我需要按多个属性对Ember Models的集合进行排序,而不需要在相同的方向/顺序上。即我需要按升序顺序中的属性 a 和降序中的属性 b 进行排序。有没有办法实现这个目标?
我尝试将sortAscending
属性设置为数组,但它无效。
在查看源代码之后,似乎不支持开箱即用(<)。
答案 0 :(得分:15)
在您的ArrayController中:
sortProperties: ["propA:asc", "propB:desc"]
sortedModel: Ember.computed.sort("model", "sortProperties");
然后在模板的sortedModel
处理程序中引用#each
。
答案 1 :(得分:5)
我决定创建一个 mixin ,它允许按多个顺序(方向)进行排序。它将SortableMixin
扩展到尽可能向后兼容的范围。实际上它可以用作常规SortableMixin
。它添加的是sortAscendingProperties
属性,它是排序属性名称(sortProperty
数组的成员)的数组,应按升序排序。如果属性位于sortAscendingProperties
,则将按升序排序,否则将根据sortAscending
进行排序,这是默认值。
我把混合调用MultiSortableMixin
虽然我认为它不是最好的名字。
(function() {
var get = Ember.get, set = Ember.set, forEach = Ember.EnumerableUtils.forEach;
/**
* extends the SortableMixin by allowing sorting by multiple orders.
*
* sortProperties - array of strings
* sortAscending - default sort order
* sortAscendingProperties - properties which are listed here will be sorted in ascending order, those which are not listed - will be sorted according to sortAscending
*/
Ember.MultiSortableMixin = Ember.Mixin.create(Ember.SortableMixin, {
/**
Specifies the arrangedContent's sort direction
@property {Array} sortAscendingProperties
*/
sortAscendingProperties: null,
orderBy: function(item1, item2) {
var result = 0,
sortProperties = get(this, 'sortProperties'),
sortAscending = get(this, 'sortAscending'),
sortAscendingProperties = get(this, 'sortAscendingProperties');
Ember.assert("you need to define `sortProperties`", !!sortProperties);
forEach(sortProperties, function(propertyName) {
if (result === 0) {
result = Ember.compare(get(item1, propertyName), get(item2, propertyName));
//use default sortAscending if propertyName is not listed in sortAscendingProperties
var sa = (sortAscendingProperties && sortAscendingProperties.indexOf(propertyName) > -1) || sortAscending;
if ((result !== 0) && !sa) {
result = (-1) * result;
}
}
});
return result;
},
//overrided to add more watched props. TODO - the contents of this method is the same as parent's - find the way to just add watched stuff
arrangedContent: Ember.computed('content', 'sortProperties.@each', 'sortAscendingProperties.@each', 'sortAscending', function(key, value) {
var content = get(this, 'content'),
isSorted = get(this, 'isSorted'),
sortProperties = get(this, 'sortProperties'),
self = this;
if (content && isSorted) {
content = content.slice();
content.sort(function(item1, item2) {
return self.orderBy(item1, item2);
});
forEach(content, function(item) {
forEach(sortProperties, function(sortProperty) {
Ember.addObserver(item, sortProperty, this, 'contentItemSortPropertyDidChange');
}, this);
}, this);
return Ember.A(content);
}
return content;
}),
// unneeded in this mixin, overrided to disable functionality from SortableMixin. TODO - find a way to just remove it
sortAscendingDidChange: Ember.observer(function() {
//empty
}, 'sortAscending')
});
})();
用法示例:
App.ThingsController = Ember.ArrayController.extend(Ember.MultiSortableMixin, {
sortProperties: ['prop1', 'prop2', 'prop3'],
sortAscending: false,
sortAscendingProperties: ['prop2', 'prop3'],
//your stuff
});
在此示例中,ThingsController
的内容将按 prop1 排序 - 按降序排列,然后按 prop2 和 prop3 排序 - 按升序排列。
答案 2 :(得分:0)
这不是Ember的开箱即用功能。但是查看code of SortableMixin可以看到它使用Ember.compare来比较两个实体:
orderBy: function(item1, item2) {
var result = 0,
sortProperties = get(this, 'sortProperties'),
sortAscending = get(this, 'sortAscending');
Ember.assert("you need to define `sortProperties`", !!sortProperties);
forEach(sortProperties, function(propertyName) {
if (result === 0) {
result = Ember.compare(get(item1, propertyName), get(item2, propertyName));
if ((result !== 0) && !sortAscending) {
result = (-1) * result;
}
}
});
return result;
},
Ember.compare包含对Comparable Mixin:
的检查var Comparable = Ember.Comparable;
if (Comparable) {
if (type1==='instance' && Comparable.detect(v.constructor)) {
return v.constructor.compare(v, w);
}
if (type2 === 'instance' && Comparable.detect(w.constructor)) {
return 1-w.constructor.compare(w, v);
}
}
因此我建议的解决方案是:
1 - 在模型中添加一个附加字段,其中包含所有sortingProperties的包装器对象,例如“combinedAandB”
App.YourModel = Ember.Object.extend({
a : null,
b : null,
combinedAandB : function(){
// the following Object should implement SortableMixin
var comparator = App.AandBComparator.create(this.get("a"), this.get("b"));
return comparator;
}.property("a","b")
2 - 您的ComparatorModel(App.AandBComparator)应该实现Comparable Mixin。在这个比较方法中,尊重你想要的排序行为(支持升序和道具降序)。
3 - 现在您可以实例化一个ArrayController并根据您的组合属性对其进行排序:
var yourModelController = //whereever you may get that one from
yourModelController.set("sortProperties", "combinedAandB");
注意:这只是我在阅读您的要求时得到的一个自发的想法。我还没有实现这一点。所以这可能并不完美: - )