Alter Status Message

Purpose

Allows site administrators to override any Drupal core (or contributed) status messages globally with their own custom messages.
For example, after creating a user, deleting a user, or clearing cache, instead of the default Drupal messages, you can show your custom text.

Features

1. Configuration Form

- Provides an admin UI (/admin/config/system/alter-status-message) where you enter pairs of:

- Original message substring (part of the default Drupal message)

- Custom replacement message

2. Event Subscriber

- Hooks into Drupal’s Response Event (right before the page is sent to the user).

- Reads all status messages queued by Drupal core or other modules.

- For each message:
Checks if it contains any configured “original substring”.
If matched, replaces the entire message with the admin’s custom override.
Re-adds the replaced (or original if no match) message back to Drupal’s messenger service for display.

3. Services

- The event subscriber is registered as a service tagged as event_subscriber so Drupal calls it automatically on every page response.

Benefits & Use Cases

- You do not need to change core or contributed modules — this module acts as a global message interceptor.
- Site builders/admins can tailor all system messages to their preferred tone, branding, or languages without coding.
- Works with any status message, including user creation, deletion, cache clearing, node saves, and more.
- Easy to extend by adding new overrides via admin config anytime.