Cloud Firestore

| Angular | Firebase | TypeScript | Google Cloud Platform | ブログカテゴリ(Firebase) |

• https://firebase.google.com/docs/firestore?hl=ja

データの並べ替え

• https://firebase.google.com/docs/firestore/query-data/order-limit-data?hl=ja

AngularFire

• https://github.com/angular/angularfire/blob/master/docs/firestore/querying-collections.md

Document Fetch

import { Observable } from 'rxjs';
import { AngularFirestore, QuerySnapshot, DocumentSnapshot, DocumentData } from '@angular/fire/firestore';

export const FS_PATH_INFORMATIONS = 'informations/';

constructor(
    public firestore: AngularFirestore
) { }

public getInformations(): Observable<QuerySnapshot<DocumentData>> {
    const path =  `${FS_PATH_INFORMATIONS}`;
    console.log(`get informations..[${path}]`);
    return this.firestore.collection<InformationCard>(path).get();
}

  ngOnInit(): void {
    let outer = this;
    this.bookService.getInformations().subscribe({
      next(p){
        p.forEach(d => {
          outer.infoCards.push(d.data() as InformationCard);
        });
      }
    });
  }

Document Query

/** Firestore Bookshelf Path */
export const FS_PATH_BOOKSHELF = 'bookshelf/v1/users/';

public getBooksInBookshelfQuery(user: User, sortOrder?:SortOrder, lastBook?:Book): Promise<QuerySnapshot<DocumentData>> {
    if (user != null) {
      const pagelimit = 100;
      const path =  `${FS_PATH_BOOKSHELF}${user.uid}/books`;
      console.log(`get book in bookshelf..[${path}] order:${sortOrder}`);
      console.log(`last book entity is.. ${lastBook}`);

      const collection = this.firestore.collection<Book>(path);
      let query = collection.ref.limit(pagelimit);

      if (sortOrder == 'nameAsc') {
        query = query.orderBy('title', 'asc');
        if (lastBook) {
          console.log(`where title >= ${lastBook.title}`);
          query = query
                  .where('title', '>=', lastBook.title)
                  .orderBy('updatedAt', 'desc')
                  .startAfter(lastBook.title, lastBook.updatedAt);
        }
      } else {
        query = query.orderBy('updatedAt', 'desc');
        if (lastBook) {
          console.log(`where updatedAt <= ${lastBook.updatedAt}`);
          query = query
                  .where('updatedAt', '<=', lastBook.updatedAt)
                  .orderBy('title', 'asc')
                  .startAfter(lastBook.updatedAt, lastBook.title);
        }
      }
      return query.get();
    }
  }

    let outer = this;
    this.auth.onAuthStateChanged(async (u) => {
      const query = await this.bookService.getBooksInBookshelfQuery(u, sortOrder, lastBook).then();
      query.forEach((doc) => {
        let book = <Book> doc.data();
        book.documentId = doc.id;
        outer.books.push(book);
      });
    });