adjust route component instance registration strategy (fix #1286)

Author: yyx990803

src/components/view.js

@@ -45,17 +45,12 @@ export default {
 
     const component = cache[name] = matched.components[name]
 
-    // inject instance registration hooks
-    const hooks = data.hook || (data.hook = {})
-    hooks.init = vnode => {
-      matched.instances[name] = vnode.componentInstance
-    }
-    hooks.prepatch = (oldVnode, vnode) => {
-      matched.instances[name] = vnode.componentInstance
-    }
-    hooks.destroy = vnode => {
-      if (matched.instances[name] === vnode.componentInstance) {
-        matched.instances[name] = undefined
+    // attach instance registration hook
+    // this will be called in the instance's injected lifecycle hooks
+    data.registerRouteInstance = (vm, val) => {
+      // val could be undefined for unregistration
+      if (matched.instances[name] !== vm) {
+        matched.instances[name] = val
       }
     }
 

src/install.js

@@ -17,13 +17,26 @@ export function install (Vue) {
     get () { return this.$root._route }
   })
 
+  const isDef = v => v !== undefined
+
+  const registerInstance = (vm, callVal) => {
+    let i = vm.$options._parentVnode
+    if (isDef(i) && isDef(i = i.data) && isDef(i = i.registerRouteInstance)) {
+      i(vm, callVal)
+    }
+  }
+
   Vue.mixin({
     beforeCreate () {
-      if (this.$options.router) {
+      if (isDef(this.$options.router)) {
         this._router = this.$options.router
         this._router.init(this)
         Vue.util.defineReactive(this, '_route', this._router.history.current)
       }
+      registerInstance(this, this)
+    },
+    destroyed () {
+      registerInstance(this)
     }
   })