Tags

Introduction

Tags are an optional part of an IRC message. If present, they are the first part of a message and prefixed with an @. They come as a string of key-value pairs and contain meta data for the message. Depending on the type of message, different kind of tags can be present. Here is an example for a message with tags:

@badges=;color=#DAA520;display-name=domsson;emotes=;message-id=2;thread-id=1234_5678;turbo=0;user-id=123456;user-type= :[email protected] WHISPER kaulmate :hey kaul!

If a message contains tags, these will be handed to your callback function as the char **tags member within the twirc_event_t *evt struct, where twirc_event_t has two members, key and value. The value will point to an empty string if the tag did not have a value, as for example the badges tag in the example message above.

Getting tags

In your event handler, you can use the twirc_get_tag() function to extract a specified tag if that tag was present. If there was no tag with the specified key, it will return NULL. Example:

void handle_whisper(twirc_state_t *s, twirc_event_t *evt)
{
        twirc_tag_t *display_name = twirc_get_tag(evt->tags, "display-name");
        twirc_tag_t *message_id   = twirc_get_tag(evt->tags, "message-id");
	fprintf(stdout, "*** Whisper from %s (message id %s): %s\n",
			display_name == NULL ? evt->origin : display_name->value,
			message_id   == NULL ? "n/a"       : message_id->value,
                        evt->message);
}

The signature of the method is as follows:

twirc_tag_t *twirc_get_tag(twirc_tag_t **tags, const char *key);

Alternatively, as a short-cut, you can use twirc_get_tag_value(), which will give you the pointer to the requested tag's value directly, saving you a line of code. Again, if the specified tag does not exist, NULL will be returned. The signature is as follows:

char const *twirg_get_tag_value(twirc_tag_t **tags, const char *key);