Support brace wrapped param in fence lang

Signed-off-by: Yukai Huang <yukaihuangtw@gmail.com>

public/js/extra.js

@@ -15,6 +15,7 @@ import { stripTags } from '../../utils/string'
 
 import getUIElements from './lib/editor/ui-elements'
 import { emojifyImageDir } from './lib/editor/constants'
+import { parseFenceCodeParams, serializeParamToAttribute } from './lib/markdown/utils'
 
 import markdownit from 'markdown-it'
 import markdownitContainer from 'markdown-it-container'
@@ -1028,24 +1029,30 @@ export function scrollToHash () {
   location.hash = hash
 }
 
+const fenceCodeAlias = {
+  sequence: 'sequence-diagram',
+  flow: 'flow-chart',
+  graphviz: 'graphviz',
+  mermaid: 'mermaid',
+  abc: 'abc',
+  vega: 'vega',
+  geo: 'geo'
+}
+
 function highlightRender (code, lang) {
   if (!lang || /no(-?)highlight|plain|text/.test(lang)) { return }
+
+  const params = parseFenceCodeParams(lang)
+  const attr = serializeParamToAttribute(params)
+  lang = lang.split(/\s+/g)[0]
+
   code = escapeHTML(code)
-  if (lang === 'sequence') {
-    return `<div class="sequence-diagram raw">${code}</div>`
-  } else if (lang === 'flow') {
-    return `<div class="flow-chart raw">${code}</div>`
-  } else if (lang === 'graphviz') {
-    return `<div class="graphviz raw">${code}</div>`
-  } else if (lang === 'mermaid') {
-    return `<div class="mermaid raw">${code}</div>`
-  } else if (lang === 'abc') {
-    return `<div class="abc raw">${code}</div>`
-  } else if (lang === 'vega') {
-    return `<div class="vega raw">${code}</div>`
-  } else if (lang === 'geo') {
-    return `<div class="geo raw">${code}</div>`
+
+  const langAlias = fenceCodeAlias[lang]
+  if (langAlias) {
+    return `<div class="${langAlias} raw"${attr}>${code}</div>`
   }
+
   const result = {
     value: code
   }
@@ -1167,7 +1174,7 @@ md.renderer.rules.fence = (tokens, idx, options, env, self) => {
   }
 
   if (options.highlight) {
-    highlighted = options.highlight(token.content, langName) || md.utils.escapeHtml(token.content)
+    highlighted = options.highlight(token.content, info) || md.utils.escapeHtml(token.content)
   } else {
     highlighted = md.utils.escapeHtml(token.content)
   }

public/js/lib/markdown/utils.js

@@ -0,0 +1,53 @@
+export function parseFenceCodeParams (lang) {
+  const attrMatch = lang.match(/{(.*)}/)
+  const params = {}
+  if (attrMatch && attrMatch.length >= 2) {
+    const attrs = attrMatch[1]
+    const paraMatch = attrs.match(/([#.](\S+?)\s)|((\S+?)\s*=\s*("(.+?)"|'(.+?)'|\[[^\]]*\]|\{[}]*\}|(\S+)))/g)
+    paraMatch && paraMatch.forEach(param => {
+      param = param.trim()
+      if (param[0] === '#') {
+        params['id'] = param.slice(1)
+      } else if (param[0] === '.') {
+        if (params['class']) params['class'] = []
+        params['class'] = params['class'].concat(param.slice(1))
+      } else {
+        const offset = param.indexOf('=')
+        const id = param.substring(0, offset).trim().toLowerCase()
+        let val = param.substring(offset + 1).trim()
+        const valStart = val[0]
+        const valEnd = val[val.length - 1]
+        if (['"', "'"].indexOf(valStart) !== -1 && ['"', "'"].indexOf(valEnd) !== -1 && valStart === valEnd) {
+          val = val.substring(1, val.length - 1)
+        }
+        if (id === 'class') {
+          if (params['class']) params['class'] = []
+          params['class'] = params['class'].concat(val)
+        } else {
+          params[id] = val
+        }
+      }
+    })
+  }
+  return params
+}
+
+export function serializeParamToAttribute (params) {
+  if (Object.getOwnPropertyNames(params).length === 0) {
+    return ''
+  } else {
+    return ` data-params="${escape(JSON.stringify(params))}"`
+  }
+}
+
+/**
+ * @param {HTMLElement} elem
+ */
+export function deserializeParamAttributeFromElement (elem) {
+  const params = elem.getAttribute('data-params')
+  if (params) {
+    return JSON.parse(unescape(params))
+  } else {
+    return {}
+  }
+}

public/js/lib/syncscroll.js

@@ -73,7 +73,7 @@ md.renderer.rules.fence = (tokens, idx, options, env, self) => {
   }
 
   if (options.highlight) {
-    highlighted = options.highlight(token.content, langName) || md.utils.escapeHtml(token.content)
+    highlighted = options.highlight(token.content, info) || md.utils.escapeHtml(token.content)
   } else {
     highlighted = md.utils.escapeHtml(token.content)
   }