ClassTransform

package br.com.winmidia
{
    import flash.utils.*;

    public class ClassTransform
    {
        /**
         * Transform a JSON data to this ValueObject representation
         * Important: The VO Class must be setted in the application
         *
         * @param json:String   The JSON to be converted
         * @param type:String   The name of the field that have the ClassName of the VO
         * @param data:String   The name of the field that have the Data of the VO
         * @author Wemerson C. Guimarães <[email protected]>
         * @version 0.0.1
         *
         * IF not 'type' or 'data' present, all JSON will be used as the object data...
         * Only when 'type' is not informed, the valueObject must be present
         *
         * Data examples:
         *
         * -----------------------------------------------
         *    // DEFAULT USAGE
         * -----------------------------------------------
         * ClassTransform.json2vo(json)
         * {
         *      "type": "UserVO",
         *      "data": {
         *          "id": 999,
         *          "name": "Wemerson Guimaraes",
         *          "e-mail": "[email protected]
         *      }
         * }
         *
         * -----------------------------------------------
         *    // USE WHEN THE JSON IS JUST THE VO
         * -----------------------------------------------
         * ClassTransform.json2vo(json, UserVO)
         * {
         *      "id": 999,
         *      "name": "Wemerson Guimaraes",
         *      "e-mail": "[email protected]
         * }
         *
         * -----------------------------------------------
         *    // USED WITH TYPE/DATA CUSTOMIZED
         * -----------------------------------------------
         * ClassTransform.json2vo(json, null, 'tipo', 'dados' ) // without VO and type and data customized
         * {
         *      "tipo": "UserVO",
         *      "dados": {
         *          "id": 999,
         *          "name": "Wemerson Guimaraes",
         *          "e-mail": "[email protected]
         *      }
         * }
         *
         */
        public static function json2vo(json:String, valueObject:Class = null, type:String = 'type', data:String = 'data' ):*{

            // Object complete, with all fields, including 'type' and 'data'
            // (if they exists will be parsed later in this function)
            try{
                var oFullConverted:Object = JSON.parse( json );
            }catch(e:Error){
                throw new Error("Falha tentar fazer o parse do JSON");
            }

            // get the 'type' of object, must have more manipulation after dataRoot
            var iType:String = oFullConverted[type];

            // get tye 'data' from the object
            var dataRoot:Object;
            try{
                if(oFullConverted[data] == null || iType == null)
                    dataRoot = oFullConverted;// type and data invalid, get all data
                else
                    dataRoot = oFullConverted[data]; // get data
            }catch(e:Error){
                throw new Error("JSON inválido!!!");
            }


            if(iType == null && valueObject == null)
                throw new Error("Tipagem do VO não definida no JSON, necessário informar ValueObject corretamente");
            else if(valueObject != null)
                iType = getQualifiedClassName(valueObject);

            // Instantiate the VO class
            try{
                var clazz:Class = Class( getDefinitionByName(iType) );
                var vo:Object = new clazz();
            }catch(e:Error){
                throw new Error("Tentativa de mapear uma classe inválida!");
            }

            var classInfo:XML = describeType(vo);

            // List accessors as properties. To convert to VO's only the part of properties is needed
            // For now only VOs with simple fields is supported
            // Feel free to implement complex fields like arrays and collections of data as a VO field
            for each (var accessor:XML in classInfo..accessor) {
                if (accessor.@access != 'writeonly')
                    vo[accessor.@name] = dataRoot[accessor.@name];
            }

            return vo;
        }
    }
}