Batch and Transaction Operation in FireStore #667

Author: EddyVerbruggen

CHANGELOG.md

@@ -3,6 +3,10 @@
 [Firebase iOS SDK Changelog](https://firebase.google.com/support/release-notes/ios)
 [Firebase Android SDK Changelog](https://firebase.google.com/support/release-notes/android)
 
+## 6.5.0 (2018, August ?)
+[Fixes & Enhancements](https://github.com/EddyVerbruggen/nativescript-plugin-firebase/milestone/65?closed=1)
+
+
 ## 6.4.1 (2018, July 28)
 [Fixes & Enhancements](https://github.com/EddyVerbruggen/nativescript-plugin-firebase/milestone/64?closed=1)
 

demo-ng/app/tabs/firestore/firestore.component.html

@@ -25,7 +25,7 @@
     <Button text="Where, Order, Limit" (tap)="firestoreWhereOrderLimit()" class="button"></Button>
     <Button text="Where array_contains" (tap)="firestoreWhereCityHasALake()" class="button"></Button>
     <Button text="Delete" (tap)="firestoreDelete()" class="button"></Button>
-    <!--<Button text="Transactional update" (tap)="transactionalUpdate()" class="button"></Button>-->
+    <Button text="Transactional update (iOS)" (tap)="transactionalUpdate()" class="button"></Button>
     <Button text="Write batch" (tap)="writeBatch()" class="button"></Button>
   </StackLayout>
 </ScrollView>

demo-ng/app/tabs/firestore/firestore.component.ts

@@ -286,13 +286,25 @@ export class FirestoreComponent {
     const path = "/companies";
     firebase.database().ref(path)
         .once("value")
-        .then(result => {
-          console.log(`${result.key} => ${JSON.stringify(result.val())}`);
-        })
+        .then(result => console.log(`${result.key} => ${JSON.stringify(result.val())}`))
         .catch(error => console.log("doWebGetValueForCompanies error: " + error));
   }
 
-  /*
+  public writeBatch(): void {
+    // one batch can update multiple docs
+    const sfDocRef: firestore.DocumentReference = firebase.firestore().collection("cities").doc("SF");
+    const sacDocRef: firestore.DocumentReference = firebase.firestore().collection("cities").doc("SAC");
+
+    firebase.firestore().batch()
+        .set(sfDocRef, {capital: false}, {merge: true})
+        // .delete(sfDocRef) // Want to verify batches are atomic? With this line enabled, the next line will fail and the entire batch is rolled back correctly 👍
+        .update(sfDocRef, {population: 860100})
+        .update(sacDocRef, {population: 6500100})
+        .commit()
+        .then(() => console.log(`Batch successfully committed`))
+        .catch(error => console.log("Batch error: " + error));
+  }
+
   public transactionalUpdate(): void {
     const sfDocRef: firestore.DocumentReference = firebase.firestore().collection("cities").doc("SF");
 
@@ -304,7 +316,6 @@ export class FirestoreComponent {
         const newPopulation = sfDoc.data().population + 1;
         console.log(`Updating city 'SF' to a new population of: ${newPopulation}, and flipping the 'capital' state to ${sfDoc.data().capital}.`);
 
-        // this should fail
         transaction
             .set(sfDocRef, {capital: !sfDoc.data().capital}, {merge: true})
             // .delete(sfDocRef) // with this line enabled, the next line will fail and the entire tx is rolled back 👍
@@ -315,20 +326,4 @@ export class FirestoreComponent {
         .then(() => console.log(`Transaction successfully committed`))
         .catch(error => console.log("doTransaction error: " + error));
   }
-  */
-
-  public writeBatch(): void {
-    // one batch can update multiple docs
-    const sfDocRef: firestore.DocumentReference = firebase.firestore().collection("cities").doc("SF");
-    const sacDocRef: firestore.DocumentReference = firebase.firestore().collection("cities").doc("SAC");
-
-    firebase.firestore().batch()
-        .set(sfDocRef, {capital: false}, {merge: true})
-        // .delete(sfDocRef) // Want to verify batches are atomic? With this line enabled, the next line will fail and the entire batch is rolled back correctly 👍
-        .update(sfDocRef, {population: 860100})
-        .update(sacDocRef, {population: 6500100})
-        .commit()
-        .then(() => console.log(`Batch successfully committed`))
-        .catch(error => console.log("Batch error: " + error));
-  }
 }

docs/FIRESTORE.md

@@ -237,7 +237,7 @@ query
     });
 ```
 
-### `batch()`
+### Batched Writes: `batch()`
 To perform a (mixed) sequence of `set`, `update`, and/or `delete` operations in an atomic fashion
 (everything is rolled back if 1 operation fails), use the `batch` feature.
 
@@ -263,5 +263,32 @@ firebase.firestore().batch()
     .update(sanFranciscoDocumentReference, {population: 7})
     .commit()
     .then(() => console.log("Batch successfully committed"))
-    .catch(error => console.log("Batch error: " + error));
+    .catch(error => console.log(`Batch error: ${error}`));
+```
+
+### Transactional Updates: `runTransaction()` (iOS only)
+> There's a technical hurdle which prevents this from working on Android.
+
+In contrast to `batch` you can `runTransaction` to also be able to use `get`, but only use `get`
+before calling `set`, `update`, or `delete` (or the transaction will fail).
+
+```typescript
+const sanFranciscoDocumentReference: firestore.DocumentReference = firebase.firestore().collection("cities").doc("SF");
+
+firebase.firestore().runTransaction(transaction => {
+  const doc = transaction.get(sanFranciscoDocumentReference);
+  if (!doc.exists) {
+    console.log("City SF doesn't exist");
+  } else {
+    const newPopulation = doc.data().population + 1;
+    console.log(`Updating city 'SF' to a new population of: ${newPopulation}, and flipping the 'capital' state to ${sfDoc.data().capital}.`);
+
+    transaction
+        .set(sanFranciscoDocumentReference, {capital: !doc.data().capital}, {merge: true})
+        .update(sanFranciscoDocumentReference, {population: newPopulation})
+  }
+  return null;
+})
+   .then(() => console.log("Transaction successfully committed"))
+   .catch(error => console.log(`Transaction error: ${error}`));
 ```

src/app/firestore/index.ts

@@ -16,9 +16,9 @@ export module firestore {
       return firebase.firestore.GeoPoint(latitude, longitude);
     }
 
-    // runTransaction<T>(updateFunction: (transaction: firebase.firestore.Transaction) => Promise<any>): Promise<void> {
-    //   return firebase.firestore.runTransaction(updateFunction);
-    // }
+    runTransaction<T>(updateFunction: (transaction: firebase.firestore.Transaction) => Promise<any>): Promise<void> {
+      return firebase.firestore.runTransaction(updateFunction);
+    }
 
     batch(): firebase.firestore.WriteBatch {
       return firebase.firestore.batch();

src/firebase.android.ts

@@ -2161,6 +2161,13 @@ firebase.firestore.batch = (): firestore.WriteBatch => {
   return batch;
 };
 
+firebase.firestore.runTransaction = (updateFunction: (transaction: firestore.Transaction) => Promise<any>): Promise<void> => {
+  return new Promise((resolve, reject) => {
+    // Why? See the note in the commented 'runTransaction' function below.
+    reject("Not supported on Android. If you need a x-platform implementation, use 'batch' instead.");
+  });
+};
+
 /*
 class FirestoreTransaction implements firestore.Transaction {
 
@@ -2172,7 +2179,6 @@ class FirestoreTransaction implements firestore.Transaction {
   };
 
   public set = (documentRef: firestore.DocumentReference, data: firestore.DocumentData, options?: firestore.SetOptions): firestore.Transaction => {
-    console.log(">>> in tx.set");
     if (options && options.merge) {
       this.nativeTransaction.set(documentRef.android, firebase.toValue(data), com.google.firebase.firestore.SetOptions.merge());
     } else {
@@ -2182,13 +2188,11 @@ class FirestoreTransaction implements firestore.Transaction {
   };
 
   public update = (documentRef: firestore.DocumentReference, data: firestore.UpdateData): firestore.Transaction => {
-    console.log(">>> in tx.update");
     this.nativeTransaction.update(documentRef.android, firebase.toValue(data));
     return this;
   };
 
   public delete = (documentRef: firestore.DocumentReference): firestore.Transaction => {
-    console.log(">>> in tx.delete");
     this.nativeTransaction.delete(documentRef.android);
     return this;
   }
@@ -2209,49 +2213,16 @@ firebase.firestore.runTransaction = (updateFunction: (transaction: firestore.Tra
       }
     });
 
-    const l = new java.util.ArrayList();
-    l.add("foooo");
-    l.add("barrr");
-    org.nativescript.plugins.firebase.FirebaseFirestore.STATE = onSuccessListenert; // for this assignment to 'stick', this needs to be a real Java object
-    org.nativescript.plugins.firebase.FirebaseFirestore.UPDATE_FUNCTION = updateFunction;
-    console.log(">>> STATE: " + org.nativescript.plugins.firebase.FirebaseFirestore.STATE);
-    console.log(">>> UPDATE_FUNCTION: " + org.nativescript.plugins.firebase.FirebaseFirestore.UPDATE_FUNCTION);
-
-    let worker;
-    if (global['TNS_WEBPACK']) {
-      const WorkerScript = require('nativescript-worker-loader!./android-firestoretx-worker.js');
-      worker = new WorkerScript();
-    } else {
-      worker = new Worker('./android-firestoretx-worker.js');
-    }
-
-    (<any>global).theUpdateFunction = updateFunction;
-
-    worker.onmessage = msg => {
-      console.log(">>> msg from worker, stringified: " + JSON.stringify(msg));
-    };
-
-    worker.onerror = err => {
-      console.log(">>> worker err: " + JSON.stringify(err));
-    };
-
-    worker.postMessage({
-      in: "innn",
-      someArray: l,
-      onSuccessListenert: onSuccessListenert
-      // updateFunction: updateFunction
-    });
-
     const onSuccessListener = new com.google.android.gms.tasks.OnSuccessListener({
-      onSuccess: resolve // TODO does this syntax work? if so: refactor other instances... otherwise use: onSuccess: () => resolve()
+      onSuccess: () => resolve()
     });
 
     const onFailureListener = new com.google.android.gms.tasks.OnFailureListener({
       onFailure: exception => reject(exception.getMessage())
     });
 
-    // TODO apply is called from java to js, so that makes it run on the main/UI thread.. so doesn't work
-    // .. can we share native objects via appcontext (for a worker)?
+    // NOTE: Here's the problem: 'apply' is called from java to js, so that makes it run on the main/UI thread,
+    // which is not allowed by Firebase.. so doesn't work in {N}
     const txFunction = new com.google.firebase.firestore.Transaction.Function({
       apply: (nativeTransaction: com.google.firebase.firestore.Transaction) => {
         const tx = new firebase.firestore.Transaction(nativeTransaction);
@@ -2262,8 +2233,6 @@ firebase.firestore.runTransaction = (updateFunction: (transaction: firestore.Tra
     com.google.firebase.firestore.FirebaseFirestore.getInstance().runTransaction(txFunction)
         .addOnSuccessListener(onSuccessListener)
         .addOnFailureListener(onFailureListener);
-
-    // org.nativescript.plugins.firebase.FirebaseFirestore.runTransaction(txFunction, onSuccessListener, onFailureListener);
   });
 };
 */

src/firebase.d.ts

@@ -771,15 +771,13 @@ export namespace firestore {
     static documentId(): FieldPath;
   }
 
-  /*
   export interface Transaction {
     get(documentRef: DocumentReference): DocumentSnapshot;
     set(documentRef: DocumentReference, data: DocumentData, options?: SetOptions): Transaction;
     update(documentRef: DocumentReference, data: UpdateData): Transaction;
     update(documentRef: DocumentReference, field: string | FieldPath, value: any, ...moreFieldsAndValues: any[]): Transaction;
     delete(documentRef: DocumentReference): Transaction;
   }
-  */
 
   export interface WriteBatch {
     set(documentRef: DocumentReference, data: DocumentData, options?: SetOptions): WriteBatch;
@@ -813,7 +811,7 @@ export namespace firestore {
 
   function update(collectionPath: string, documentPath: string, document: any): Promise<void>;
 
-  // function runTransaction(updateFunction: (transaction: firestore.Transaction) => Promise<any>): Promise<void>;
+  function runTransaction(updateFunction: (transaction: firestore.Transaction) => Promise<any>): Promise<void>;
 
   function batch(): firestore.WriteBatch;
 }

src/firebase.ios.ts

@@ -2146,7 +2146,6 @@ firebase.firestore.batch = (): firestore.WriteBatch => {
   return new firebase.firestore.WriteBatch(FIRFirestore.firestore().batch());
 };
 
-/*
 firebase.firestore.Transaction = (nativeTransaction: FIRTransaction): firestore.Transaction => {
   class FirestoreTransaction implements firestore.Transaction {
     constructor() {
@@ -2188,7 +2187,6 @@ firebase.firestore.runTransaction = (updateFunction: (transaction: firestore.Tra
         (result, error: NSError) => error ? reject(error.localizedDescription) : resolve());
   });
 };
-*/
 
 firebase.firestore.collection = (collectionPath: string): firestore.CollectionReference => {
   try {