在HeadDirective.prototype.link
的以下代码中,this
等于全局window
对象,而不是HeadDirective
实例。我的理解是原型函数中this
的值是包含对象本身。
var HeadDirective = (function () {
function HeadDirective($rootScope, $compile) {
this.$rootScope = $rootScope;
this.$compile = $compile;
this.restrict = 'E';
}
HeadDirective.prototype.link = function (scope, elem) {
var html = '<link rel="stylesheet" ng-repeat="cssUrl in routeStyles" ng-href="{{cssUrl}}" />';
elem.append(this.$compile(html)(scope));
scope.routeStyles = [];
this.$rootScope.$on('$routeChangeStart', function (e, next, current) {
if (next && next.$$route && next.$$route.css) {
if (!Array.isArray(next.$$route.css)) {
next.$$route.css = [next.$$route.css];
}
angular.forEach(next.$$route.css, function (sheet) {
scope.routeStyles.push(sheet);
});
}
});
this.$rootScope.$on('$routeChangeSuccess', function (e, next, current) {
if (current && current.$$route && current.$$route.css) {
if (!Array.isArray(current.$$route.css)) {
current.$$route.css = [current.$$route.css];
}
angular.forEach(current.$$route.css, function (sheet) {
scope.routeStyles.splice(scope.routeStyles.indexOf(sheet), 1);
});
}
});
};
return HeadDirective;
})();
directives.directive('head', [
'$rootScope', '$compile', function ($rootScope, $compile) {
return new HeadDirective($rootScope, $compile);
}]);
以上代码是从以下TypeScript生成的:
class HeadDirective implements ng.IDirective {
constructor(private $rootScope: ng.IRootScopeService, private $compile: ng.ICompileService) {}
link(scope: IScope, elem: JQuery): void {
var html = '<link rel="stylesheet" ng-repeat="cssUrl in routeStyles" ng-href="{{cssUrl}}" />';
elem.append(this.$compile(html)(scope));
scope.routeStyles = [];
this.$rootScope.$on('$routeChangeStart', (e: ng.IAngularEvent, next?: IRoute, current?: IRoute): any => {
if(next && next.$$route && next.$$route.css){
if(!Array.isArray(next.$$route.css)){
next.$$route.css = [next.$$route.css];
}
angular.forEach(next.$$route.css, (sheet: string) => {
scope.routeStyles.push(sheet);
});
}
});
this.$rootScope.$on('$routeChangeSuccess', (e: ng.IAngularEvent, next?: IRoute, current?: IRoute): any => {
if(current && current.$$route && current.$$route.css){
if(!Array.isArray(current.$$route.css)){
current.$$route.css = [current.$$route.css];
}
angular.forEach(current.$$route.css, (sheet) => {
scope.routeStyles.splice(scope.routeStyles.indexOf(sheet), 1);
});
}
});
}
restrict = 'E';
}
directives.directive('head', ['$rootScope','$compile', ($rootScope: ng.IRootScopeService, $compile: ng.ICompileService): ng.IDirective =>{
return new HeadDirective($rootScope, $compile);
}]);
根据最新的TypeScript语言规范:
表达式中
this
的类型取决于引用发生的位置:
- 在构造函数中,实例成员函数,实例成员访问器或实例成员变量初始值设定项
this
属于包含类的类实例类型。- 在静态成员函数或静态成员访问器中,
this
的类型是包含类的构造函数类型。- 在函数声明或标准函数表达式中,
this
的类型为Any。- 在全局模块中,
this
的类型为Any。在所有其他上下文中,引用它是一个编译时错误。
TypeScript语言规范非常清楚。在成员函数(编译成原型函数)中,this
引用类实例。这显然不是我所看到的。
有什么想法吗? Browserify会干扰this
吗?