嵌套 Backbone (Marionette) 模型/集合中的冒泡事件 [英] Bubbling events in nested Backbone (Marionette) Models / Collections

问题描述

我们有一个大型 Marionette 应用程序，它使用 Backbone.trackit 来监控模型中未保存的更改.

We have a large Marionette App, that uses Backbone.trackit to monitor unsaved changes in our Models.

我们现在有一些嵌套模型，实际上我们有一个模型，其中包含一个模型集合，其中包含一个模型集合.

We now have some nested models, in fact we have a Model, with a Collection of Models, that contain a Collection of Models.

trackit 不支持在子模型更改时将顶级模型标记为脏" - 由于主干不会冒泡这些更改事件.

trackit doesn't support the top level model being marked as 'dirty' when the child models change - due to backbone not bubbling these change events.

我知道我们可以手动监控这些更改事件，但我正在寻找通用的解决方案.

I know we could manually monitor these change events, but Im looking for a generic solution.

有没有人对以下库或任何其他解决方案有任何经验?

Has anyone had any experience of the following libs or any other solutions for this?

1. backbone-deep-model
2. 骨干关联事件
3. 自定义 Backbone.Model.set 覆盖气泡改变事件

当务之急是让 trackit 处理嵌套事件 - 但我找不到任何添加此内容的 trackit 分支.

The immediate requirement is to get trackit working with nested events - but I cant find any branches to trackit that add this.

所以我想知道是否有人解决过这个问题，或者将上述库与 trackit 结合使用?

So I was wondering if anyone has approached this, or used the above libs in conjunction with trackit?

理想情况下，如果一个库会在整个链中触发一个标准的更改"事件，那么 trackit 就会注意到这一点并开始工作.

Ideally, if a library would trigger a standard 'change' event all the way up the chain, then trackit would just pick up on this and start working.

因此，如果 model.countries[3].regions[4].name 改变，change:countries 事件将在 model.因此，如果模型启用了 trackit，它就可以正常工作！

so, if model.countries[3].regions[4].name changed, a change:countries event would be triggered on model. Thus if the model had trackit enbaled, it would all just work!

推荐答案

默认情况下，来自集合内模型的事件已经冒泡到集合中.所以这是一件事解决了，我们只需要从集合或模型中的另一个模型中冒泡事件.

The events from models inside a collection already bubbles to the collection by default. So that's one thing solved and we just need to bubble events from a collection or another model inside a model.

我在层次结构中原样看到的冒泡事件的一个问题是，当您想收听那个特定集合或模型时，您会得到误报.

One problem I see with bubbling events as-is up the hierarchy is that you then get false positive when you want to listen to that specific collection or model.

避免这种情况的一种方法是冒泡的命名空间事件，但这可能不适用于 trackit.

A way to avoid that is to namespace events that are bubbling up, but that may not work with trackit.

一个模型的简单实现，它可以使任意集合或其他嵌套模型的事件冒泡:

A simple implementation of a model that enables bubbling up events of arbitrary collections or other nested models:

var BubblingModel = Backbone.Model.extend({
    /**
     * Bubbles up any event triggered by 'object'.
     * @param {Backbone.Events} obj which implement the Backbone Events.
     * @param {String} key optional namespace name, default to 'nested'.
     */
    addNested: function(obj, key) {
        return this.listenTo(obj, 'all', function() {
            arguments[0] = (key || 'nested') + ':' + arguments[0];
            this.trigger.apply(this, arguments);
        });
    },
    removeNested: function(obj) {
        return this.stopListening(obj);
    }
});

并使用它:

var collection = new Backbone.Collection(),
    model = new BubblingModel();
model.addNested(collection, 'optional-key');

来自 collection 的任何事件都将以其可选的 key 或默认的 nested 字符串作为前缀.collection 触发的 change:myAttribute 事件将是:

Any events from collection will be prefixed by its optional key or by the default nested string. A change:myAttribute event triggered by collection would be:

"optional-key:change:myAttribute"

概念验证，通过简单的测试:

// The simple implementation
var BubblingModel = Backbone.Model.extend({
    /**
     * Bubbles up any event triggered by 'object'.
     * @param {Backbone.Events} obj which implement the Backbone Events.
     * @param {String} key optional namespace name, default to 'nested'.
     */
    addNested: function(obj, key) {
        return this.listenTo(obj, 'all', function() {
            arguments[0] = (key || 'nested') + ':' + arguments[0];
            this.trigger.apply(this, arguments);
        });
    },
    removeNested: function(obj) {
        return this.stopListening(obj);
    }
});

// Setting up a test with multiple nesting
var model5 = new Backbone.Model(),
    model4 = new Backbone.Model(),
    model3 = new BubblingModel({ model: model4 }),
    col2 = new Backbone.Collection([model3]),
    model2 = new BubblingModel({ col: col2 }),
    col1 = new Backbone.Collection([model2]),
    model1 = new BubblingModel({ col: col1 });

// Set which you want to bubble up.
model3.addNested(model4, 'model3-nested-model');
model2.addNested(col2, 'model2-nested-col')
    .addNested(model5);
model1.addNested(col1, 'model1-nested-col');

// listen from any model down the chain
Backbone.listenTo(model2, 'all', function(eventName) {
    console.log("model2:", eventName);
});
Backbone.listenTo(model1, 'all', function(eventName) {
    console.log("model1:", eventName);
});

// trigger default or custom events
model3.set('test', 1);
model3.trigger('model3');
model4.trigger('model4');
model5.trigger('model5');

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