feat(config-files): add config files server cache interceptor

Author: Char2sGu

packages/config-files/src/loader.http.server-cache.ts

@@ -0,0 +1,16 @@
+import { HttpInterceptorFn } from '@angular/common/http';
+import { HTTP_SERVER_CACHE_KEY } from '@angularity/core/http';
+
+import { CONFIG_FILE_REQUEST_CONTEXT } from './loader.http';
+
+export const httpServerCacheConfigFilesInterceptor: HttpInterceptorFn = (
+  req,
+  next,
+) => {
+  const context = req.context.get(CONFIG_FILE_REQUEST_CONTEXT);
+  if (!context) return next(req);
+  if (!context.def.id) return next(req);
+  const key = `config-files:${context.def.id}`;
+  req = req.clone({ context: req.context.set(HTTP_SERVER_CACHE_KEY, key) });
+  return next(req);
+};

packages/config-files/src/loader.http.ts

@@ -0,0 +1,65 @@
+import {
+  HttpClient,
+  HttpContext,
+  HttpContextToken,
+} from '@angular/common/http';
+import { inject, Injectable, Injector } from '@angular/core';
+import { pendingUntilEvent } from '@angular/core/rxjs-interop';
+import { catchError, map, Observable, switchMap } from 'rxjs';
+
+import { ConfigFileDefinition } from './definition';
+import { ConfigFileLoader, ConfigFileNotFoundException } from './loader';
+
+/**
+ * Context object that will be supplied to `CONFIG_FILE_REQUEST_CONTEXT`.
+ */
+export interface ConfigFileRequestContext {
+  readonly def: ConfigFileDefinition<unknown, unknown>;
+}
+
+/**
+ * `HttpContextToken` that will be supplied a value in an endpoint request
+ * sent by `HttpClientConfigFileLoader`.
+ */
+export const CONFIG_FILE_REQUEST_CONTEXT =
+  new HttpContextToken<ConfigFileRequestContext | null>(() => null);
+
+/**
+ * Implementation of {@link ConfigFileLoader}
+ * based on Angular's built-in {@link HttpClient}.
+ */
+@Injectable({
+  providedIn: 'root',
+})
+export class HttpClientConfigFileLoader implements ConfigFileLoader {
+  protected httpClient = inject(HttpClient);
+  protected injector = inject(Injector);
+
+  load<T, Schema>(def: ConfigFileDefinition<T, Schema>): Observable<T> {
+    const parser = this.injector.get(def.parser);
+    const validator = this.injector.get(def.validator);
+
+    const context = new HttpContext().set(CONFIG_FILE_REQUEST_CONTEXT, { def });
+    return this.fetch(def.path, context).pipe(
+      map((res) => {
+        if (!res) throw new ConfigFileNotFoundException(def.path);
+        return res;
+      }),
+      switchMap(async (raw) => {
+        const parsed = await parser.parse(raw);
+        await validator.validate(def.schema, parsed);
+        return parsed as T;
+      }),
+      pendingUntilEvent(this.injector),
+    );
+  }
+
+  protected fetch(
+    path: string,
+    context: HttpContext,
+  ): Observable<string | null> {
+    return this.httpClient
+      .get(path, { responseType: 'text', context })
+      .pipe(catchError(() => [null]));
+  }
+}

packages/config-files/src/loader.ts

@@ -1,15 +1,10 @@
-import {
-  HttpClient,
-  HttpContext,
-  HttpContextToken,
-} from '@angular/common/http';
-import { inject, Injectable, Injector } from '@angular/core';
-import { pendingUntilEvent } from '@angular/core/rxjs-interop';
+import { inject, Injectable } from '@angular/core';
 import { Exception } from '@angularity/core';
-import { catchError, map, Observable, switchMap } from 'rxjs';
+import { Observable } from 'rxjs';
 
 import { CacheConfigFiles } from './behaviors';
 import { ConfigFileDefinition } from './definition';
+import { HttpClientConfigFileLoader } from './loader.http';
 
 /**
  * Service for loading configuration files.
@@ -35,48 +30,3 @@ export abstract class ConfigFileLoader {
 }
 
 export class ConfigFileNotFoundException extends Exception {}
-
-/**
- * `HttpContextToken` that will be set to `true` in an endpoint request
- * sent by `HttpClientConfigFileLoader`.
- */
-export const IS_CONFIG_FILE_REQUEST = new HttpContextToken<boolean>(
-  () => false,
-);
-
-/**
- * Implementation of {@link ConfigFileLoader}
- * based on Angular's built-in {@link HttpClient}.
- */
-@Injectable({
-  providedIn: 'root',
-})
-export class HttpClientConfigFileLoader implements ConfigFileLoader {
-  protected httpClient = inject(HttpClient);
-  protected injector = inject(Injector);
-
-  load<T, Schema>(def: ConfigFileDefinition<T, Schema>): Observable<T> {
-    const parser = this.injector.get(def.parser);
-    const validator = this.injector.get(def.validator);
-
-    return this.fetch(def.path).pipe(
-      map((res) => {
-        if (!res) throw new ConfigFileNotFoundException(def.path);
-        return res;
-      }),
-      switchMap(async (raw) => {
-        const parsed = await parser.parse(raw);
-        await validator.validate(def.schema, parsed);
-        return parsed as T;
-      }),
-      pendingUntilEvent(this.injector),
-    );
-  }
-
-  protected fetch(path: string): Observable<string | null> {
-    const context = new HttpContext().set(IS_CONFIG_FILE_REQUEST, true);
-    return this.httpClient
-      .get(path, { responseType: 'text', context })
-      .pipe(catchError(() => [null]));
-  }
-}

packages/config-files/src/public-api.ts

@@ -7,5 +7,7 @@ export * from './behaviors';
 export * from './definition';
 export * from './facade';
 export * from './loader';
+export * from './loader.http';
+export * from './loader.http.server-cache';
 export * from './parser';
 export * from './validator';