服務:角2路由映射經由JSON
export class ArticlesService {
private _url = 'https://example.firebaseio.com/.json';
constructor(private _http: Http) {
}
getAllArticles(): Observable<any> {
return this._http.get(this._url)
.map((response: Response) => response.json())
.catch((error) => Observable.throw(error));
}
getAnArticle(articleId: any): Observable<any> {
return this._http.get(this._url.replace(".json", articleId + ".json"))
.map((response: Response) => response.json())
.catch((error) => Observable.throw(error));
}
}
組件:
theArticle = {};
constructor(private _activatedRoute: ActivatedRoute, private _articlesService: ArticlesService, private _router: Router) {
this._router.events
.filter(theEvent => theEvent instanceof NavigationStart)
.subscribe((theEvent: NavigationStart) => {
if (/\/articles\/\d/.test(theEvent.url)) {
const urlDetails = theEvent.url.split('/');
const articleId = urlDetails[urlDetails.length - 1];
this.getArticleDetails(articleId);
console.log(this.theArticle);
}
});
}
ngOnInit() {
this.getArticleDetails(this._activatedRoute.snapshot.params['id']);
}
getArticleDetails(articleId: any) {
if (articleId != null) {
this._articlesService.getAnArticle(articleId - 1)
.subscribe(data => {
this.theArticle = data;
});
}
}
路由器:
{ path: 'articles/:id', component: PArticlesComponent }
HTML:
(導航)
<ul class="sidebar-ul" *ngIf="allArticles.length">
<li *ngFor="let anArticle of limit(allArticles)">
<a [routerLink]="['/articles', anArticle.id]">{{anArticle.title}}
<br/>
<span class="date">{{formatDate(anArticle.createdOn)}}</span>
</a>
</li>
</ul>
(物品)
<div *ngIf="theArticle.id">
<h2 class="article-title">
<a href="#">{{theArticle.title}}</a>
</h2>
<div class="meta">
<p class="date">{{formatDate(theArticle.createdOn)}}</p>
</div>
<p [innerHTML]="theArticle.details"></p>
</div>
說明:
的ArticlesService內的getAnArticle函數使用:所選擇的物品的ID參數並將該參數發送到getArticleDetails功能的組件的內部。 getArticleDetails函數然後使用該參數來訂閱該JSON對象的內容。這個對象是這樣的:
{"id":"5","createdOn":1494721160,"title":"title 5","details":"details 5","shorthand":"shorthand-5"}
注意,這是在JSON文件中的第五對象,所以它的密鑰ID號爲4,這就是爲什麼我被1中getArticleDetails功能減去值。
這一切都很好,當點擊一篇文章時,路由器會正確更新以顯示一個URL,例如http://www.example.com/articles/5,但我很難修改代碼,以便URL顯示http://www.example.com/articles/shorthand-5。
我可以讓路由器擁有正確的URL,但由於現在我很容易使用靜態數字並將該值減1以獲得正確的JSON對象,我無法弄清楚如何讀取正確的數據(或關於該事項的任何數據),通過使用:簡寫參數作爲標識符。