如何实现表单的自动保存？(How to implement auto save for a form?)

我计划在FormBuilder的帮助下使用ReactiveForms。 我想知道自动保存可以实施的方式。 我需要以下行为：

页面上没有提交按钮。 当用户在表单中进行更改时，数据会自动保存并发送到服务器。

如何在Angular2中实现这一目标？

谢谢。

I plan on using ReactiveForms with the help of FormBuilder. And I'm wondering in which way auto save can be implemented. I need the following behaviour:

There's no submit button on a page. When user makes changes within a form, the data is automatically saved and gets sent to a server.

How can this be achieved in Angular2?

Thank you.

最满意答案

您可以订阅表单的valueChanges事件。 然后只需检查表单是否有效，然后在每次更改时保存数据。

this.form = new FormGroup({...});
this.form.valueChanges.subscribe(val => { this.saveMyFormValue(val); });
 
 valueChanges是抽象类AbstractControl一个属性。 FormGroup ， FormControl和FormArray都实现了AbstractControl ，这意味着如果您愿意，也可以为单个表单控件订阅此事件。 
You can subscribe to the valueChanges event of your form. Then simply check if the form is valid and then save your data on every change.
 
this.form = new FormGroup({...});
this.form.valueChanges.subscribe(val => { this.saveMyFormValue(val); });
 
valueChanges is a property on the abstract class AbstractControl. FormGroup, FormControl and FormArray all implement AbstractControl, meaning that you can also subscribe to this event for individual form controls if you'd wish to.