Dynamic filter within ng-repeat in AngularJS

For my AngularJS app I have an ng-repeat in an ng-repeat like so:

对于我的AngularJS应用程序,我在ng-repeat中有一个ng-repeat,如下所示:

Html:

<div ng-app="myApp">
    <div ng-controller="myController">
        <h2>working filter</h2>
        <div ng-repeat="category in categories">
            <h3>{{category}}</h3>
            <div ng-repeat="item in items | filter:{price.red: 0} ">{{item.name}}</div>
    </div>

        <h2>broken filter</h2>
        <div ng-repeat="category in categories">
            <h3>{{category}}</h3>
            <!-- price[category] should be red, blue, yellow, depending on the category in the ng-repeat -->
            <!-- price[category] should be bigger then 0 (or not zero, negative values will not occur) -->
            <div ng-repeat="item in items | filter:{price[category]: 0} ">{{item.name}}</div>
        </div>

    </div>
</div>

Javascript:

var myApp = angular.module('myApp', []);

myApp.controller('myController', function ($scope) {

    $scope.categories = ['red', 'blue', 'yellow'];
    $scope.items = [
        {name: 'one', price:{red: 0, blue: 1, yellow: 3} },
        {name: 'two', price:{red: 2, blue: 0, yellow: 0}},
    ]    

});

Please see my jsFiddle http://jsfiddle.net/hm8qD/

请看我的jsFiddle http://jsfiddle.net/hm8qD/

So I ran into two problems:

所以我遇到了两个问题:

The flter does not accept [] brackets so I cannot make the filter dynamic, based on the category

flter不接受[]括号,因此我无法根据类别使过滤器动态化

The filter needs to return items that have a price[category] greater then zero.

过滤器需要返回价格[类别]大于零的商品。

For the greater then zero I could just make a custom filter. However as far as I know filters don't accept parameters so I have no way of getting the category (red, blue or yellow) to it.

对于大于零,我可以制作自定义过滤器。但据我所知,过滤器不接受参数,所以我无法获得类别(红色,蓝色或黄色)。

Please note this is an simplified version of my actual code and this context might not make the best of sense. I hope I was clear in explaining what I need the filter to do, since I'm new to AngularJS.

请注意,这是我的实际代码的简化版本,这个上下文可能没有最好的意义。我希望我能清楚地解释我需要过滤器做什么,因为我是AngularJS的新手。

2 个解决方案

#1

Apparently it is actually possible to pass arguments to your filter, but you have to make a custom filter instead of using "filter: expression". What I did was create a custom filter which takes the items and category as arguments and returns the array with filtered items.

显然,实际上可以将参数传递给过滤器,但是您必须创建自定义过滤器而不是使用“filter:expression”。我所做的是创建一个自定义过滤器,它将items和category作为参数,并返回带有过滤项的数组。

myApp.filter('myFilter', function () {
    return function (items, category) {
        var newItems = [];
        for (var i = 0; i < items.length; i++) {
            if (items[i].price[category] > 0) {
                newItems.push(items[i]);
            }
        };

        return newItems;
    }
});

See the updated Fiddle here: http://jsfiddle.net/hm8qD/3/

在这里查看更新的小提琴:http://jsfiddle.net/hm8qD/3/

#2

I found a different and quite neat solution for sending parameters to the filter (written in es6):

我找到了一个不同的,非常简洁的解决方案,用于向过滤器发送参数(用es6编写):

$scope.myFilter = (category) => {
  return (item) => {
    if(category === 'fish' && item.type === 'salmon'){
       return true
    }
    return false
  }
}

the markup would be:

标记将是:

<div ng-repeat="item in items | 
filter:myFilter(someCategory)>
     {{item.name}}
</div>

So basically you can just scope the "category" into the filter as myFilter returns a function on the format expected by the filter.

因此,基本上您可以将“类别”范围限定在过滤器中,因为myFilter返回过滤器所期望的格式的函数。

#1

myApp.filter('myFilter', function () {
    return function (items, category) {
        var newItems = [];
        for (var i = 0; i < items.length; i++) {
            if (items[i].price[category] > 0) {
                newItems.push(items[i]);
            }
        };

        return newItems;
    }
});