firebase-php | Unofficial Firebase Admin SDK for PHP | Authentication library

The best I know of the documentation on sending messages to topics, which contains this section on conditions:

To send a message to a combination of topics, specify a condition, which is a boolean expression that specifies the target topics. For example, the following condition will send messages to devices that are subscribed to TopicA and either TopicB or TopicC:

You can use the following methods:

Firebase Authentication code runs client-side, so in the browser or in the native app. The PHP code that you have runs on the server, where you can't sign in a user. The server-side code itself runs with administrative privileges, as you configure it with a service account.

If you are interacting with the database directly from the client-side code too, you'll want to include the JavaScript SDK in your client-side, and sign in the user there as shown in the documentation.

If you're interacting with the database from the server-side PHP code, that should already work as using a service account means your code bypasses the security rules. If this isn't working for you, please edit your question to show how you configure the SDK.

There is no public API to get a list of topic names from Firebase, nor is there a way to hook into the subscription mechanism.

Your best bet is to simply make two calls when a user subscribes to a topic: one to Firebase, and one to your own backend API that keeps a list of active topics/conditions.

This seems to be a problem with the virtual box filesystem. I created an issue to composer and hopefully more insight will be gained.

https://github.com/composer/package-versions-deprecated/issues/21

You have installed v5.0.0 of the Firebase Admin SDK for PHP, but the tutorial you followed is for a 4.x version.

This is an issue that happens so often that it has its own section in the "Troubleshooting" section in the SDK's documentation.

With v5.x, the correct way to initialize a Firebase component is:

The only way to get multiple (but not all) child nodes with a single request is with a query. But you can't pass multiple IDs in a query.

Simply put: Firebase Realtime Database does not support a WHERE $key IN [key1, key2, key3] type query that you want to do here. You will have to perform a separate request for each ID.

This is not a limitation of the PHP SDK (or any other Firebase SDK) - Realtime Database queries only support sorting by one dimension. The SDK just saves you from making a request and getting an error or unexpected results.

If you need to sort by multiple dimensions, you either have to do it in your (PHP) code, or create a compound key/field in the database that you can sort by.

You could do the latter for example by introducing a new field in which the value is active_ or inactive_.

Querying by this field in ascending order would give you the active users sorted by email first, followed by the inactive users sorted by email.

Querying by this field in descending order would give you the inactive users sorted by email first, followed by the active users sorted by email.

Since your deployed application already has a composer.lock file generated from App Engine deployment and by default, App Engine caches fetched dependencies to reduce build times. It will prevents you from automatically getting the latest versions of your dependencies and you will encounter the error:

You are using an outdated version of Composer

To resolve the issue, run command composer install locally to pin your dependencies to their current version and to have a composer.lock and composer update if composer.lock is existing. Then deploy using the command 'gcloud beta app deploy --no-cache' to install an uncached version of the dependency.