Exceptions

Every exception the package throws for a call it refuses extends TagsException (a RuntimeException). Present them through four stable methods rather than knowing each class: errorCode() — a snake_case code, public API from 1.0; status() — the HTTP status for a reference in a request body; isNotFound() — the not-found family, which answers 404 when the reference was a path segment; clientMessage() — the translated text a client may see. Messages come from tags::messages in English and Slovak and never name a PHP class:

use RoundlyConsulting\Tags\Exceptions\TagsException;

try {
    $concert->attachTags($request->input('labels', []), 'label');
} catch (TagsException $e) {
    return response()->json(
        ['message' => $e->clientMessage(), 'code' => $e->errorCode()],
        $e->status(),
    );
}

• A missing key presents to clients exactly like a tag of another scope: clientMessage() is the generic “The tag does not exist.” while getMessage() keeps the key for your logs.
• Outside the family: InvalidTagsConfigurationException (configuration the package cannot work with, named by its key — it extends the toolkit’s exception, so catch it beside InvalidConfigurationException) and ReadOnlyTagsRelationException (a LogicException for a write through tags()).