searchable and sortable data structure - Using NodeJS

searchable and sortable data structure - Plugin NodeJS

//sortable-2d-array.js
exports = module.exports = sortable2DArray;

function sortable2DArray(data) {
    this.data = data;
}


sortable2DArray.prototype.sortBy = function (o) {
    var fields = o.fields || [];
    var dir = o.dir || [];
    var dataCopy = this.data.slice(0);
    if (!fields.length) {
        return dataCopy;
    }
    var sortOptions = [];
    for (var i = 0, tmp; i < fields.length; i++) {
        if (typeof fields[i] == "undefined") continue;
        var tmp = (typeof dir[i] == "undefined") ? "asc" : dir[i];
        tmp = "" + tmp;
        tmp = tmp.toLowerCase();
        if (tmp == "desc" || tmp == "descending") {
            sortOptions.push(["" + fields[i], "desc"]);
            continue;
        }
        sortOptions.push(["" + fields[i], "asc"]);
    }

    if (!sortOptions.length) {
        return dataCopy;
    }

    //note that sort directly edits the array so we are working on a copy
    dataCopy.sort(function (itemA, itemB) {
        for (var i = 0, a, b, dir, c; i < sortOptions.length; i++) {
            a = itemA[sortOptions[i][0]];
            b = itemB[sortOptions[i][0]];
            dir = sortOptions[i][1];
            if (typeof a == "number") {
                c = (dir == "asc") ? a - b : b - a;
                if (c > 0) return 1;
                if (c < 0) return -1;
                continue;
            } else if (typeof a == "string") {
                if (dir == "asc") {
                    if (a > b) return 1;
                    if (b > a) return -1;
                    continue;
                } else {
                    if (b > a) return 1;
                    if (a > b) return -1;
                    continue;
                }
            } else {
                continue;
            }
        }
        return 0;
    });
    return dataCopy;
}


//var data=d.sortBy({fields:["name","age"],dir:["asc","desc"]});

var data = new Array(5);
data[0] = {
    name: "Nandan Argulkar",
    age: 28,
    gender: "male"
};
data[1] = {
    name: "Mani",
    age: 25,
    gender: "male"
};
data[2] = {
    name: "Priya",
    age: 31,
    gender: "female"
};
data[3] = {
    name: "Nandini",
    age: 19,
    gender: "female"
};
data[4] = {
    name: "Kevin",
    age: 20,
    gender: "male"
};
alert(data.toSource());
var d = new sortable2DArray(data);
var result = d.sortBy({
    fields: ["name", "age"],
    dir: ["asc", "desc"]
});
alert(result.toSource());