backbone.stickit和HTML格式：如何保存（补丁）仅更改的属性？ [英] backbone.stickit and html-form: How to save (patch) only changed attributes?

问题描述

TL;博士

如何使用backbone.stickit与HTML表单从服务器更改现有模型中取出，仅补丁更改的属性（由用户输入更改HTML表单内）到服务器？

How to use backbone.stickit with a html form to change an existing model fetched from the server and only PATCH the changed attributes (changed by user input within the html form) to the server?

/ TL;博士

我使用 backbone.stickit 在Backbone.js的应用模型绑定一个HTML的形式是一个骨干视图的一部分。这工作得很好，到目前为止，但它变得有点有点复杂，如果我要拯救绑定模型。这是因为我想用补丁的方法，只发送更改的属性到服务器。我试图说明什么我迄今所做的：

I'm using backbone.stickit in a backbone.js application to bind a model to a HTML-form which is part of a backbone view. This works fine so far, but it becomes a little bit complicated if I'm going to save the bound model. This is because I want to use the PATCH-method and only send the changed attributes to the server. I try to illustrate what I've done so far:

撷取来自服务器模型

user = new User(); //instatiate a new user-model
user.fetch(); //fetching the model from the server

console.log(user.changedAttributes()); // Returns ALL attributes, because model was empty

最后一行指出我的问题，因为我觉得我可以用 changedAtrributes（）方法后得到这就需要在服务器上补丁的属性。所以，我想这个解决方法，我发现<一个href=\"http://stackoverflow.com/questions/14485366/avoid-fetch-marking-model-attributes-as-changed\">here

The last line indicates my problem, because I thought I can used the changedAtrributes() method later to get the attributes which need a patch on the server. So I tried this workaround which I found here

user.fetch({
    success: function (model, response, options) {
        model.set({});
    }
});

user.changedAtrributes(); //Returns now "false"

做stickit绑定

现在我使我的看法，并调用 stickit（）方法上来看，做绑定：

Now I render my view and call the stickit() method on the view, to do the bindings:

//Bindings specified in the view:
[...]
bindings: {
  "#username" : "username"
  "#age"      : "age"
}

[...]

//within the render method of the view
this.stickit();

该绑定正常工作和我的用户模型被更新，但 changedAttributes（）保持为空所有的时间。

模型保存到服务器

如果用户已经进行的所有必要的修改，该模型应该被保存到服务器。我想使用PATCH方法，只发送更改的属性到服务器上。

If the user has made all required changes, the model should be saved to the server. I want to use the PATCH method and only send the changed attributes to the server.

user.save(null, {patch:true}); //PATCH method is used but ALL attributes are sent to the server

或

user.save(user.changedAttributes(),{patch : true}); 

在第二种方法有不同的结果：

With the second approach there are different outcomes:

1. 如果我没有使用 user.set（{}） woraround，所有的属性得到修补到服务器


2. 如果我用 changedAttributes的 user.set（{}） woraround返回值（）是假，所有属性都投入到服务器


3. 如果我称之为 user.set（时代，123）之前调用保存（） ，那么只有年龄属性被修补到服务器

1. if I didn't use the user.set({}) woraround, all attributes get PATCHED to the server
2. if I use the user.set({}) woraround the return value of changedAttributes() is "false" and all attributes are PUT to the server
3. if I call a user.set("age","123") before calling save(), then only the age attribute is PATCHED to the server

所以，结果3是我期望的行为，但也有2个问题与这样的：首先stickit似乎并没有使用设置（）方法对模型进行更新的属性，如果他们的HTML表单内改变。第二，如果你调用设置（）有一个属性，后来与另一个，只有第二个属性是由返回changedAttributes（）。

So outcome 3 is my desired behaviour, but there are 2 problems with this: First stickit doesn't seem to use the set() method on the model to update the attributes if they are changed within the html-form. And second, if you call set() with one attribute and afterwards with another, only the second attributes is returned by changedAttributes().

也许我只是在监督的骨干或backbone.stickit文档什么的，所以我没有得到预期的行为工作。有关任何想法？

Maybe I just overseen something in the backbone or backbone.stickit docs, so I didn't get the desired behaviour working. Any ideas about that?

推荐答案

注意：由于发现的问题没有直接关系backbone.stickit，更多的骨干本身

NOTE: As found out the problem wasn't directly related to backbone.stickit, more to backbone itself.

解决我自己的这个问题，也许这可以帮助别人谁可能就这个问题绊倒：

Solved this problem on my own, maybe this helps someone who may stumble upon this question:

主干只跟踪的不变的属性，但不是的未保存的属性。因此，与

Backbone only keep track of unchanged attributes, but not of unsaved attributes. So with

model.changedAttributes();

你只会得到的模式，因为其中最后被改变的属性。

you will only get the attributes of the model, which was changed since the last

model.set("some_attribute","some_value")

最后，我偶然发现了 backbone.trackit 这是由创作者保持着Backbone.js的插件的backbone.stickit。有了这个插件，你可以跟踪的未保存的属性，然后（自上次 model.save已改变（）所有属性）中保存使用它们模型的-method。示例（我的用例）：

Finally I stumbled upon backbone.trackit which is a backbone.js plugin maintained by the creator of backbone.stickit. With this plugin you can track unsaved attributes (all attributes which have changed since the last model.save()) and then use them in the save-method of a model. Example (my usecase):

Backbone.View.extend({
  bindings: {
    "#name" : "name",
    "#age"  : "age"
  },

  initialize: function () {
    this.model = new User();
    this.model.fetch({
      success: function (model, response, options) {
        //this tells backbone.stickit to track unsaved attributes
        model.startTracking(); 
      }
    });
  },

  render: function () {
    this.$el.html(tmpl);
    this.stickit();
    return this;
  },

  onSaveUserToServer: function () {
    //first argument: only unsaved attributes, second argument: tell backbone to PATCH
    this.model.save(this.model.unsavedAttributes(), { patch: true });
  });

});

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