# Introduction

# Usage

Rooms joined and the associated nickname is kept in a table field

`rooms_joined` on the users session.

An example:

``` lua

local jid_bare = require"util.jid".bare;

module:hook("message/full", function (event)

    local stanza = event.stanza;

    local session = prosody.full_sessions[stanza.attr.to];

    if not session then

        return -- No such session

    end

    local joined_rooms = session.joined_rooms;

    if not joined_rooms then

        return -- This session hasn't joined any rooms at all

    end

    -- joined_rooms is a map of room JID -> room nickname

    local nickname = joined_rooms[jid_bare(stanza.attr.from)];

    if nickname then

        session.log("info", "Got a MUC message from %s", stanza.attr.from);

        local body = stanza:get_child_text("body");

        if body and body:find(nickname, 1, true) then

            session.log("info", "The message contains my nickname!");

        end

    end

end);

```