AngularJS在为当前页面的链接设置一个活动类方面有任何帮助吗?

我想一定有什么神奇的方法可以做到,但我似乎找不到。

我的菜单是这样的:

 <ul>
   <li><a class="active" href="/tasks">Tasks</a>
   <li><a href="/actions">Tasks</a>
 </ul>

我在我的路由中为它们每个都有控制器:TasksController和ActionsController。

但是我想不出一种方法将a链接上的“活动”类绑定到控制器。

有提示吗?


当前回答

也有同样的问题。以下是我的解决方案:

.directive('whenActive',
  [
    '$location',
    ($location)->
      scope: true,
      link: (scope, element, attr)->
        scope.$on '$routeChangeSuccess', 
          () ->
            loc = "#"+$location.path()
            href = element.attr('href')
            state = href.indexOf(loc)
            substate = -1

            if href.length > 3
              substate = loc.indexOf(href)
            if loc.length is 2
              state = -1

            #console.log "Is Loc: "+loc+" in Href: "+href+" = "+state+" and Substate = "+substate

            if state isnt -1 or substate isnt -1
              element.addClass 'selected'
              element.parent().addClass 'current-menu-item'
            else if href is '#' and loc is '#/'
              element.addClass 'selected'
              element.parent().addClass 'current-menu-item'
            else
              element.removeClass 'selected'
              element.parent().removeClass 'current-menu-item'
  ])

其他回答

在我的例子中,我通过创建一个负责导航的简单控制器来解决这个问题

angular.module('DemoApp')
  .controller('NavigationCtrl', ['$scope', '$location', function ($scope, $location) {
    $scope.isCurrentPath = function (path) {
      return $location.path() == path;
    };
  }]);

只需像这样在元素中添加ng-class:

<ul class="nav" ng-controller="NavigationCtrl">
  <li ng-class="{ active: isCurrentPath('/') }"><a href="#/">Home</a></li>
  <li ng-class="{ active: isCurrentPath('/about') }"><a href="#/about">About</a></li>
  <li ng-class="{ active: isCurrentPath('/contact') }"><a href="#/contact">Contact</a></li>
</ul>

如果你想把指令的链接放在一个包装器中,而不是选择每个单独的链接(这样更容易查看Batarang中的作用域),这也很有效:

  angular.module("app").directive("navigation", [
    "$location", function($location) {
      return {
        restrict: 'A',
        scope: {},
        link: function(scope, element) {
          var classSelected, navLinks;

          scope.location = $location;

          classSelected = 'selected';

          navLinks = element.find('a');

          scope.$watch('location.path()', function(newPath) {
            var el;
            el = navLinks.filter('[href="' + newPath + '"]');

            navLinks.not(el).closest('li').removeClass(classSelected);
            return el.closest('li').addClass(classSelected);
          });
        }
      };
    }
  ]);

加价就是:

    <nav role="navigation" data-navigation>
        <ul>
            <li><a href="/messages">Messages</a></li>
            <li><a href="/help">Help</a></li>
            <li><a href="/details">Details</a></li>
        </ul>
    </nav>

我还应该提到,我在这个例子中使用的是“全脂”jQuery,但你可以很容易地改变我所做的过滤等。

我刚刚写了一个指令。

用法:

<ul class="nav navbar-nav">
  <li active><a href="#/link1">Link 1</a></li>
  <li active><a href="#/link2">Link 2</a></li>
</ul>

实现:

angular.module('appName')
  .directive('active', function ($location, $timeout) {
    return {
      restrict: 'A',
      link: function (scope, element, attrs) {
        // Whenever the user navigates to a different page...
        scope.$on('$routeChangeSuccess', function () {
          // Defer for other directives to load first; this is important
          // so that in case other directives are used that this directive
          // depends on, such as ng-href, the href is evaluated before
          // it's checked here.
          $timeout(function () {
            // Find link inside li element
            var $link = element.children('a').first();

            // Get current location
            var currentPath = $location.path();

            // Get location the link is pointing to
            var linkPath = $link.attr('href').split('#').pop();

            // If they are the same, it means the user is currently
            // on the same page the link would point to, so it should
            // be marked as such
            if (currentPath === linkPath) {
              $(element).addClass('active');
            } else {
              // If they're not the same, a li element that is currently
              // marked as active needs to be "un-marked"
              element.removeClass('active');
            }
          });
        });
      }
    };
  });

测试:

'use strict';

describe('Directive: active', function () {

  // load the directive's module
  beforeEach(module('appName'));

  var element,
      scope,
      location,
      compile,
      rootScope,
      timeout;

  beforeEach(inject(function ($rootScope, $location, $compile, $timeout) {
    scope = $rootScope.$new();
    location = $location;
    compile = $compile;
    rootScope = $rootScope;
    timeout = $timeout;
  }));

  describe('with an active link', function () {
    beforeEach(function () {
      // Trigger location change
      location.path('/foo');
    });

    describe('href', function () {
      beforeEach(function () {
        // Create and compile element with directive; note that the link
        // is the same as the current location after the location change.
        element = angular.element('<li active><a href="#/foo">Foo</a></li>');
        element = compile(element)(scope);

        // Broadcast location change; the directive waits for this signal
        rootScope.$broadcast('$routeChangeSuccess');

        // Flush timeout so we don't have to write asynchronous tests.
        // The directive defers any action using a timeout so that other
        // directives it might depend on, such as ng-href, are evaluated
        // beforehand.
        timeout.flush();
      });

      it('adds the class "active" to the li', function () {
        expect(element.hasClass('active')).toBeTruthy();
      });
    });

    describe('ng-href', function () {
      beforeEach(function () {
        // Create and compile element with directive; note that the link
        // is the same as the current location after the location change;
        // however this time with an ng-href instead of an href.
        element = angular.element('<li active><a ng-href="#/foo">Foo</a></li>');
        element = compile(element)(scope);

        // Broadcast location change; the directive waits for this signal
        rootScope.$broadcast('$routeChangeSuccess');

        // Flush timeout so we don't have to write asynchronous tests.
        // The directive defers any action using a timeout so that other
        // directives it might depend on, such as ng-href, are evaluated
        // beforehand.
        timeout.flush();
      });

      it('also works with ng-href', function () {
        expect(element.hasClass('active')).toBeTruthy();
      });
    });
  });

  describe('with an inactive link', function () {
    beforeEach(function () {
      // Trigger location change
      location.path('/bar');

      // Create and compile element with directive; note that the link
      // is the NOT same as the current location after the location change.
      element = angular.element('<li active><a href="#/foo">Foo</a></li>');
      element = compile(element)(scope);

      // Broadcast location change; the directive waits for this signal
      rootScope.$broadcast('$routeChangeSuccess');

      // Flush timeout so we don't have to write asynchronous tests.
      // The directive defers any action using a timeout so that other
      // directives it might depend on, such as ng-href, are evaluated
      // beforehand.
      timeout.flush();
    });

    it('does not add the class "active" to the li', function () {
      expect(element.hasClass('active')).not.toBeTruthy();
    });
  });

  describe('with a formerly active link', function () {
    beforeEach(function () {
      // Trigger location change
      location.path('/bar');

      // Create and compile element with directive; note that the link
      // is the same as the current location after the location change.
      // Also not that the li element already has the class "active".
      // This is to make sure that a link that is active right now will
      // not be active anymore when the user navigates somewhere else.
      element = angular.element('<li class="active" active><a href="#/foo">Foo</a></li>');
      element = compile(element)(scope);

      // Broadcast location change; the directive waits for this signal
      rootScope.$broadcast('$routeChangeSuccess');

      // Flush timeout so we don't have to write asynchronous tests.
      // The directive defers any action using a timeout so that other
      // directives it might depend on, such as ng-href, are evaluated
      // beforehand.
      timeout.flush();
    });

    it('removes the "active" class from the li', function () {
      expect(element.hasClass('active')).not.toBeTruthy();
    });
  });
});

对于那些使用ui-router的人,我的答案有点类似于Ender2050,但我更喜欢通过州名测试来做到这一点:

$scope.isActive = function (stateName) {
  var active = (stateName === $state.current.name);
  return active;
};

相应的HTML:

<ul class="nav nav-sidebar">
    <li ng-class="{ active: isActive('app.home') }"><a ui-sref="app.home">Dashboard</a></li>
    <li ng-class="{ active: isActive('app.tiles') }"><a ui-sref="app.tiles">Tiles</a></li>
</ul>

我是这样做的:

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

myApp.directive('trackActive', function($location) {
    function link(scope, element, attrs){
        scope.$watch(function() {
            return $location.path();
        }, function(){
            var links = element.find('a');
            links.removeClass('active');
            angular.forEach(links, function(value){
                var a = angular.element(value);
                if (a.attr('href') == '#' + $location.path() ){
                    a.addClass('active');
                }
            });
        });
    }
    return {link: link};
});

这可以让你在一个有跟踪活动指令的节中有链接:

<nav track-active>
     <a href="#/">Page 1</a>
     <a href="#/page2">Page 2</a>
     <a href="#/page3">Page 3</a>
</nav>

在我看来,这种方法比其他方法干净得多。

此外,如果你使用的是jQuery,你可以让它更整洁,因为jQlite只有基本的选择器支持。在angular include之前包含jquery的一个更简洁的版本是这样的:

myApp.directive('trackActive', function($location) {
    function link(scope, element, attrs){
        scope.$watch(function() {
            return $location.path();
        }, function(){
            element.find('a').removeClass('active').find('[href="#'+$location.path()+'"]').addClass('active');
        });
    }
    return {link: link};
});

这是一个jsFiddle