angularjs如何使用多个其他过滤器对整数进行过滤？

Question

我希望这个问题的标题不会让任何人感到困惑 - 但我需要找出一些看起来很基本的东西，但我似乎无法“明白”...

基本上我有多个过滤器，其中两个过滤数字。但是，如果我选择“1”，如果一个数字是“1”（加利福尼亚在jsFiddle的例子中），另一个是“13”（亚利桑那州），则过滤将包括两者。

这里是我的HTML：

<div ng-app='app' ng-controller='myController'> 
<h3>Records: {{(projects|filter:filter).length}} of {{projects.length}}</h3> 
<p><input type="text" name="generalSearch" placeholder="Search Project Title" ng-model="filter.name"></p> 
<p><select ng-model="filter.stateID" 
     ng-options="item.stateID as item.state for item in st_option">  </select> 
    <select ng-model="filter.countyID" 
     ng-options="item.countyID as item.county for item in co_option | filter:{ co_state_id : filter.stateID }"> 
    </select></p> 

    <p><a href="" id="clear-filter" ng-click="clearFilter()">Reset Filters</a></p> 

    <div ng-repeat="project in projects | filter:filter"> 
    <div> 
    <br>Name: {{ project.name }} 
    <br>State: {{project.state}} 
    <br>County: {{project.county}} 
    <br> 
    <span ng-hide="{{project.stateID}} "></span> 
    <span ng-hide="{{project.countyID}} "></span> 
</div> 

JavaScript代码：

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

app.controller('myController', function($scope) { 
    $scope.projects = [{ 
    name: 'First thing', 
    state: 'CA', 
    stateID: '1', 
    county: 'Orange', 
    countyID: '191' 
    }, { 
    name: 'Another Thing', 
    state: 'CA', 
    stateID: '1', 
    county: 'LosAngeles', 
    countyID: '190' 
    }, { 
    name: 'In California', 
    state: 'CA', 
    stateID: '1', 
    county: 'Orange', 
    countyID: '191' 
    }, { 
    name: 'Hey Arizona!', 
    state: 'Arizona', 
    stateID: '13', 
    county: 'Multiple Counties', 
    countyID: '3178' 
    },{ 
    name: 'hello Utah', 
    state: 'Utah', 
    stateID: '14', 
    county: 'Utah County', 
    countyID: '200' 
    }]; 

    $scope.st_option = [{ 
    state: "California", 
    stateID: "1" 
    }, { 
    state: "Arizona", 
    stateID: "13" 
    },{ 
    state: "Utah", 
    stateID: "14" 
    }]; 

    $scope.co_option = [{ 
    county: "Orange", 
    countyID: "191", 
    co_state_id: "1" 
    }, { 
    county: "Multiple Counties", 
    countyID: "3178", 
    co_state_id: "13" 
    }, { 
    county: "Sonoma", 
    countyID: "218", 
    co_state_id: "1" 
    }, { 
    county: "Los Angeles", 
    countyID: "190", 
    co_state_id: "1" 
    }, { 
    county: "Utah County", 
    countyID: "200", 
    co_state_id: "14" 
    }]; 

    $scope.filter = {}; 
$scope.clearFilter = function() { 
    $scope.filter = {}; 
    }; 
}); 

我创建了一个的jsfiddle这里：

https://jsfiddle.net/webmastersean/4m2d5n8u/

我知道我需要添加“真实”的过滤器，但我不知道在哪里或如何。

Answer 1

filter具有第三参数，比较器功能。作为语法糖，这第三个参数也可以取值true来表示严格的比较。这意味着，所有你需要做的就是添加:true到贵县过滤器的结尾：

<select ng-model="filter.countyID" 
     ng-options="item.countyID as item.county for item in co_option | filter:{ co_state_id : filter.stateID }:true"> 
</select> 

Updated fiddle。现在，当你选择加州时，你只能在加利福尼亚州获得县。