如何检查angular2中的templateUrl是否有效？

Question

I build my views using the C# Helpers and angular2 consume this view by call a controller and receiving the html of view generated by C#. But my problem is when the user have no permissions to access the view and the controller returns 401 Unautorized, this produce a error when angular try to template load and the component stay broken until you clean cache and reload with valid authorization.

Any idea that the how can i validate templateUrl before component load ?

Answer 1

I resolved my problem creating a function that is call on templateUrl and return the correct string url.

 function hasTemplate(template: string) { var http = new XMLHttpRequest(); http.open('GET', template, false); http.send(); return (http.status === 200) ? template : '/view/home/error/'; } export const getViewUrl = <TModel>(modelo: { new (): TModel }, tipo: string) => { //Url to call web service and verify the response let url = `/view/${modelo.name.toLowerCase()}/${tipo}`; return hasTemplate(url); }; @Component({ selector: 'cidade-list', templateUrl: getViewUrl(Cidade, 'list'), styleUrls: [CssPath], providers: [ CidadeService, ] }) export class CidadeListComponent {}