/* Copyright (c) 2006-2008 MetaCarta, Inc., published under the Clear BSD
 * license.  See http://svn.openlayers.org/trunk/openlayers/license.txt for the
 * full text of the license. */

/**
 * @requires OpenLayers/Format/XML.js
 */

/**
 * Class: OpenLayers.Format.WMCC
 * Read and write Web Map Context documents.
 *
 * Inherits from:
 *  - <OpenLayers.Format.XML>
 */
OpenLayers.Format.WMCC = OpenLayers.Class({
    
    /**
     * APIProperty: defaultVersion
     * {String} Version number to assume if none found.  Default is "1.0.0".
     */
    defaultVersion: "1.0.0",
    
    /**
     * APIProperty: version
     * {String} Specify a version string if one is known.
     */
    version: null,
    
    /**
     * Property: parser
     * {Object} Instance of the versioned parser.  Cached for multiple read and
     *     write calls of the same version.
     */
    parser: null,

    /**
     * Constructor: OpenLayers.Format.WMC
     * Create a new parser for WMC docs.
     *
     * Parameters:
     * options - {Object} An optional object whose properties will be set on
     *     this instance.
     */
    initialize: function(options) {
        OpenLayers.Util.extend(this, options);
        this.options = options;
    },

    /**
     * APIMethod: read
     * Read WMC data from a string, and return an object with map properties
     *     and a list of layers. 
     * 
     * Parameters: 
     * data - {String} or {DOMElement} data to read/parse.
     * options - {Object} The options object must contain a map property.  If
     *     the map property is a string, it must be the id of a dom element
     *     where the new map will be placed.  If the map property is an
     *     <OpenLayers.Map>, the layers from the context document will be added
     *     to the map.
     *
     * Returns:
     * {<OpenLayers.Map>} A map based on the context.
     */
    read: function(data, options) {
        if(typeof data == "string") {
            data = OpenLayers.Format.XML.prototype.read.apply(this, [data]);
        }
        var root = data.documentElement;
        var version = this.version;
        if(!version) {
            version = root.getAttribute("version");
            if(!version) {
                version = this.defaultVersion;
            }
        }
        if(!this.parser || this.parser.VERSION != version) {
            var format = OpenLayers.Format.WMCC[
                "v" + version.replace(/\./g, "_")
            ];
            if(!format) {
                throw "Can't find a WMCC parser for version " +
                      version;
            }
            this.parser = new format(this.options);
        }
        var context = this.parser.read(data, options);
        
        return context;
	},

	CLASS_NAME: "OpenLayers.Format.WMCC" 
});