refactor(core): add router

src/core/fetch/index.js

@@ -1,13 +1,43 @@
+import { get } from './ajax'
 import { callHook } from '../init/lifecycle'
+import { getCurrentRoot } from '../route/util'
 
 export function fetchMixin (Docsify) {
-  Docsify.prototype.$fetch = function (path) {
-    // 加载侧边栏、导航、内容
+  let last
+
+  Docsify.prototype._fetch = function (cb) {
+    const { path } = this.route
+    const { loadNavbar, loadSidebar } = this.config
+    const currentRoot = getCurrentRoot(path)
+
+    // Abort last request
+    last && last.abort && last.abort()
+
+    last = get(this.$getFile(path), true)
+    last.then(text => {
+      this._renderMain(text)
+      if (!loadSidebar) return cb()
+
+      const fn = result => { this._renderSidebar(result); cb() }
+
+      // Load sidebar
+      get(this.$getFile(currentRoot + loadSidebar))
+        .then(fn, _ => get(loadSidebar).then(fn))
+    },
+    _ => this._renderMain(null))
+
+    // Load nav
+    loadNavbar &&
+    get(this.$getFile(currentRoot + loadNavbar))
+      .then(
+        this._renderNav,
+        _ => get(loadNavbar).then(this._renderNav)
+      )
   }
 }
 
 export function initFetch (vm) {
-  vm.$fetch(result => {
+  vm._fetch(result => {
     vm.$resetEvents()
     callHook(vm, 'doneEach')
   })