如何在 <head> 中创建 Angular 指令文档的一部分? [英] How to create an Angular directive in the <head> section of a document?
问题描述
我是 angular.js 的新手.我正在尝试创建一个指令以在 html 文档的 <head> 部分添加一些标题和元标记，但我遇到了一些麻烦.
I am new to angular.js. I am trying to create a directive to add some title and meta tags in the <head> section of html documents, but I am having some trouble.
我的index.html文件如下:
<!DOCTYPE html>
<html ng-app="myApp">
<head>
<meta charset="UTF-8">
<base href="/">
<seo-title></seo-title>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.1/angular.min.js"></script>
<script src="https://code.angularjs.org/1.4.1/angular-route.min.js"></script>
<script src="/incl/js/myApp.js"></script>
</head>
<body >
<div ng-view></div>
</body>
</html>
我的 javascript 是:
My javascript is:
var app = angular.module ('myApp', ['ngRoute']);
app.config(['$routeProvider', '$locationProvider', function($routeProvider, $locationProvider) {
$routeProvider
.when('/', { templateUrl: 'routes/home.html'})
.when('/pageA', { templateUrl: 'routes/pageA.html'})
.when('/pageB', { templateUrl: 'routes/pageB.html'})
.otherwise({ redirectTo: '/' });
$locationProvider.html5Mode({
enabled: true
});
}]);
app.directive('seoTitle', function() {
return {
restrict: 'E',
template: '<title>{{seo.title}}</title>'
};
});
当我打开检查器时，指令已经移到了<body>并且没有被模板替换:
When I open the inspector, the directive has been moved to the <body> and has not been replaced with the template:
如何在标题中创建指令?
How can I create directives in the header?
P.S.:代码示例会很棒！
推荐答案
你的指令不需要进入 head 来设置标题.只需让您的指令注入 $window 并设置 $window.document.title = 'your title'.
Your directive does not need to go in the head to set the title. Just have your directive inject $window and set $window.document.title = 'your title'.
更新这是您可以更新元标记的方法.
UPDATE This is how you can update meta tags.
为了更新元标记，我会使用这样的指令:
For updating meta tags I would use a Directive like this:
mmMetaTags.$inject = ['metaTags'];
function mmMetaTags(metaTags) {
return {
restrict: 'A',
link: function(scope, element) {
metaTags.metaTags.forEach(function(tag) {
addMetaTag(tag.name, tag.content)
});
metaTags.subscribe(addMetaTag);
function addMetaTag(name, content) {
var tag = element[0].querySelector('meta[name="' + name + '"]');
if (tag) {
tag.setAttribute('content', content);
} else {
element.append('<meta name="' + name + '" content="' + content + '">');
}
}
}
}
}
directive('mmMetaTags', mmMetaTags);
连同设置元标签的服务:
Along with a service to set the metaTags:
function MetaTags() {
// private
this._tags = [];
// private
this._subscriber;
var self = this;
Object.defineProperty(this, 'metaTags', { get: function() {
return self._tags;
}});
}
MetaTags.prototype.addMetaTag = function(name, content) {
this._tags.push({ name: name, content: content });
this._updateSubscriber(name, content);
}
MetaTags.prototype.subscribe = function(callback) {
if (!this.subscriber) {
this._subscriber = callback;
} else {
throw new Error('Subscriber already attached. Only one subscriber may be added as there can only be one instance of <head>');
}
}
// private
MetaTags.prototype._updateSubscriber = function(name, content) {
this.subscriber(name, content);
}
service('metaTags', MetaTags);
因此，在您的 head 标签中，您将包含属性 mm-meta-tags.然后在您的控制器中，您将注入 metaTags 服务并调用 addMetaTag 来更新标签.
So in your head tag you would include the attribute mm-meta-tags. Then in your controller you would inject the metaTags service and call addMetaTag to update the tags.
这篇关于如何在 <head> 中创建 Angular 指令文档的一部分?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
