* [jsfm] fix callback

src/js-framework/lib/app/__test__/ctrl.js

@@ -126,20 +126,20 @@ describe('the api of app', () => {
   describe('callback', () => {
     it('with a simple data', () => {
       const data = {a: 'b'}
-      app.callback('1', data, false)
+      app.callback('1', data, true)
       expect(spy2.calledOnce).to.be.true
       expect(spy2.args[0][0]).to.deep.equal(data)
       expect(app.callbacks[1]).to.be.a('function')
     })
 
     it('multiple called', () => {
       const data = {a: 'b'}
-      app.callback('1', data, false)
+      app.callback('1', data, true)
       expect(spy2.calledTwice).to.be.true
       expect(spy2.args[0][0]).to.deep.equal(data)
       expect(app.callbacks[1]).to.be.a('function')
 
-      app.callback('1', data, true)
+      app.callback('1', data, false)
       expect(spy2.calledThrice).to.be.true
       expect(spy2.args[0][0]).to.deep.equal(data)
       expect(app.callbacks[1]).to.be.undefined

src/js-framework/lib/app/ctrl.js

@@ -127,13 +127,13 @@ export function fireEvent(ref, type, e, domChanges) {
   return new Error(`invalid element reference "${ref}"`)
 }
 
-export function callback(callbackId, data, ifLast) {
+export function callback(callbackId, data, ifKeepAlive) {
   const callback = this.callbacks[callbackId]
 
   if (typeof callback === 'function') {
     callback(data) // data is already a object, @see: lib/framework.js
 
-    if (typeof ifLast === 'undefined' || ifLast === true) {
+    if (typeof ifKeepAlive === 'undefined' || ifKeepAlive === false) {
       this.callbacks[callbackId] = undefined
     }