主干中的模型更改渲染

Question

Most Backbone tutorials and examples I've come across suggest something like this for your models:

this.model.on('change', this.render, this);

In my particular case, I'm creating a view for my model that is a form , and the fields are tied to model properties. When the user updates a field on the form , the model should also be updated. This has not been a problem, as I have events bound to the fields that fire off the appropriate code to update my model.

However , the problem I'm running across is that I also want the view to update when the model does (as in the above mentioned ubiquitous change event binding). This is causing the view to re-render itself any time a field is updated, because the underlying model is changing. So now any time I change a value on the form , my view is being redrawn. This is both inefficient, and causing lots of frustrating bugs (like focus being lost).

How is this problem normally handled?

Answer 1

http://backbonejs.org/#Events-catalog

When you don't want your model change to trigger your view's rendering, use {silent: true} . As of the last version of Backbone, this will completely silence the change (it was previously just shut until the next non-silent change). So when the change to your model comes from some user input, use the silent flag.

Answer 2

如果您想在不触发变更事件事件的情况下更新模型，可以通过调用来进行，

this.model.set('val', newval, {silent:true});