fix(firebase): add firestore module

Author: patrickmichalina

src/modules/firebase/common/browser.ts

@@ -0,0 +1,34 @@
+import {
+  TransferState,
+  StateKey,
+  makeStateKey
+} from '@angular/platform-browser'
+import { HttpParams } from '@angular/common/http'
+
+export function removeHttpInterceptorCache<T>(ts: TransferState, key: string) {
+  return function(val: T) {
+    ts.remove(makeStateKey<string>(`G.${key}`))
+  }
+}
+
+export function cacheInStateTransfer<T>(
+  ts: TransferState,
+  key: StateKey<string>
+) {
+  return function(val: T) {
+    ts.set(key, val)
+  }
+}
+
+export function getParams(fromObject = {} as any) {
+  return new HttpParams({
+    fromObject: Object.keys(fromObject).reduce((acc, curr) => {
+      return fromObject[curr]
+        ? {
+            ...acc,
+            [curr]: fromObject[curr]
+          }
+        : { ...acc }
+    }, {})
+  })
+}

src/modules/firebase/common/server.ts

@@ -0,0 +1,34 @@
+import { InjectionToken } from '@angular/core'
+import { createHash } from 'crypto'
+import { HttpParams } from '@angular/common/http'
+
+export interface LruCache {
+  readonly get: <T>(key: string) => T
+  readonly set: <T>(key: string, value: T) => T
+}
+
+export const LRU_CACHE = new InjectionToken<LruCache>('fng.lru')
+export const FIREBASE_USER_AUTH_TOKEN = new InjectionToken<string>(
+  'fng.fb.svr.usr.auth'
+)
+
+function sha256(data: string) {
+  return createHash('sha256')
+    .update(data)
+    .digest('base64')
+}
+
+export function attemptToCacheInLru(key: string, lru?: LruCache) {
+  return function(response?: any) {
+    lru && response && lru.set(sha256(key), response)
+  }
+}
+
+export function attemptToGetLruCachedValue<T>(key: string, lru?: LruCache) {
+  return lru && lru.get<T>(sha256(key))
+}
+
+export function getFullUrl(base: string, params: HttpParams) {
+  const stringifiedParams = params.toString()
+  return stringifiedParams ? `${base}?${params.toString()}` : base
+}

src/modules/firebase/firestore/browser.firebase.fs.common.ts

@@ -0,0 +1,14 @@
+import { AngularFirestore, QueryFn } from 'angularfire2/firestore'
+import { Observable } from 'rxjs'
+
+export interface IUniversalFirestoreService {
+  readonly universalDoc: <T>(path: string) => Observable<T | undefined>
+  readonly universalCollection: <T>(
+    path: string,
+    queryFn?: QueryFn
+  ) => Observable<ReadonlyArray<T>>
+}
+
+export function extractFsHostFromLib(affs: AngularFirestore) {
+  return (affs.firestore.app.options as any).projectId
+}

src/modules/firebase/firestore/browser.firebase.fs.module.ts

@@ -0,0 +1,30 @@
+import {
+  NgModule,
+  ModuleWithProviders,
+  Optional,
+  SkipSelf
+} from '@angular/core'
+import { UniversalFirestoreService } from './browser.firebase.fs.service'
+
+// tslint:disable-next-line:no-class
+@NgModule()
+export class FirebaseFsBrowserModule {
+  static forRoot(): ModuleWithProviders {
+    return {
+      ngModule: FirebaseFsBrowserModule,
+      providers: [UniversalFirestoreService]
+    }
+  }
+
+  constructor(
+    @Optional()
+    @SkipSelf()
+    parentModule: FirebaseFsBrowserModule
+  ) {
+    // tslint:disable-next-line:no-if-statement
+    if (parentModule)
+      throw new Error(
+        'FirebaseFsBrowserModule already loaded. Import in root module only.'
+      )
+  }
+}

src/modules/firebase/firestore/browser.firebase.fs.service.ts

@@ -0,0 +1,82 @@
+import {
+  catchError,
+  distinctUntilChanged,
+  startWith,
+  filter,
+  take
+} from 'rxjs/operators'
+import { Injectable, ApplicationRef } from '@angular/core'
+import { TransferState } from '@angular/platform-browser'
+import { sha1 } from 'object-hash'
+import { of } from 'rxjs'
+import { AngularFirestore, QueryFn } from 'angularfire2/firestore'
+import {
+  IUniversalFirestoreService,
+  extractFsHostFromLib
+} from './browser.firebase.fs.common'
+import {
+  makeFirestoreStateTransferKey,
+  constructFsUrl
+} from './server.firebase.fs.common'
+
+// tslint:disable:no-this
+// tslint:disable-next-line:no-class
+@Injectable()
+export class UniversalFirestoreService implements IUniversalFirestoreService {
+  constructor(
+    private ts: TransferState,
+    public afs: AngularFirestore,
+    appRef: ApplicationRef
+  ) {
+    appRef.isStable
+      .pipe(
+        filter(Boolean),
+        take(1)
+      )
+      .subscribe(() => this.turnOffCache())
+  }
+
+  // tslint:disable-next-line:readonly-keyword
+  private readFromCache = true
+
+  private turnOffCache() {
+    // tslint:disable-next-line:no-object-mutation
+    this.readFromCache = false
+  }
+
+  universalDoc<T>(path: string) {
+    const url = constructFsUrl(extractFsHostFromLib(this.afs), path)
+    const cached = this.ts.get<T | undefined>(
+      makeFirestoreStateTransferKey(url),
+      undefined
+    )
+
+    const base = this.afs.doc<T>(path).valueChanges()
+
+    return this.readFromCache && cached
+      ? base.pipe(
+          startWith(cached as T),
+          distinctUntilChanged((x, y) => sha1(x) === sha1(y)),
+          catchError(err => of(undefined))
+        )
+      : base
+  }
+
+  universalCollection<T>(path: string, queryFn?: QueryFn) {
+    const url = constructFsUrl(extractFsHostFromLib(this.afs), path, true)
+
+    const cached = this.ts.get<ReadonlyArray<T>>(
+      makeFirestoreStateTransferKey(url),
+      []
+    )
+    const base = this.afs.collection<T>(path, queryFn).valueChanges()
+
+    return this.readFromCache && cached.length > 0
+      ? base.pipe(
+          startWith(cached),
+          distinctUntilChanged((x, y) => sha1(x) === sha1(y)),
+          catchError(err => of(cached))
+        )
+      : base
+  }
+}

src/modules/firebase/firestore/server.firebase.fs.common.ts

@@ -0,0 +1,11 @@
+import { makeStateKey } from '@angular/platform-browser'
+
+export function makeFirestoreStateTransferKey(fullUrl: string) {
+  return makeStateKey<string>(`FS.${fullUrl}`)
+}
+
+export function constructFsUrl(host: string, path?: string, runQuery = false) {
+  return `https://firestore.googleapis.com/v1beta1/projects/${host}/databases/(default)/documents${
+    runQuery ? ':runQuery' : '/' + path
+  }`
+}

src/modules/firebase/firestore/server.firebase.fs.module.ts

@@ -0,0 +1,36 @@
+import {
+  NgModule,
+  ModuleWithProviders,
+  Optional,
+  SkipSelf
+} from '@angular/core'
+import { UniversalFirestoreService } from './browser.firebase.fs.service'
+import { ServerUniversalFirestoreService } from './server.firebase.fs.service'
+
+// tslint:disable-next-line:no-class
+@NgModule()
+export class FirebaseFsServerModule {
+  static forRoot(): ModuleWithProviders {
+    return {
+      ngModule: FirebaseFsServerModule,
+      providers: [
+        {
+          provide: UniversalFirestoreService,
+          useClass: ServerUniversalFirestoreService
+        }
+      ]
+    }
+  }
+
+  constructor(
+    @Optional()
+    @SkipSelf()
+    parentModule: FirebaseFsServerModule
+  ) {
+    // tslint:disable-next-line:no-if-statement
+    if (parentModule)
+      throw new Error(
+        'FirebaseFsServerModule already loaded. Import in root module only.'
+      )
+  }
+}