refactor(embed): async fetch embed files, fixed #387

src/core/render/embed.js

@@ -0,0 +1,84 @@
+import { get } from '../fetch/ajax'
+import { merge } from '../util/core'
+
+const cached = {}
+
+function walkFetchEmbed ({ step = 0, embedTokens, compile }, cb) {
+  const token = embedTokens[step]
+
+  if (!token) {
+    return cb({})
+  }
+
+  get(token.embed.url).then(text => {
+    let embedToken
+
+    if (token.embed.type === 'markdown') {
+      embedToken = compile.lexer(text)
+    } else if (token.embed.type === 'code') {
+      embedToken = compile.lexer(
+        '```' +
+          token.embed.lang +
+          '\n' +
+          text.replace(/`/g, '@DOCSIFY_QM@') +
+          '\n```\n'
+      )
+    }
+    cb({ token, embedToken })
+    walkFetchEmbed({ step: ++step, compile, embedTokens }, cb)
+  })
+}
+
+export function prerenderEmbed ({ compiler, raw }, done) {
+  let hit
+  if ((hit = cached[raw])) {
+    return done(hit)
+  }
+
+  const compile = compiler._marked
+  let tokens = compile.lexer(raw)
+  const embedTokens = []
+  const linkRE = compile.InlineLexer.rules.link
+  const links = tokens.links
+
+  tokens.forEach((token, index) => {
+    if (token.type === 'paragraph') {
+      token.text = token.text.replace(
+        new RegExp(linkRE, 'g'),
+        (src, filename, href, title) => {
+          const embed = compiler.compileEmbed(href, title)
+
+          if (embed) {
+            if (embed.type === 'markdown' || embed.type === 'code') {
+              embedTokens.push({
+                index,
+                embed
+              })
+            }
+            return embed.code
+          }
+
+          return src
+        }
+      )
+    }
+  })
+
+  let moveIndex = 0
+  walkFetchEmbed({ compile, embedTokens }, ({ embedToken, token }) => {
+    if (token) {
+      const index = token.index + moveIndex
+
+      merge(links, embedToken.links)
+
+      tokens = tokens
+        .slice(0, index)
+        .concat(embedToken, tokens.slice(index + 1))
+      moveIndex += embedToken.length - 1
+    } else {
+      cached[raw] = tokens.concat()
+      tokens.links = cached[raw].links = links
+      done(tokens)
+    }
+  })
+}