iterations-live-website/kiwi-irc/client/src/models/memberlist.js

_kiwi.model.MemberList = Backbone.Collection.extend({
    model: _kiwi.model.Member,
    comparator: function (a, b) {
        var i, a_modes, b_modes, a_idx, b_idx, a_nick, b_nick;
        var user_prefixes = this.channel.get('network').get('user_prefixes');

        a_modes = a.get("modes");
        b_modes = b.get("modes");

        // Try to sort by modes first
        if (a_modes.length > 0) {
            // a has modes, but b doesn't so a should appear first
            if (b_modes.length === 0) {
                return -1;
            }
            a_idx = b_idx = -1;
            // Compare the first (highest) mode
            for (i = 0; i < user_prefixes.length; i++) {
                if (user_prefixes[i].mode === a_modes[0]) {
                    a_idx = i;
                }
            }
            for (i = 0; i < user_prefixes.length; i++) {
                if (user_prefixes[i].mode === b_modes[0]) {
                    b_idx = i;
                }
            }
            if (a_idx < b_idx) {
                return -1;
            } else if (a_idx > b_idx) {
                return 1;
            }
            // If we get to here both a and b have the same highest mode so have to resort to lexicographical sorting

        } else if (b_modes.length > 0) {
            // b has modes but a doesn't so b should appear first
            return 1;
        }
        a_nick = a.get("nick").toLocaleLowerCase();
        b_nick = b.get("nick").toLocaleLowerCase();
        // Lexicographical sorting
        if (a_nick < b_nick) {
            return -1;
        } else if (a_nick > b_nick) {
            return 1;
        } else {
            return 0;
        }
    },


    initialize: function (options) {
        this.view = new _kiwi.view.MemberList({"model": this});
        this.initNickCache();
    },


    /*
     * Keep a reference to each member by the nick. Speeds up .getByNick()
     * so it doesn't need to loop over every model for each nick lookup
     */
    initNickCache: function() {
        var updateRegex = _.bind(function () {
                // Allows checking for a nick that contains 'the_nick' or '<punctuation>the_nick<punctuation>'
                // .. where <punctuation> is any character not allowed in an IRC nick
                var regex_valid_nick_chars = 'a-z0-9_\\-{}[\\]^`|\\\\';
                var regex_nicks = Object.keys(this.nick_cache)
                    .map(_.escapeRegExp)
                    .join('|');

                this.nick_regex = new RegExp(
                    '^[^'+regex_valid_nick_chars+']?(' + regex_nicks + ')[^'+regex_valid_nick_chars+']?$', 'i'
                );
            }, this);

        function getNick (member) {
            return member.get('nick').toLowerCase();
        };

        this.nick_cache = Object.create(null);
        this.nick_regex = null;

        this.on('reset', function() {
            this.nick_cache = _.reduce(this.models, function(memo, member) {
                memo[getNick(member)] = member;
                return memo;
            }, Object.create(null));
            updateRegex();
        });

        this.on('add', function(member) {
            this.nick_cache[getNick(member)] = member;
            updateRegex();
        });

        this.on('remove', function(member) {
            delete this.nick_cache[getNick(member)];
            updateRegex();
        });

        this.on('change:nick', function(member) {
            this.nick_cache[getNick(member)] = member;
            delete this.nick_cache[member.previous('nick').toLowerCase()];
            updateRegex();
        });
    },

    getByNick: function (nick) {
        var matches;
        if (this.nick_regex && (matches = this.nick_regex.exec(nick))) {
            return this.nick_cache[matches[1].toLowerCase()];
        }
    }
});