refactor: split vdom helpers into separate files

Author: yyx990803

src/core/components/keep-alive.js

@@ -1,5 +1,5 @@
 import { callHook } from 'core/instance/lifecycle'
-import { getFirstComponentChild } from 'core/vdom/helpers'
+import { getFirstComponentChild } from 'core/vdom/helpers/index'
 
 export default {
   name: 'keep-alive',

src/core/instance/events.js

@@ -1,7 +1,7 @@
 /* @flow */
 
 import { bind, toArray } from '../util/index'
-import { updateListeners } from '../vdom/helpers'
+import { updateListeners } from '../vdom/helpers/index'
 
 export function initEvents (vm: Component) {
   vm._events = Object.create(null)

src/core/instance/render.js

@@ -2,7 +2,7 @@
 
 import config from '../config'
 import VNode, { emptyVNode, cloneVNode, cloneVNodes } from '../vdom/vnode'
-import { normalizeChildren } from '../vdom/helpers'
+import { normalizeChildren } from '../vdom/helpers/index'
 import {
   warn, formatComponentName, bind, isObject, toObject,
   nextTick, resolveAsset, _toString, toNumber, looseEqual, looseIndexOf

src/core/vdom/create-component.js

@@ -2,7 +2,7 @@
 
 import Vue from '../instance/index'
 import VNode from './vnode'
-import { normalizeChildren } from './helpers'
+import { normalizeChildren } from './helpers/index'
 import { activeInstance, callHook } from '../instance/lifecycle'
 import { resolveSlots } from '../instance/render'
 import { createElement } from './create-element'

src/core/vdom/create-element.js

@@ -3,7 +3,7 @@
 import VNode, { emptyVNode } from './vnode'
 import config from '../config'
 import { createComponent } from './create-component'
-import { normalizeChildren } from './helpers'
+import { normalizeChildren } from './helpers/index'
 import { warn, resolveAsset } from '../util/index'
 
 // wrapper function for providing a more flexible interface

src/core/vdom/helpers.js

@@ -0,0 +1,9 @@
+/* @flow */
+
+export * from './merge-hook'
+export * from './update-listeners'
+export * from './normalize-children'
+
+export function getFirstComponentChild (children: ?Array<any>): ?VNodeWithData {
+  return children && children.filter(c => c && c.componentOptions)[0]
+}

src/core/vdom/helpers/index.js

@@ -0,0 +1,18 @@
+/* @flow */
+
+export function mergeVNodeHook (def: Object, hookKey: string, hook: Function, key: string) {
+  key = key + hookKey
+  const injectedHash = def.__injected || (def.__injected = {})
+  if (!injectedHash[key]) {
+    injectedHash[key] = true
+    const oldHook = def[hookKey]
+    if (oldHook) {
+      def[hookKey] = function () {
+        oldHook.apply(this, arguments)
+        hook.apply(this, arguments)
+      }
+    } else {
+      def[hookKey] = hook
+    }
+  }
+}

src/core/vdom/helpers/merge-hook.js

@@ -0,0 +1,62 @@
+/* @flow */
+
+import { isPrimitive } from 'core/util/index'
+import VNode from 'core/vdom/vnode'
+
+export function normalizeChildren (
+  children: any,
+  ns: string | void,
+  nestedIndex: number | void
+): Array<VNode> | void {
+  if (isPrimitive(children)) {
+    return [createTextVNode(children)]
+  }
+  if (Array.isArray(children)) {
+    const res = []
+    for (let i = 0, l = children.length; i < l; i++) {
+      const c = children[i]
+      const last = res[res.length - 1]
+      //  nested
+      if (Array.isArray(c)) {
+        res.push.apply(res, normalizeChildren(c, ns, i))
+      } else if (isPrimitive(c)) {
+        if (last && last.text) {
+          last.text += String(c)
+        } else if (c !== '') {
+          // convert primitive to vnode
+          res.push(createTextVNode(c))
+        }
+      } else if (c instanceof VNode) {
+        if (c.text && last && last.text) {
+          last.text += c.text
+        } else {
+          // inherit parent namespace
+          if (ns) {
+            applyNS(c, ns)
+          }
+          // default key for nested array children (likely generated by v-for)
+          if (c.tag && c.key == null && nestedIndex != null) {
+            c.key = `__vlist_${nestedIndex}_${i}__`
+          }
+          res.push(c)
+        }
+      }
+    }
+    return res
+  }
+}
+
+function createTextVNode (val) {
+  return new VNode(undefined, undefined, undefined, String(val))
+}
+
+function applyNS (vnode, ns) {
+  if (vnode.tag && !vnode.ns) {
+    vnode.ns = ns
+    if (vnode.children) {
+      for (let i = 0, l = vnode.children.length; i < l; i++) {
+        applyNS(vnode.children[i], ns)
+      }
+    }
+  }
+}

src/core/vdom/helpers/normalize-children.js

@@ -0,0 +1,68 @@
+/* @flow */
+
+import { warn } from 'core/util/index'
+
+export function updateListeners (
+  on: Object,
+  oldOn: Object,
+  add: Function,
+  remove: Function,
+  vm: Component
+) {
+  let name, cur, old, fn, event, capture
+  for (name in on) {
+    cur = on[name]
+    old = oldOn[name]
+    if (!cur) {
+      process.env.NODE_ENV !== 'production' && warn(
+        `Invalid handler for event "${name}": got ` + String(cur),
+        vm
+      )
+    } else if (!old) {
+      capture = name.charAt(0) === '!'
+      event = capture ? name.slice(1) : name
+      if (Array.isArray(cur)) {
+        add(event, (cur.invoker = arrInvoker(cur)), capture)
+      } else {
+        if (!cur.invoker) {
+          fn = cur
+          cur = on[name] = {}
+          cur.fn = fn
+          cur.invoker = fnInvoker(cur)
+        }
+        add(event, cur.invoker, capture)
+      }
+    } else if (cur !== old) {
+      if (Array.isArray(old)) {
+        old.length = cur.length
+        for (let i = 0; i < old.length; i++) old[i] = cur[i]
+        on[name] = old
+      } else {
+        old.fn = cur
+        on[name] = old
+      }
+    }
+  }
+  for (name in oldOn) {
+    if (!on[name]) {
+      event = name.charAt(0) === '!' ? name.slice(1) : name
+      remove(event, oldOn[name].invoker)
+    }
+  }
+}
+
+function arrInvoker (arr: Array<Function>): Function {
+  return function (ev) {
+    const single = arguments.length === 1
+    for (let i = 0; i < arr.length; i++) {
+      single ? arr[i](ev) : arr[i].apply(null, arguments)
+    }
+  }
+}
+
+function fnInvoker (o: { fn: Function }): Function {
+  return function (ev) {
+    const single = arguments.length === 1
+    single ? o.fn(ev) : o.fn.apply(null, arguments)
+  }
+}