/
save_transaction_document_update_conditional.go
54 lines (47 loc) · 1.49 KB
/
save_transaction_document_update_conditional.go
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// Copyright 2023 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package firestore
// [START firestore_transaction_document_update_conditional]
import (
"context"
"errors"
"log"
"cloud.google.com/go/firestore"
)
func infoTransaction(ctx context.Context, client *firestore.Client) error {
ref := client.Collection("cities").Doc("SF")
err := client.RunTransaction(ctx, func(ctx context.Context, tx *firestore.Transaction) error {
doc, err := tx.Get(ref)
if err != nil {
return err
}
pop, err := doc.DataAt("population")
if err != nil {
return err
}
newpop := pop.(int64) + 1
if newpop <= 1000000 {
return tx.Set(ref, map[string]interface{}{
"population": pop.(int64) + 1,
}, firestore.MergeAll)
}
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
}
// [END firestore_transaction_document_update_conditional]