Yaya HttpClient ke aiki?

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**`HttpClient`** aiki na aka gina jiya na Angular don yi ayowar HTTP. Yana dawo **Observables** (ba Promises ba), tana haɗa da RxJS operators, kuma tana goyan bayan amsa masu jeri, interceptors, da daidaitawa na kukaɗi. ## Aiki na yau-yau ```ts import { HttpClient } from "@angular/common/http"; import { Injectable } from "@angular/core"; @Injectable({ providedIn: "root" }) export class UserService { constructor(private http: HttpClient) {} getUsers() { return this.http.get("/api/users"); // typed: Observable } createUser(user: User) { return this.http.post("/api/users", user); // body as 2nd arg } deleteUser(id: number) { return this.http.delete(`/api/users/${id}`); } } ``` Jerenin (``) ya daidaita da amsa. Bukatu sune **lazy** — suna aiki kawai idan aka yi harƙa. ## Amfani a cikin skarni ```ts ngOnInit() { this.userService.getUsers().subscribe(users => this.users = users); } // or with the async pipe (no manual subscribe/unsubscribe): users$ = this.userService.getUsers(); // template:

``` ## Zaɓuwar bukatu: params, headers ```ts import { HttpParams, HttpHeaders } from "@angular/common/http"; this.http.get("/api/users", { params: new HttpParams().set("page", "1").set("limit", "10"), // ?page=1&limit=10 headers: new HttpHeaders({ Authorization: `Bearer ${token}` }), }); ``` ## Daidaitawa na kukaɗi tare da RxJS ```ts import { catchError, retry } from "rxjs/operators"; import { of } from "rxjs"; this.http.get("/api/users").pipe( retry(2), // retry failed requests twice catchError(err => { console.error(err); return of([]); // fallback value, keep the stream alive }) ).subscribe(users => this.users = users); ``` Domin ya dogara da Observable, kuna haɗa sake koyo, fallbacks, timeouts, da canji da operators. ## Interceptors suna jura bukatun cross-cutting ```text HTTP interceptors automatically attach auth tokens, log requests, handle errors globally, or show loading spinners — for ALL requests. ``` ## Yaya ya sa yana muhimmi `HttpClient` hanya da Angular apps ke magana da backend — masu jeri, Observable-masu tushe, da masu haɓa tare da RxJS don sake koyo/fallbacks/canji. Hali Observable nsa (ga waɗannan fetch's Promises) ya haɗa ta tare da sauran Angular (async pipe, operators, interceptors). Sanin bukatu masu jeri, zaɓuwa, daidaitawa na kukaɗi, da haɗa tare da `async` pipe ya rufe kusan duk niyoyin samun bayanai a cikin Angular.