// Copyright (c) 2005 Thomas Fuchs (http://script.aculo.us, http://mir.aculo.us)
//
// See scriptaculous.js for full license.

var Builder = {
    NODEMAP:{
        AREA:'map',
        CAPTION:'table',
        COL:'table',
        COLGROUP:'table',
        LEGEND:'fieldset',
        OPTGROUP:'select',
        OPTION:'select',
        PARAM:'object',
        TBODY:'table',
        TD:'table',
        TFOOT:'table',
        TH:'table',
        THEAD:'table',
        TR:'table'
    },
    // note: For Firefox < 1.5, OPTION and OPTGROUP tags are currently broken,
    //       due to a Firefox bug
    node:function (elementName) {
        elementName = elementName.toUpperCase();

        // try innerHTML approach
        var parentTag = this.NODEMAP[elementName] || 'div';
        var parentElement = document.createElement(parentTag);
        try { // prevent IE "feature": http://dev.rubyonrails.org/ticket/2707
            parentElement.innerHTML = "<" + elementName + "></" + elementName + ">";
        } catch (e) {
        }
        var element = parentElement.firstChild || null;

        // see if browser added wrapping tags
        if (element && (element.tagName != elementName))
            element = element.getElementsByTagName(elementName)[0];

        // fallback to createElement approach
        if (!element) element = document.createElement(elementName);

        // abort if nothing could be created
        if (!element) return;

        // attributes (or text)
        if (arguments[1])
            if (this._isStringOrNumber(arguments[1]) ||
                (arguments[1] instanceof Array)) {
                this._children(element, arguments[1]);
            } else {
                var attrs = this._attributes(arguments[1]);
                if (attrs.length) {
                    try { // prevent IE "feature": http://dev.rubyonrails.org/ticket/2707
                        parentElement.innerHTML = "<" + elementName + " " +
                            attrs + "></" + elementName + ">";
                    } catch (e) {
                    }
                    element = parentElement.firstChild || null;
                    // workaround firefox 1.0.X bug
                    if (!element) {
                        element = document.createElement(elementName);
                        for (attr in arguments[1])
                            element[attr == 'class' ? 'className' : attr] = arguments[1][attr];
                    }
                    if (element.tagName != elementName)
                        element = parentElement.getElementsByTagName(elementName)[0];
                }
            }

        // text, or array of children
        if (arguments[2])
            this._children(element, arguments[2]);

        return element;
    },
    _text:function (text) {
        return document.createTextNode(text);
    },
    _attributes:function (attributes) {
        var attrs = [];
        for (attribute in attributes)
            attrs.push((attribute == 'className' ? 'class' : attribute) +
                '="' + attributes[attribute].toString().escapeHTML() + '"');
        return attrs.join(" ");
    },
    _children:function (element, children) {
        if (typeof children == 'object') { // array can hold nodes and text
            children.flatten().each(function (e) {
                if (typeof e == 'object')
                    element.appendChild(e)
                else
                if (Builder._isStringOrNumber(e))
                    element.appendChild(Builder._text(e));
            });
        } else
        if (Builder._isStringOrNumber(children))
            element.appendChild(Builder._text(children));
    },
    _isStringOrNumber:function (param) {
        return(typeof param == 'string' || typeof param == 'number');
    }
}