Backbone.js的 - 更改事件不触发 [英] Backbone.js - change event not firing

问题描述

<div class='container'></div>

<script>
// Define models.  View is a div with a counter.
Tasks = Backbone.Collection.extend({localStorage: new Store("tasks")})
Tasks = new Tasks
Tasks.bind('add', function (task_model) {
  task_model.bind('change', function(){ render(this) })
  $('.container').append(render(task_model))
})

function render(model) {
  console.log('rendering, daily_times: ', model.get('daily_times'))
  var div = '<div class="current task_time" task_id="%id">%time</div>'
  var time_str = model.get('daily_times')['Jun 28 2011']
  div = div.replace('%id', model.id).replace('%time', time_str)
  $('div[task_id="%id"]'.replace('%id', model.id)).replaceWith(div)
  return div
}

// Start pinging
setInterval(ping, 1000)
Tasks.create({daily_times:{'Jun 28 2011':0}})
function ping() { 
  console.log('ping')
  Tasks.each(function(task) {
    var times = task.get('daily_times')
    times['Jun 28 2011'] += 1
    task.set({daily_times:times})
    console.log('incremented, time: ', task.get('daily_times')['Jun 28 2011'])
  })
}
</script>

为什么没有改变事件防火当我设置 daily_times 在平？

推荐答案

看起来 VAR次是一个对象，而不是一个值。因此，当它使用_.toEqual方法，看看新的值是相同的旧值，其实际的对象进行比较，以本身和返回true，所以主链决定没有必要以触发改变事件

It looks like var times is an object rather than a value. So when it uses the _.toEqual method to see if the new value is the same as the old value, its actually comparing the object to itself and returns true, so backbone decides there is no need to fire the change event.

您可以用task.change（）显式地触发change事件。

You can fire the change event explicitly with task.change().

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