AngularJS:如何在加载时阻止页面中的“代码闪存”

时间:2015-02-14 09:31:44

标签: javascript angularjs zurb-foundation fouc

我使用AngularJS创建了一个简单的应用程序。当我打开页面一秒钟时,我会看到下面的屏幕:

enter image description here

然而,在加载完成后,我看到加载和样式化的内容很好:

enter image description here

如何防止页面上的AngularJS代码闪存?这与FOUC有关吗?

以下是HTML代码:

<!doctype html>
<html class="no-js" lang="en" ng-app="MainApp">

<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Foundation | Welcome</title>
    <link rel="stylesheet" href="css/foundation.css" />
    <script src="js/vendor/modernizr.js"></script>

    <style>
    .row.full-width {
        width: 100%;
        margin-left: auto;
        margin-right: auto;
        max-width: initial;
    }
    </style>

</head>

<body ng-controller="MainCtrl">
    <div class="off-canvas-wrap" data-offcanvas>
        <div class="inner-wrap">
            <nav class="tab-bar">
                <section class="right-small">
                    <a class="right-off-canvas-toggle menu-icon" href="#"><span></span></a>
                </section>
                <section class="left tab-bar-section">
                    <h1 class="title">Salary Calculator</h1>
                </section>
            </nav>

            <aside class="right-off-canvas-menu">
                <ul class="off-canvas-list">
                    <li>
                        <label>Location</label>
                    </li>
                    <li><a href="#">United Kingdom</a>
                    </li>
                </ul>
            </aside>

            <section class="main-section">


                <div class="row full-width">
                    <div class="large-4 columns">

                        <ul class="tabs" data-tab>
                            <li class="tab-title active"><a href="#panel1">Annual Salary</a>
                            </li>
                            <li class="tab-title"><a href="#panel2">Monthly Expenses</a>
                            </li>
                        </ul>
                        <div class="tabs-content">
                            <div class="content active" id="panel1">
                                <div class="row">
                                    <div class="large-12 columns">
                                        <input ng-change="calculate()" type="text" placeholder="Salary" ng-model="salary"/>
                                    </div>
                                </div>
                            </div>
                            <div class="content" id="panel2">
                                <div class="row">
                                    <div class="large-4 columns">
                                        <input ng-change="calculate()" type="text" placeholder="Rent" ng-model="rent" />
                                    </div>
                                    <div class="large-4 columns">
                                        <input ng-change="calculate()" type="text" placeholder="Wireless, TV, Home Phone" ng-model="telecom"/>
                                    </div>

                                    <div class="large-4 columns">
                                        <input ng-change="calculate()" type="text" placeholder="TV License" ng-model="tv" />
                                    </div>
                                </div>

                                <div class="row">
                                    <div class="large-4 columns">
                                        <input ng-change="calculate()" type="text" placeholder="Mobile Phone" ng-model="mobile"/>
                                    </div>
                                    <div class="large-4 columns">
                                        <input ng-change="calculate()" type="text" placeholder="Subscription" ng-model="subscription"/>
                                    </div>

                                    <div class="large-4 columns">
                                        <input ng-change="calculate()" type="text" placeholder="Electricty" ng-model="electricity" />
                                    </div>
                                </div>

                                <div class="row">
                                    <div class="large-4 columns">
                                        <input ng-change="calculate()" type="text" placeholder="Food" ng-model="food"/>
                                    </div>
                                    <div class="large-4 columns">
                                        <input ng-change="calculate()" type="text" placeholder="Transport" ng-model="transport" />
                                    </div>

                                    <div class="large-4 columns">
                                        <input ng-change="calculate()" type="text" placeholder="Charity" ng-model="charity"/>
                                    </div>
                                </div>

                                <div class="row">
                                    <div class="large-12 columns">
                                        <input ng-change="calculate()" type="text" placeholder="Other" ng-model="other"/>
                                    </div>
                                </div>

                            </div>
                        </div>

                    </div>
                    <div class="large-8 columns"  ng-cloak >
                        <table >
                       <thead>
                            <tr>
                                <th width="200"></th>
                                <th width="250">Yearly</th>
                                <th width="250">Monthly</th>
                                <th width="250">Weekly</th>
                                <th width="250">Daily</th>
                            </tr>
                        </thead>
                        <tbody ng-repeat="val in results">
                            <tr>
                                <td>{{val.rowType}}</td>
                                <td>{{val.yearly}}</td>
                                <td>{{val.monthly}}</td>
                                <td>{{val.weekly}}</td>
                                <td>{{val.daily}}</td>

                            </tr>
                        </tbody>
                        </table>

                    </div>
                </div>



            </section>

            <a class="exit-off-canvas"></a>

        </div>
    </div>

    <script src="../bower_components/angularjs/angular.js"></script>


    <script src="js/app-service.js"></script>
    <script src="js/app-controller.js"></script>
    <script src="js/app-directives.js"></script>
    <script src="js/app.js"></script>

    <script src="js/vendor/jquery.js"></script>
    <script src="js/foundation.min.js"></script>

    <script>
    $(document).foundation();
    </script>
</body>

</html>

编辑:

除了可接受的解决方案之外,请参阅my answer以获得替代解决方案。

4 个答案:

答案 0 :(得分:23)

ng-cloak在某种程度上会有所帮助,但您可以使用ng-bind指令而不是{{ }}来完全阻止它。

e.g。

<td ng-bind="val.monthly"> </td>

不是

<td>{{val.monthly}}</td>

答案 1 :(得分:5)

已经很长时间了,但这是我的工作解决方案:

您需要在html的body标签上使用ng-cloak,但最重要的部分是以下CSS:

[ng\:cloak], [ng-cloak], [data-ng-cloak], [x-ng-cloak], .ng-cloak, .x-ng-cloak { display: none !important; }

对于我来说,我必须添加这个才能让ng-cloak工作。这可能不是解决这个问题的唯一方法,可以在其他答案中看到。希望这有助于某人。

答案 2 :(得分:4)

Angular已经为您提供了阻止此操作的工具:ngCloakhttps://docs.angularjs.org/api/ng/directive/ngCloak

只需将指令放在您的身体上就像<body ng-cloak>一样,它应该有效。

修改 文档还建议您实际上不要将它放在正文上,而是放在页面的较小部分 - 无论您何时看到需要。根据页面的大小,这是一个好主意。对于较小的页面,我把它放在身上,从来没有遇到过问题。

答案 3 :(得分:4)

ng-cloak一起,您可以在路由器中使用resolve object。这将阻止控制器实例化并从视图中呈现,直到数据存在。

在以下示例中,我假设您使用的是uiRouter。相同的模式适用于ngRouter

您的州配置:

$stateProvider
    .state('yourState',{
        templateUrl: 'yourTemplate.html',
        controller: 'YourController as vm',
        resolve: YourController.resolve
    })

如您所见,您已将状态的resolve属性设置为控制器上的静态解析对象。现在,在解析此对象之前,路径将无法解决。

要设置解析对象,我们假设您的服务yourService具有返回promise的方法getData。这是非常重要的。因为我们在希望解决之前不希望路线得到解决

所以你的控制器可能看起来像这样。

YourController.$inject = ['yourService'];
function YourController(yourService) {
    var self = this;
    yourService.getData().then((data) { self.data = data});
}

这是非常标准的。您可以使用vm.data从视图中访问数据,但会看到{{vm.data}}的闪烁。也就是说,如果我们删除了我们已添加到状态配置的解析。

所以现在我们更改控制器以添加静态解析对象以使用我们添加到状态配置中的resolve

YourController.resolve = {
    'yourService': 'yourService',
    'data': ['yourService', function(yourService) {
        return yourService.getData();    
    }]
}

YourController.$inject = ['data'];
function YourController(data) {
    this.data = data;
}

所以现在我们有了一个解决方案对象。 yourService将作为普通服务解析,但data属性仅在getData()返回的承诺得到解决时解析。然后使用Dependancy Injection将此data直接传递给控制器​​。

实际上,如果您使用ng-cloak,则可能不需要使用resolve

这是一个有效的例子:

angular.module('app', ['ui.router'])

.config(['$stateProvider',
  function($stateProvider) {

    $stateProvider
    
      .state('noDot', {
        controller: "NoDotController",
        template: "Using a old style $scope binding {{customers[0].CutomerName}}"
      })
             
      .state('noResolve', {
        controller: "NoResolveController as vm",
        template: "We are displaying things before the data is here {{vm.customers[0].CustomerName}}"
      })

    .state('withResolve', {
      controller: "WithResolveController as vm",
      template: "We are waiting for data before displaying anything {{vm.customers[0].CustomerName}}",
      resolve: WithResolveController.resolve
    })

    .state('empty', {
      template: ""
    })

  }
])

.controller('NoResolveController', NoResolveController)
  .controller('NoDotController', NoDotController)
  .controller('WithResolveController', WithResolveController)
  .service('northwind', Northwind);

NoDotController.$inject = ['$scope', 'northwind'];
function NoDotController($scope, northwind) {
  northwind.getCustomers().then(function(customers) {
    $scope.customers = customers});
}

NoResolveController.$inject = ['northwind'];
function NoResolveController(northwind) {
  var self = this;
  northwind.getCustomers().then(function(customers) {
    self.customers = customers;
  });
}

WithResolveController.resolve = {
  'northwind': 'northwind',
  'customers': ['northwind',
    function(northwind) {
      return northwind.getCustomers();
    }
  ]
}
WithResolveController.$inject = ['customers'];
function WithResolveController(customers) {
  this.customers = customers;
}

Northwind.$inject = ['$timeout', '$q'];
function Northwind($timeout, $q) {
  this.$q = $q;
  this.$timeout = $timeout;
}
Northwind.prototype.getCustomers = function() {
  var deferred = this.$q.defer();

  this.$timeout(function() {
    deferred.resolve([{CustomerName: "Name of Customer"}])
  }, 1000);

  return deferred.promise;
}
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular-ui-router/0.2.13/angular-ui-router.js"></script>
<div ng-app="app">
  <a ui-sref="noDot" href="#">No Dot</a>
  <span> | </span>
  <a ui-sref="empty" href="#">Emtpy</a>
  <span> | </span>
  <a ui-sref="noResolve" href="#">No Resolve</a>
  <span> | </span>
  <a ui-sref="empty" href="#">Emtpy</a>
  <span> | </span>
  <a ui-sref="withResolve" href="#">With Resolve</a>
  <br>
  <br>
  <ui-view></ui-view>

</div>