Usually, when you want to cache all requests, you do not cache all requests, but only the GET
method. But, for some frontend applications, it is required to cache everything, otherwise the subsequent requests, without cache, would slow down the application flow. So, this micro-service caches all method/path/query variables/parameters/request body.
The way, we can find out what we are caching it is not simple. Usually, you would cache by a key of the httpRequest.urlWithParams
and only the GET
HTTP method.
To create this cache key, this package is using the object-hash
package, with the following algorithm:
import * as hash from 'object-hash'
const hashOptions = {
algorithm: 'md5',
encoding: 'hex'
}
httpToKey(httpRequest: HttpRequest<any>) {
const key = httpRequest.method + '@' + httpRequest.urlWithParams + '@' + hash(httpRequest.params, hashOptions) + '@' + hash(httpRequest.body, hashOptions)
return key
}
There is room in the future, to restrict to specific methods and add more configurations and functions. If there is a need for this micro-service, it could be enhanced, but for now, it is caching everything, with the exception, when you include the CachingHeaders.NoCache
header into your request, then this request will always hit the server.
https://angular-http-cache-interceptor.corifeus.com
npm i p3x-angular-http-cache-interceptor object-hash
import { NgModule } from '@angular/core';
import { P3XHttpCacheInterceptorModule } from 'p3x-angular-http-cache-interceptor';
@NgModule({
declarations: [
],
imports: [
P3XHttpCacheInterceptorModule,
],
providers: [
],
bootstrap: []
})
export class SomeModule { }
import { P3XHttpCacheInterceptorModule, CachingHeaders, CachingStore } from 'p3x-angular-http-cache-interceptor';
P3XHttpCacheInterceptorModule.forRoot({
// default request is no cache
behavior: CachingHeaders.NoCache,
// if a request has CachingHeaders.Cache header it will cache globally
store: CachingStore.Global,
})
P3XHttpCacheInterceptorModule.forRoot({
// default request is cache
behavior: CachingHeaders.Cache,
// in this config, it will cache not globally, but per module
store: CachingStore.PerModule,
})
With and without cache:
import { Component } from '@angular/core';
import { HttpClient } from "@angular/common/http";
import {MatSnackBar} from "@angular/material/snack-bar";
import { CachingHeaders } from 'p3x-angular-http-cache-interceptor'
@Component({
selector: 'p3x-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.scss']
})
export class AppComponent {
constructor(
private http: HttpClient,
private snack: MatSnackBar,
) {
}
async loadCached() {
try {
const response : any = await this.http.get('https://server.patrikx3.com/api/core/util/random/32').toPromise()
this.snack.open(`Will be always the same: ${response.random}`, 'OK')
} catch(e) {
this.snack.open(`Sorry, error happened, check the console for the error`, 'OK')
console.error(e)
}
}
async loadNonCached() {
try {
const response : any = await this.http.get('https://server.patrikx3.com/api/core/util/random/32', {
headers: {
[CachingHeaders.NoCache]: '1'
}
}).toPromise()
this.snack.open(`Truly random data: ${response.random}`, 'OK')
} catch(e) {
this.snack.open(`Sorry, error happened, check the console for the error`, 'OK')
console.error(e)
}
}
}