angular-cn/aio/src/app/documents/document.service.ts
Tasos Alexiou 356a256909 refactor(docs-infra): enable tslint rules for the angular.io app (#39307)
Signed-off-by: Tasos Alexiou <tasos@arrikto.com>

PR Close #39307
2020-12-17 10:02:38 -08:00

100 lines
3.3 KiB
TypeScript

import { Injectable } from '@angular/core';
import { HttpClient, HttpErrorResponse } from '@angular/common/http';
import { AsyncSubject, Observable, of } from 'rxjs';
import { catchError, switchMap, tap } from 'rxjs/operators';
import { DocumentContents } from './document-contents';
export { DocumentContents } from './document-contents';
import { LocationService } from 'app/shared/location.service';
import { Logger } from 'app/shared/logger.service';
export const FILE_NOT_FOUND_ID = 'file-not-found';
export const FETCHING_ERROR_ID = 'fetching-error';
export const CONTENT_URL_PREFIX = 'generated/';
export const DOC_CONTENT_URL_PREFIX = CONTENT_URL_PREFIX + 'docs/';
const FETCHING_ERROR_CONTENTS = (path: string) => `
<div class="nf-container l-flex-wrap flex-center">
<div class="nf-icon material-icons">error_outline</div>
<div class="nf-response l-flex-wrap">
<h1 class="no-toc">Request for document failed.</h1>
<p>
We are unable to retrieve the "${path}" page at this time.
Please check your connection and try again later.
</p>
</div>
</div>
`;
@Injectable()
export class DocumentService {
private cache = new Map<string, Observable<DocumentContents>>();
currentDocument: Observable<DocumentContents>;
constructor(
private logger: Logger,
private http: HttpClient,
location: LocationService) {
// Whenever the URL changes we try to get the appropriate doc
this.currentDocument = location.currentPath.pipe(switchMap(path => this.getDocument(path)));
}
private getDocument(url: string) {
const id = url || 'index';
this.logger.log('getting document', id);
if (!this.cache.has(id)) {
this.cache.set(id, this.fetchDocument(id));
}
return this.cache.get(id) as Observable<DocumentContents>;
}
private fetchDocument(id: string): Observable<DocumentContents> {
const requestPath = `${DOC_CONTENT_URL_PREFIX}${id}.json`;
const subject = new AsyncSubject<DocumentContents>();
this.logger.log('fetching document from', requestPath);
this.http
.get<DocumentContents>(requestPath, {responseType: 'json'})
.pipe(
tap(data => {
if (!data || typeof data !== 'object') {
this.logger.log('received invalid data:', data);
throw Error('Invalid data');
}
}),
catchError((error: HttpErrorResponse) => {
return error.status === 404 ? this.getFileNotFoundDoc(id) : this.getErrorDoc(id, error);
}),
)
.subscribe(subject);
return subject.asObservable();
}
private getFileNotFoundDoc(id: string): Observable<DocumentContents> {
if (id !== FILE_NOT_FOUND_ID) {
this.logger.error(new Error(`Document file not found at '${id}'`));
// using `getDocument` means that we can fetch the 404 doc contents from the server and cache it
return this.getDocument(FILE_NOT_FOUND_ID);
} else {
return of({
id: FILE_NOT_FOUND_ID,
contents: 'Document not found'
});
}
}
private getErrorDoc(id: string, error: HttpErrorResponse): Observable<DocumentContents> {
this.logger.error(new Error(`Error fetching document '${id}': (${error.message})`));
this.cache.delete(id);
return of({
id: FETCHING_ERROR_ID,
contents: FETCHING_ERROR_CONTENTS(id),
});
}
}