfg = ctx.config.highlight || {};
+    const line_threshold = options.line_threshold || hljsCfg.line_threshold || 0;
+    const shouldUseLineNumbers = typeof options.line_number === 'undefined' ? hljsCfg.line_number : options.line_number;
+    const surpassesLineThreshold = options.lines_length > line_threshold;
+    const gutter = shouldUseLineNumbers && surpassesLineThreshold;
+    const languageAttr = typeof options.language_attr === 'undefined' ? hljsCfg.language_attr : options.language_attr;
+
+    const hljsOptions = {
+      autoDetect: hljsCfg.auto_detect,
+      caption: options.caption,
+      firstLine: options.firstLine,
+      gutter,
+      hljs: hljsCfg.hljs,
+      lang: options.lang,
+      languageAttr,
+      mark: options.mark,
+      tab: hljsCfg.tab_replace,
+      wrap: hljsCfg.wrap
+    };
+    if (hljsCfg.first_line_number === 'inline') {
+      if (typeof options.firstLineNumber !== 'undefined') {
+        hljsOptions.firstLine = options.firstLineNumber;
+      } else {
+        hljsOptions.gutter = false;
+      }
+    }
+
+    if (Array.isArray(hljsCfg.exclude_languages) && hljsCfg.exclude_languages.includes(hljsOptions.lang)) {
+      // Only wrap with <pre><code class="lang"></code></pre>
+      hljsOptions.wrap = false;
+      hljsOptions.gutter = false;
+      hljsOptions.autoDetect = false;
+    }
+
+    if (!highlight) highlight = require('hexo-util').highlight;
+
+    return highlight(code, hljsOptions);
+  };
+};

lib/plugins/filter/highlight/index.js

@@ -0,0 +1,14 @@
+'use strict';
+
+module.exports = ctx => {
+  const { filter } = ctx.extend;
+  const hljsCfg = ctx.config.highlight || {};
+  const prismCfg = ctx.config.prismjs || {};
+
+  // Since prismjs have better performance, so prismjs should have higher priority.
+  if (prismCfg.enable) {
+    filter.register('highlight', require('./prism')(ctx));
+  } else if (hljsCfg.enable) {
+    filter.register('highlight', require('./highlight')(ctx));
+  }
+};

lib/plugins/filter/highlight/prism.js

@@ -0,0 +1,28 @@
+'use strict';
+
+// Lazy require prismjs
+let prismHighlight;
+
+module.exports = ctx => {
+  return function(code, options) {
+    const prismjsCfg = ctx.config.prismjs || {};
+    const line_threshold = options.line_threshold || prismjsCfg.line_threshold || 0;
+    const shouldUseLineNumbers = typeof options.line_number === 'undefined' ? prismjsCfg.line_number : options.line_number;
+    const surpassesLineThreshold = options.lines_length > line_threshold;
+    const lineNumber = shouldUseLineNumbers && surpassesLineThreshold;
+
+    const prismjsOptions = {
+      caption: options.caption,
+      firstLine: options.firstLine,
+      isPreprocess: prismjsCfg.preprocess,
+      lang: options.lang,
+      lineNumber,
+      mark: options.mark,
+      tab: prismjsCfg.tab_replace
+    };
+
+    if (!prismHighlight) prismHighlight = require('hexo-util').prismHighlight;
+
+    return prismHighlight(code, prismjsOptions);
+  };
+};

lib/plugins/filter/index.js

@@ -9,6 +9,7 @@ module.exports = ctx => {
   require('./before_exit')(ctx);
   require('./before_generate')(ctx);
   require('./template_locals')(ctx);
+  require('./highlight')(ctx);
 
   filter.register('new_post_path', require('./new_post_path'));
   filter.register('post_permalink', require('./post_permalink'));