update weex events module

Author: yyx990803

src/platforms/weex/runtime/modules/events.js

@@ -2,21 +2,50 @@
 
 import { updateListeners } from 'core/vdom/helpers/update-listeners'
 
+let target: any
+
+function add (
+  event: string,
+  handler: Function,
+  once: boolean,
+  capture: boolean
+) {
+  if (capture) {
+    console.log('Weex do not support event in bubble phase.')
+    return
+  }
+  if (once) {
+    const oldHandler = handler
+    const _target = target // save current target element in closure
+    handler = function (ev) {
+      const res = arguments.length === 1
+        ? oldHandler(ev)
+        : oldHandler.apply(null, arguments)
+      if (res !== null) {
+        remove(event, null, null, _target)
+      }
+    }
+  }
+  target.addEvent(event, handler)
+}
+
+function remove (
+  event: string,
+  handler: any,
+  capture: any,
+  _target?: any
+) {
+  (_target || target).removeEvent(event)
+}
+
 function updateDOMListeners (oldVnode: VNodeWithData, vnode: VNodeWithData) {
   if (!oldVnode.data.on && !vnode.data.on) {
     return
   }
   const on = vnode.data.on || {}
   const oldOn = oldVnode.data.on || {}
-  updateListeners(on, oldOn, (event, handler, capture) => {
-    if (capture) {
-      console.log('Weex do not support event in bubble phase.')
-      return
-    }
-    vnode.elm.addEvent(event, handler.bind(vnode.context))
-  }, (event) => {
-    vnode.elm.removeEvent(event)
-  }, vnode.context)
+  target = vnode.elm
+  updateListeners(on, oldOn, add, remove, vnode.context)
 }
 
 export default {