lace.js

"use strict";

function Lace(selector) {
    var nodes, el;

    // Handle situation where called without "new" keyword
    if (false === (this instanceof Lace)) {
        return new Lace(selector);
    }

    if (typeof selector === "undefined") {
        // No selectors passed, create an empty node
        nodes = null;
    } else if (typeof selector !== "string") {
        if (typeof selector === "object" && selector.nodeType > 0) {
            // A DOM node passed, add it to the nodes array
            nodes = [ selector ];
        } else if (typeof selector === "object" && selector.length) {
            // An HTMLCollection is passed, set it to the nodes
            nodes = selector;
        } else {
            throw new TypeError("Invalid selector: " + selector);
        }
    } else {
        if (/^<[a-z]+>$/.test(selector)) {
            // Create a new DOM node
            el = selector.replace(/((^<)|(>$))/g, "");

            nodes = [ document.createElement(el) ];
        } else {
            if (/^#/.test(selector)) {
                // An ID was passed
                nodes = [ document.getElementById(selector.replace(/^#/, "")) ];
            } else if (/^\./.test(selector)) {
                // A class name was passed
                nodes = document.getElementsByClassName(selector.replace(/^\./, ""));
            } else if (/^[a-z]+$/.test(selector)) {
                // A tagname was passed
                nodes = document.getElementsByTagName(selector);
            } else {
                nodes = document.querySelectorAll(selector);
            }
        }
    }

    // Add elements
    for (var i = nodes.length - 1; i >= 0; i--) {
        if (nodes[i] && nodes[i].nodeType > 0) {
            this[i] = nodes[i];
        }
    }

    // Add the length property
    Object.defineProperty(this, "length", {
        get: function() {
            return nodes.length;
        }
    });

    // An HTMLCollection is immutable
    Object.freeze(this);
}

// Add all array methods
Lace.prototype = Object.create(Array.prototype);

// Helper methods
Lace.prototype.item = function(index) {
    if (typeof index !== "number") {
        throw new TypeError("Invalid index: " + index);
    }

    return this.length > index ? this[index] : null;
};

Lace.prototype.each = function(callback) {
    if (typeof callback !== "function") {
        throw new TypeError("Invalid callback: " + callback);
    }

    for (var i = this.length - 1; i >= 0; i--) {
        callback.call(this.item(i), i);
    }

    return this;
};

// Add a method to get the first item from a collection
Lace._ = function(selector) {
    if (selector instanceof Lace) {
        return selector.item(0);
    } else if (selector.nodeType > 0) {
        return selector;
    } else {
        return (new Lace(selector)).item(0);
    }
};

// Let's add a DOM ready listener
Lace.ready = function(callback) {
    if (typeof callback !== "function") {
        throw new TypeError("Invalid listener: " + callback);
    }

    if (document.readyState === "complete") {
        // document is already ready
        callback();
    } else {
        // document is not ready, wait till it's ready
        document.addEventListener("readystatechange", function() {
            if (document.readyState === "complete") {
                callback();
            }
        }, false);
    }
};

// We need a object extend functionality
Lace.extend = function() {
    var objs = Array.prototype.slice.call(arguments, 0),
        orig = objs[0];

    if (typeof orig !== "object" || orig === null) {
        return orig;
    }

    for (var i = 1, l = objs.length; i < l; i++) {
        if (typeof objs[i] !== "object" || objs[i] === null) {
            return orig;
        }

        for (var o in objs[i]) {
            if (objs[i].hasOwnProperty(o)) {
                if (typeof orig[o] === "object") {
                    this.extend(orig[o], objs[i][o]);
                } else {
                    orig[o] = objs[i][o];
                }
            }
        }
    }

    return orig;
};

// Add a plugin system
Lace.plugin = function(name, defaults, methods) {
    var extend = this.extend;

    this.prototype[name] = function(method, options) {
        if (typeof method === "object") {
            options = method;
            method = "init";
        }

        if (typeof method === "undefined") {
            method = "init";
        }

        if (typeof method === "string" && typeof methods[method] === "function") {
            methods[method].call(this, extend({}, defaults, options));
        }
    };
};

// Export modules
if (typeof define === "function" && define.amd) {
    // Define as AMD module
    define(function() {
        return Lace;
    });
} else if (typeof module !== "undefined" && module.exports) {
    // Export to CommonJS
    module.exports = Lace;
} else {
    // Export to global object
    window.Lace = Lace;
}