firebase CloudFirestore centralized api-service to consume CRUD methods of firebase from a single source of truth

api-service-usage.ts

// POST

createCategory() {
  let data = {
    name: this.programForm.value.categoryName
  }

  let request = this.api.post(this.config.collections.categories_table, data);

  request.then(() => {
    this.programForm.reset();
  })
  .catch((error) => {
    alert(error);
  });
}

// GET ALL

getCategories() {
  let data = this.api.getAll(this.config.collections.categories_table);
}


// GET Single
getCategory(id) {
  this.api.getSingle(this.config.collections.categories_table, id).subscribe(res => {
    console.log(res.data());
  },
  error => {
    alert(error);
  })
}

// update

updateCategory(id) {
  let data = {
    name: "My Place/Community"
  }

  let request = this.api.put(this.config.collections.categories_table, id, data);

  request.then(() => {
    console.log('updated successfully')
  })
  .catch((error) => {
    alert(error);
  });
}


// delete

deleteCategory(id) {
  let request = this.api.delete(this.config.collections.categories_table, id);

  request.then(() => {
    console.log('deleted successfully')
  })
  .catch((error) => {
    alert(error);
  });
}

api.service.ts

import { Injectable } from '@angular/core';
import { ConfigService } from '../../../core/http/config/config.service'
import { AngularFirestore } from '@angular/fire/firestore';
import { Observable } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class ApiService {

  constructor(
    private config: ConfigService,
    private firestore: AngularFirestore,
  ) { }

  post(collection, data) {
    return this.firestore.collection(collection).doc().set(data);
  }

  getAll(collection) {
    let data = [];

    this.firestore.collection(collection).get().subscribe((res) => {
      res.docs.forEach((doc) => {
        data.push({
          id: doc.id,
          ...doc.data() as {}
        });
      });
    });

    return new Observable((observer) => {
      observer.next(data);
    });
  }

  getSingle(collection, id) {
    let data = {};

    return new Observable((observer) => {
      this.firestore.collection(collection).doc(id).get().subscribe(res => {
        data = {
          id: res.id,
          ...res.data() as {}
        }
        
        observer.next(data);
      })
    });
  }

  put(collection, id, data) {
    return this.firestore.collection(collection).doc(id).update(data);
  }

  delete(collection, id) {
    return this.firestore.collection(collection).doc(id).delete();
  }
  
  getWithQuery(collection, key, operator, matchingValue) {
    let data = [];

    return new Observable((observer) => {
      this.firestore.collection(collection, ref => ref.where(key, operator, matchingValue)).get().subscribe(res => {    
        res.forEach(i => {
          data.push({
            id: i.id,
            ...i.data() as {}
          })
        });

        observer.next(data);
      })
    });
  }

}

firebase-ops-vanilla.js

// -------------------------- save - Add new record --------------------------

let data = {
  name: this.programForm.value.categoryName
}

this.firestore.collection("categories").doc().set(data)
.then(() => {
  this.programForm.reset();
})
.catch((error) => {
  alert("Error adding document: " + error);
});


// -------------------------- GET ALL --------------------------

this.firestore.collection(this.config.collections.categories_table).get().subscribe((res) => {
  res.docs.forEach((doc) => {
    this.data.push(doc.data());
  });
});

// -------------------------- GET ALL - mapped with doc Id --------------------------

this.firestore.collection(this.config.collections.categories_table).get().subscribe((res) => {
  res.docs.forEach((doc) => {
    this.data.push({
      id: doc.id,
      ...doc.data() as {}
    });
  });
});

// -------------------------- GET Single --------------------------

this.firestore.collection(collection).doc(id).get().subscribe(res => {
  console.log(res.data());
},
error => {
  alert(error);
})

// -------------------------- PUT --------------------------

this.firestore.collection(collection).doc(id).update(data)
.then(() => {
  console.log('updated successfully')
})
.catch((error) => {
  alert(error);
});

// -------------------------- DELETE --------------------------

this.api.delete(this.config.collections.categories_table, id)
.then(() => {
  console.log('deleted successfully')
})
.catch((error) => {
  alert(error);
});