docs(samples): passing data out of firestore transaction in go

GoogleCloudPlatform · Jul 24, 2024 · 82bdfd0 · 82bdfd0
1 parent d60ee3d
commit 82bdfd0
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Showing 2 changed files with 10 additions and 6 deletions.
diff --git a/firestore/save_test.go b/firestore/save_test.go
@@ -105,7 +105,7 @@ func TestSave(t *testing.T) {
  if err = runSimpleTransaction(ctx, client); err != nil {
  t.Fatalf("runSimpleTransaction: %v", err)
  }
- if err = infoTransaction(ctx, client); err != nil {
+ if _, err = infoTransaction(ctx, client); err != nil {
  t.Fatalf("infoTransaction: %v", err)
  }
  if err = batchWrite(ctx, client); err != nil {

diff --git a/firestore/save_transaction_document_update_conditional.go b/firestore/save_transaction_document_update_conditional.go
@@ -24,7 +24,8 @@ import (
  "cloud.google.com/go/firestore"
 )
 
-func infoTransaction(ctx context.Context, client *firestore.Client) error {
+func infoTransaction(ctx context.Context, client *firestore.Client) (int64, error) {
+ var updatedPop int64
  ref := client.Collection("cities").Doc("SF")
  err := client.RunTransaction(ctx, func(ctx context.Context, tx *firestore.Transaction) error {
  doc, err := tx.Get(ref)
@@ -37,18 +38,21 @@ func infoTransaction(ctx context.Context, client *firestore.Client) error {
  }
  newpop := pop.(int64) + 1
  if newpop <= 1000000 {
- return tx.Set(ref, map[string]interface{}{
- "population": pop.(int64) + 1,
+ err := tx.Set(ref, map[string]interface{}{
+ "population": newpop,
  }, firestore.MergeAll)
+ if err == nil {
+ updatedPop = newpop
+ }
+ return err
  }
  return errors.New("population is too big")
  })
  if err != nil {
  // Handle any errors in an appropriate way, such as returning them.
  log.Printf("An error has occurred: %s", err)
  }
-
- return err
+ return updatedPop, err
 }
 
 // [END firestore_transaction_document_update_conditional]