FCM（Bug）：无需OR运算符实现多主题消息推送方案咨询

Got it, let's tackle this FCM OR operator issue you're facing. Since Google's confirmed the bug with || in condition fields, here are some solid, reliable workarounds to target users subscribed to TopicA, TopicB, or TopicC without relying on OR:

• Send separate notifications to each individual topic
  This is the quickest, simplest fix for a small set of topics like your three. Instead of trying to combine them with a broken OR condition, make three distinct FCM API calls—one targeting TopicA, one for TopicB, and one for TopicC.

  • Pros: No extra setup needed, straightforward to implement, and guaranteed to work since single-topic pushes are stable.
  • Cons: You’ll have multiple API requests, but with only three topics, this is negligible for most app traffic volumes.
  • Example FCM HTTP v1 request snippet:

    {
      "message": {
        "topic": "TopicA",
        "notification": {
          "title": "Update Alert",
          "body": "Check out our new content!"
        }
      }
    }
    

  Just replicate this structure for TopicB and TopicC.

• Create an aggregated "parent" topic
  If you regularly need to target users across these three topics, set up a new umbrella topic (e.g., TopicABC). Update your client-side code to automatically subscribe users to this aggregated topic whenever they sign up for any of TopicA, TopicB, or TopicC.

  • For example: When a user taps to subscribe to TopicA, your app runs both subscribeToTopic("TopicA") and subscribeToTopic("TopicABC").
  • Add logic to unsubscribe users from TopicABC only when they’ve unsubscribed from all three original topics.
  • This way, you can send a single notification to TopicABC to reach all relevant users—clean, efficient, and avoids the OR operator entirely.

• Use a compiled list of registration tokens
  If your backend tracks which users are subscribed to each topic, compile all unique registration tokens from TopicA, TopicB, and TopicC into a single list. Then send your notification using the registration_ids field in your FCM request.

  • Note: FCM limits registration_ids to 1000 tokens per request. If your combined list exceeds this, split it into batches of 1000 and send multiple requests.
  • Example snippet:

    {
      "message": {
        "registration_ids": ["user_token_1", "user_token_2", "...", "user_token_1000"],
        "notification": {
          "title": "Update Alert",
          "body": "Check out our new content!"
        }
      }
    }
    

Each of these methods skips the broken OR operator and works reliably while Google resolves the condition field bug. Pick the one that best fits your app’s architecture and how often you need to target this group of users.

内容的提问来源于stack exchange，提问作者S Eleven