Author: Firebase (https://firebase.google.com)

Description: Translates strings written to a Cloud Firestore collection into multiple languages (uses Cloud Translation API).

Details: Use this extension to translate strings (for example, text messages) written to a Cloud Firestore collection.

This extension listens to your specified Cloud Firestore collection. If you add a string to a specified field in any document within that collection, this extension:

• Translates the string into your specified target language(s); the source language of the string is automatically detected.
• Adds the translation(s) of the string to a separate specified field in the same document.

You specify the desired target languages using ISO-639-1 codes. You can find a list of valid languages and their corresponding codes in the Cloud Translation API documentation.

If the original non-translated field of the document is updated, then the translations will be automatically updated, as well.

To translate multiple collections, install this extension multiple times, specifying a different collection path each time. There is currently no limit on how many instances of an extension you can install.

To translate multiple fields, store a map of input strings in the input field:

admin.firestore().collection('translations').add({
  first: "My name is Bob",
  second: "Hello, friend"
})

To translate text into multiple languages, set the languages parameter to a comma-separated list of languages, such as en,fr,de. See the supported languages list.

Before installing this extension, make sure that you've set up a Cloud Firestore database in your Firebase project.

To install an extension, your project must be on the Blaze (pay as you go) plan

• You will be charged a small amount (typically around $0.01/month) for the Firebase resources required by this extension (even if it is not used).
• This extension uses other Firebase and Google Cloud Platform services, which have associated charges if you exceed the service’s no-cost tier:
  • Cloud Translation API
  • Cloud Firestore
  • Cloud Functions (Node.js 10+ runtime. See FAQs)

Configuration Parameters:

• Target languages for translations, as a comma-separated list: Into which target languages do you want to translate new strings? The languages are identified using ISO-639-1 codes in a comma-separated list, for example: en,es,de,fr. For these codes, visit the supported languages list.

• Collection path: What is the path to the collection that contains the strings that you want to translate?

• Input field name: What is the name of the field that contains the string that you want to translate?

• Translations output field name: What is the name of the field where you want to store your translations?

• Languages field name: What is the name of the field that contains the languages that you want to translate into? This field is optional. If you don't specify it, the extension will use the languages specified in the LANGUAGES parameter.

Cloud Functions:

• fstranslate: Listens for writes of new strings to your specified Cloud Firestore collection, translates the strings, then writes the translated strings back to the same document.

• fstranslatebackfill: Searches your specified Cloud Firestore collection for existing documents, translates the strings into any missing languages, then writes the translated strings back to the same document.

APIs Used:

• translate.googleapis.com (Reason: To use Google Translate to translate strings into your specified target languages.)

Access Required:

This extension will operate with the following project IAM roles:

• datastore.user (Reason: Allows the extension to write translated strings to Cloud Firestore.)