javascript 同步时排除模型属性 (Backbone.js)
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Exclude model properties when syncing (Backbone.js)
提问by Simon Boudrias
Is there a way to exclude certain property from my model when I sync?
当我同步时，有没有办法从我的模型中排除某些属性？
For example, I keep in my model information about some view state. Let's say I have a picker module and this module just toggle a selectedattributes on my model. Later, when I call .save()on my collection, I'd want to ignore the value of selectedand exclude it from the sync to the server.
例如，我将有关某些视图状态的信息保留在我的模型中。假设我有一个选择器模块，这个模块只是selected在我的模型上切换一个属性。后来，当我调用.save()我的收藏时，我想忽略 的值selected并将其从同步到服务器中排除。
Is there a clean way of doing so?
有没有一种干净的方法呢？
(Let me know if you'd like more details)
（如果您想了解更多详细信息，请告诉我）
回答by Simon Boudrias
This seems like the best solution (based on @nikoshr referenced question)
这似乎是最好的解决方案（基于@nikoshr 引用的问题）
Backbone.Model.extend({
// Overwrite save function
save: function(attrs, options) {
options || (options = {});
attrs || (attrs = _.clone(this.attributes));
// Filter the data to send to the server
delete attrs.selected;
delete attrs.dontSync;
options.data = JSON.stringify(attrs);
// Proxy the call to the original save function
return Backbone.Model.prototype.save.call(this, attrs, options);
}
});
So we overwrite save function on the model instance, but we just filter out the data we don't need, and then we proxy that to the parent prototype function.
所以我们在模型实例上覆盖了保存函数，但我们只是过滤掉了我们不需要的数据，然后我们将它代理给父原型函数。
回答by byoungb
In Underscore 1.3.3 they added pickand in 1.4.0 they added omitwhich can be used very simply to override your model's toJSONfunction to whitelist attributes with _.pickor blacklist attributes with _.omit.
在 Underscore 1.3.3 中，他们添加了pick，在 1.4.0 中，他们添加了omit，可以非常简单地使用它来覆盖模型的toJSON功能，以使用_.pick将属性列入白名单或将属性列入黑名单_.omit。
And since toJSONis used by the sync command for passing the data to the server I think this is a good solution as long as you do not want these fields wherever else you use toJSON.
并且由于toJSON同步命令使用它来将数据传递到服务器，我认为这是一个很好的解决方案，只要您不希望在其他任何地方使用这些字段toJSON。
Backbone.Model.extend({
blacklist: ['selected',],
toJSON: function(options) {
return _.omit(this.attributes, this.blacklist);
},
});
回答by oak
my solution combine all the above. just use white list instead of black one .. this is good rule in general
我的解决方案结合了以上所有内容。只需使用白名单而不是黑名单..这是一般的好规则
define
定义
attrWhiteList:['id','biography','status'],
and then overwrite the save
然后覆盖保存
save: function(attrs, options) {
options || (options = {});
//here is whitelist or all
if (this.attrWhiteList != null )
// Filter the data to send to the server
whitelisted = _.pick(this.attributes, this.attrWhiteList);
else
whitelisted =this.attributes;
/* it seems that if you override save you lose some headers and the ajax call changes*/
// get data
options.data = JSON.stringify(whitelisted);
if ((this.get('id') == 0) || (this.get('id') == null))
options.type = "POST"
else
options.type = "PUT";
options.contentType = "application/json";
// options.headers = {
// 'Accept': 'application/json',
// 'Content-Type': 'application/json'
// },
// Proxy the call to the original save function
return Backbone.Model.prototype.save.call(this, attrs, options);
},
回答by Pascal
In fact there is a much simpler way of achieving this without messing with backbone save or sync function since you would no be expecting this behaviour to be permanent
事实上，有一种更简单的方法可以实现这一点，而不会弄乱主干保存或同步功能，因为您不会期望这种行为是永久性的
if you look at backbone.js line 1145 you will see that
如果您查看backbone.js 第1145 行，您会看到
// Ensure that we have the appropriate request data.
if (options.data == null && model && (method === 'create' || method === 'update' || method === 'patch')) {
params.contentType = 'application/json';
params.data = JSON.stringify(options.attrs || model.toJSON(options));
}
Which means that you may override the data part of the xhr by putting data in your options
这意味着您可以通过将数据放在您的选项中来覆盖 xhr 的数据部分
Since backbone save requires model.save([attributes], [options])
由于主干保存需要 model.save([attributes], [options])
But remember that attributes like id might be essential to proper saving
但请记住，像 id 这样的属性对于正确保存可能是必不可少的
Example
例子
model.save( {}, { data: JSON.stringify(data) } ) ;
So you should be doing something like this
所以你应该做这样的事情
var data = { id : model.id , otherAttributes : 'value' } ;
model.save( {}, { data : JSON.stringify(data) } );
This do the trick quite well for me and could be used with any backbone with xhr such as fetch, save, delete, ...
这对我来说非常有用，并且可以与任何具有 xhr 的主干一起使用，例如获取、保存、删除......
回答by Nacho
I found some problems with the accepted solution, as options.data modifies the way Backbone makes the calls. Better using options.attrs as this:
我发现已接受的解决方案存在一些问题，因为 options.data 修改了 Backbone 进行调用的方式。更好地使用 options.attrs 如下：
Backbone.Model.extend({
save: function (attrs, options) {
options = options || {};
attrs = _.extend({}, _.clone(this.attributes), attrs);
// Filter the data to send to the server
delete attrs.selected;
options.attrs = attrs;
// Proxy the call to the original save function
return Backbone.Model.prototype.save.call(this, attrs, options);
}
});
回答by Ross Allen
Based on several of the answers, this accounts for cases of null objects and a conditional in Backbone that doesn't sent the contentTypeif options.datais already set:
根据几个答案，这说明了空对象的情况和 Backbone 中不发送contentTypeif 的options.data条件已经设置：
EDITABLE_ATTRIBUTES = ["name", "birthdate", "favoriteFood"];
...
save: function(attrs, options) {
// `options` is an optional argument but is always needed here
options || (options = {});
var allAttrs = _.extend({}, this.attributes, attrs);
var allowedAttrs = _.pick(allAttrs, EDITABLE_ATTRIBUTES);
// If `options.data` is set, Backbone does not attempt to infer the content
// type and leaves it null. Set it explicitly as `application/json`.
options.contentType = "application/json";
options.data = JSON.stringify(allowedAttrs);
return Backbone.Model.prototype.save.call(
this, allowedAttrs, options);
},
回答by John Xiao
Set options.attrs will allow you customise api param:
设置 options.attrs 将允许您自定义 api 参数：
var model = new Backbone.Model();
model.save(null, {
wait: true,
success: function() {
},
attrs: _.omit(model.attributes, 'selected')
});
回答by rinat.io
Since saveuses toJSONwe override it:
由于save使用toJSON我们覆盖它：
toJSON: function(options) {
var attr = _.clone(this.attributes);
delete attr.selected;
return attr;
},
But it may not work if you're using toJSON and need selectedin views for example. Otherwise you probably need to override savemethod.
但是，如果您使用 toJSON 并且需要selected在视图中使用，则它可能不起作用。否则，您可能需要覆盖save方法。
回答by Tallmaris
If it is a one-off occasion, you could use mode.unset('selected', { silent:true })(silent is set only to avoid firing the change event), to remove the attribute... This has the not so nice counter-effect of having to re-set it after saving though.
如果它是一次性的，你可以使用mode.unset('selected', { silent:true })（静音设置只是为了避免触发更改事件），删除属性......这具有在保存后必须重新设置的不太好的反作用尽管。
This said, I totally endorse one of the solutions above. Moreover if this is something you need on a more regular basis.
这就是说，我完全赞同上述解决方案之一。此外，如果这是您经常需要的东西。
回答by Pavel Sedek
To set only desired values, use HTTP PATCH insead of HTTP POST. On the backbone side, just add a patch attribute to the save method:
要仅设置所需的值，请使用 HTTP PATCH 代替 HTTP POST。在主干端，只需在 save 方法中添加一个补丁属性：
entity.save(data,{patch:true})
Using save with this attribute, only fields passed as dataare sent to the server.
使用带有此属性的 save，只有按 as 传递的字段data才会发送到服务器。
