feat($markdown): support pass in block data at compile time

Author: ulivz

packages/@vuepress/markdown-loader/index.js

@@ -66,7 +66,7 @@ module.exports = function (src) {
 
   // the render method has been augmented to allow plugins to
   // register data during render
-  const { html, data: { hoistedTags, links }} = markdown.render(content)
+  const { html, data: { hoistedTags, links }, dataBlockString } = markdown.render(content)
 
   // check if relative links are valid
   links && links.forEach(link => {
@@ -102,7 +102,8 @@ module.exports = function (src) {
     `<template>\n` +
       `<div class="content">${html}</div>\n` +
     `</template>\n` +
-    (hoistedTags || []).join('\n')
+    (hoistedTags || []).join('\n') +
+    `\n${dataBlockString}\n`
   )
   cache.set(key, res)
   return res

packages/@vuepress/markdown/lib/hoist.js

@@ -3,7 +3,7 @@ module.exports = md => {
 
   md.renderer.rules.html_block = (tokens, idx) => {
     const content = tokens[idx].content
-    const hoistedTags = md.__data.hoistedTags || (md.__data.hoistedTags = [])
+    const hoistedTags = md.$data.hoistedTags || (md.$data.hoistedTags = [])
     if (RE.test(content.trim())) {
       hoistedTags.push(content)
       return ''

packages/@vuepress/markdown/lib/index.js

@@ -121,11 +121,21 @@ module.exports.dataReturnable = function dataReturnable (md) {
   // override render to allow custom plugins return data
   const render = md.render
   md.render = (...args) => {
-    md.__data = {}
+    md.$data = {}
+    md.$data.__data_block = {}
+    md.$dataBlock = md.$data.__data_block
     const html = render.call(md, ...args)
     return {
       html,
-      data: md.__data
+      data: md.$data,
+      dataBlockString: toDataBlockString(md.$dataBlock)
     }
   }
 }
+
+function toDataBlockString (ob) {
+  if (Object.keys(ob).length === 0) {
+    return ''
+  }
+  return `<data>${JSON.stringify(ob)}</data>`
+}

packages/@vuepress/markdown/lib/link.js

@@ -36,7 +36,7 @@ module.exports = (md, externalAttrs) => {
     let to = link[1]
 
     // convert link to filename and export it for existence check
-    const links = md.__data.links || (md.__data.links = [])
+    const links = md.$data.links || (md.$data.links = [])
     links.push(to)
 
     const indexMatch = to.match(indexRE)
@@ -58,7 +58,7 @@ module.exports = (md, externalAttrs) => {
     link[1] = decodeURI(to)
 
     // export the router links for testing
-    const routerLinks = md.__data.routerLinks || (md.__data.routerLinks = [])
+    const routerLinks = md.$data.routerLinks || (md.$data.routerLinks = [])
     routerLinks.push(to)
 
     return Object.assign({}, token, {