如何在AngularJS中使用单选按钮创建自定义过滤器

Question

I have multiple radio buttons, and I want to filter results coming from web API depending on the selected radio button.

HTML

<div class="row">
    <div class="small-8 medium-9 large-10 columns">
        <ul class="no-bullet">
            <li data-ng-repeat="course in courses">
                <a href="#/CoursesWillStart/{{ course.ID }}">{{ course.CourseName }}</a>
            </li>
        </ul>
    </div>

    <div class="small-4 medium-3 large-2 columns">
        <ul class="no-bullet">
            <li>
                <label><input type="radio" name="filterRadio" value="RadioAll" data-ng-model="filterRadio"  /> All</label>
            </li>
            <li>
                <label><input type="radio" name="filterRadio" value="RadioToday" data-ng-model="filterRadio" /> Today</label>
            </li>
            <li>
                <label><input type="radio" name="filterRadio" value="RadioThisWeek" data-ng-model="filterRadio" /> This Week</label>
            </li>
            <li>
                <label><input type="radio" name="filterRadio" value="RadioThisMonth" data-ng-model="filterRadio" /> This Month</label>
            </li>
            <li>
                <label><input type="radio" name="filterRadio" value="RadioSpecificDate" data-ng-model="filterRadio" /> Specific Date
                    <input type="date" name="from" data-ng-model="from" data-ng-show="filterRadio == 'RadioSpecificDate'" />
                    <input type="date" name="to" data-ng-model="to" data-ng-show="filterRadio == 'RadioSpecificDate'" />
                </label>
            </li>
            <li>
                 <button class="my-button" data-ng-click="filterCourses(filterRadio)">Search</button>
            </li>
        </ul>
    </div>
</div>

Javascript (relevant)

myApp.controller('CoursesWillStartCtrl', ['$scope', 'GetCoursesWillStart',
function ($scope, GetCoursesWillStart) {

    $scope.filterRadio = 'RadioAll';

    $scope.filterCourses = function (filterRadio) {
        switch (filterRadio) {
            case 'RadioToday':

                $scope.courses = coursesStartToday();
                break;

            case 'RadioThisWeek':

                $scope.courses = coursesThisWeek();
                break;

            case 'RadioThisMonth':

                $scope.courses = coursesThisMonth();
                break;

            case 'RadioSpecificDate':

                $scope.courses = coursesInSpecificDate($scope.from, $scope.to);
                break;

            default:    //all
                $scope.courses = GetCoursesWillStart.query();
                break;
        }

    };

    $scope.filterCourses($scope.filterRadio);
}
]);

This is my first web application in Angular, and the above code is working, but I don't want to manipulate $scope.courses , so that the user don't have to get all courses after each filtering, and don't overuse the web API.

I think I should make a custom filter. I saw this tutorial , but I don't know how to make it for my requirements. So can someone show me how to make a custom filter -or if there is a better way- to do the filtering?

Answer 1

I found this extremely useful link describing everything about filters. My problem was that I couldn't read values from view to filter .

But Angular takes care of this, just like this

course in courses | filterByDate:filterRadio

Now I sent filterRadio to filter function as argument

angular.module('myAppFilters', []).filter('filterByDate',
function () {
    return function (courses, filterRadio) {
         //Also, I removed the switch from controller and added it here    
    }
});

Also, we can send multiple parameters from view like this:

course in courses | filterByDate:filterRadio:from:to

Also an important feature in Angular is alias naming:

course in courses | filterByDate:filterRadio:from:to as coursesFiltered

Now we can get it's length like this coursesFiltered.length