Firebase firestore reactive database mixins

- TypeSafe, Reactive
- Firebase cloud function and AWS Lambda compatability

#### Install
``bash
npm i @rxdi/firestore
`

#### Initialize firebase module
`typescript

import { Module } from '@rxdi/core';
import { FirebaseModule } from '@rxdi/firestore';
import * as functions from 'firebase-functions';
import * as admin from 'firebase-admin';

@Module({
imports: [
FirebaseModule.forRoot({
projectId: 'your-firebase-project-id',
credential: process.env.IS_NOT_LAMBDA
? admin.credential.applicationDefault()
: functions.config().firebase
}),
],
})
export class AppModule {}
`

#### Set environment variable GOOGLE_APPLICATION_CREDENTIALS representing your Firebase configuration

> More info can be found here https://firebase.google.com/docs/admin/setup

`bash
export GOOGLE_APPLICATION_CREDENTIALS="/home/user/Downloads/service-account-file.json"
`

`json
{
"type": "service_account",
"project_id": "",
"private_key_id": "",
"private_key": "-----BEGIN PRIVATE KEY-----\n-----END PRIVATE KEY-----\n",
"client_email": "",
"client_id": "",
"auth_uri": "https://accounts.google.com/o/oauth2/auth",
"token_uri": "https://oauth2.googleapis.com/token",
"auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
"client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/firebase-adminsdk-eb9yl%40xx-xx-xx.iam.gserviceaccount.com"
}
`

When executing admin.credential.applicationDefault() firebase will get path from GOOGLE_APPLICATION_CREDENTIALS and try to read and load the credentials.

#### Define your reactive firestore collections


`typescript
import { Injectable, Inject } from '@rxdi/core';
import { GenericFirebaseModel, Firestore } from '@rxdi/firestore';

interface IUserType {
id: string;
displayName: string;
email: string;
}

@Injectable()
export class UserCollection extends GenericFirebaseModel {
constructor(@Inject(Firestore) firestore: Firestore) {
super('users', firestore);
}
}

`

#### import UserCollection inside AppModule as a provider/service

`typescript
import { Module } from '@rxdi/core';
import { FirebaseModule } from '@rxdi/firestore';
import { ModelsModule } from '../database/models.module';
import * as functions from 'firebase-functions';
import * as admin from 'firebase-admin';
import { UserCollection } from './models/user';

@Module({
imports: [
FirebaseModule.forRoot({
projectId: 'your-firebase-project-id',
credential: process.env.IS_NOT_LAMBDA
? admin.credential.applicationDefault()
: functions.config().firebase
}),
],
providers: [UserCollection]
})
export class AppModule {}

`


#### Use created mixins


`typescript
import { Injectable } from '@rxdi/core';
import { UserCollection } from '../models/user';

@Injectable()
export class UserCollectionService {
constructor(
private userCollection: UserCollection
) {}
}

`

#### Mixins provide the following instance methods

`typescript
import { CollectionReference, Firestore } from '@google-cloud/firestore';
import { StaticMethods } from './static-mixins';
export declare class FirestoreCollection extends StaticMethods {
private collection;
constructor(collectionName: string, firestore: Firestore);
getCollectionRef(): CollectionReference;
getFirestoreRef(): Firestore;
getRef(doc: string): FirebaseFirestore.DocumentReference;
create(payload: T, doc?: string): Promise;
get(doc: string): Promise;
delete(doc: string): Promise;
update(doc: string, payload: T): Promise;
findAll(where?: T): Promise;
find(payload: T): Promise;
build(payload: T): T;
}
`


#### Mixins provide also static methods

`typescript
import { FirestoreCollection } from './mixins';
export declare class StaticMethods {
static create(payload: T, doc?: string): Promise;
static getCollectionRef(): FirebaseFirestore.CollectionReference;
static getFirestoreRef(): FirebaseFirestore.Firestore;
static getRef(doc: string): FirebaseFirestore.DocumentReference;
static get(doc: string): Promise;
static delete(doc: string): Promise;
static update(doc: string, payload: T): Promise;
static findAll(where?: T): Promise;
static find(payload: T): Promise;
static build(payload: T): T;
}
``