/**
 * @class Ext.data.DataReader
 * Abstract base class for reading structured data from a data source and converting
 * it into an object containing {@link Ext.data.Record} objects and metadata for use
 * by an {@link Ext.data.Store}.  This class is intended to be extended and should not
 * be created directly. For existing implementations, see {@link Ext.data.ArrayReader},
 * {@link Ext.data.JsonReader} and {@link Ext.data.XmlReader}.
 * @constructor Create a new DataReader
 * @param {Object} meta Metadata configuration options (implementation-specific).
 * @param {Array/Object} recordType
 *

Either an Array of {@link Ext.data.Field Field} definition objects (which
 * will be passed to {@link Ext.data.Record#create}, or a {@link Ext.data.Record Record}
 * constructor created using {@link Ext.data.Record#create}.


 */

Ext.data.DataReader = function(meta, recordType){
   
/**
     * This DataReader's configured metadata as passed to the constructor.
     * @type Mixed
     * @property meta
     */

   
this.meta = meta;
   
/**
     * @cfg {Array/Object} fields
     *

Either an Array of {@link Ext.data.Field Field} definition objects (which
     * will be passed to {@link Ext.data.Record#create}, or a {@link Ext.data.Record Record}
     * constructor created from {@link Ext.data.Record#create}.


     */

   
this.recordType = Ext.isArray(recordType) ?
       
Ext.data.Record.create(recordType) : recordType;

   
// make sure extraction functions are defined.
   
this.buildExtractors();
};

Ext.data.DataReader.prototype = {

   
/**
     * Abstract method, overridden in {@link Ext.data.JsonReader}
     */

    buildExtractors
: Ext.emptyFn,

   
/**
     * Used for un-phantoming a record after a successful database insert.  Sets the records pk along with new data from server.
     * You
must return at least the database pk using the idProperty defined in your DataReader configuration.  The incoming
     * data from server will be merged with the data in the local record.
     * In addition, you
must return record-data from the server in the same order received.
     * Will perform a commit as well, un-marking dirty-fields.  Store's "update" event will be suppressed.
     * @param {Record/Record[]} record The phantom record to be realized.
     * @param {Object/Object[]} data The new record data to apply.  Must include the primary-key from database defined in idProperty field.
     */

    realize
: function(rs, data){
       
if (Ext.isArray(rs)) {
           
for (var i = rs.length - 1; i >= 0; i--) {
               
// recurse
               
if (Ext.isArray(data)) {
                   
this.realize(rs.splice(i,1).shift(), data.splice(i,1).shift());
               
}
               
else {
                   
// weird...rs is an array but data isn't??  recurse but just send in the whole invalid data object.
                   
// the else clause below will detect !this.isData and throw exception.
                   
this.realize(rs.splice(i,1).shift(), data);
               
}
           
}
       
}
       
else {
           
// If rs is NOT an array but data IS, see if data contains just 1 record.  If so extract it and carry on.
           
if (Ext.isArray(data) && data.length == 1) {
                data
= data.shift();
           
}
           
if (!this.isData(data)) {
               
// TODO: Let exception-handler choose to commit or not rather than blindly rs.commit() here.
               
//rs.commit();
               
throw new Ext.data.DataReader.Error('realize', rs);
           
}
           
var values = this.extractValues(data, rs.fields.items, rs.fields.items.length);
            rs
.phantom = false; // <-- That's what it's all about
            rs
._phid = rs.id;  // <-- copy phantom-id -> _phid, so we can remap in Store#onCreateRecords
            rs
.id = data[this.meta.idProperty];
            rs
.data = values;
            rs
.commit();
       
}
   
},

   
/**
     * Used for updating a non-phantom or "real" record's data with fresh data from server after remote-save.
     * If returning data from multiple-records after a batch-update, you
must return record-data from the server in
     * the same order received.  Will perform a commit as well, un-marking dirty-fields.  Store's "update" event will be
     * suppressed as the record receives fresh new data-hash
     * @param {Record/Record[]} rs
     * @param {Object/Object[]} data
     */

    update
: function(rs, data) {
       
if (Ext.isArray(rs)) {
           
for (var i=rs.length-1; i >= 0; i--) {
               
if (Ext.isArray(data)) {
                   
this.update(rs.splice(i,1).shift(), data.splice(i,1).shift());
               
}
               
else {
                   
// weird...rs is an array but data isn't??  recurse but just send in the whole data object.
                   
// the else clause below will detect !this.isData and throw exception.
                   
this.update(rs.splice(i,1).shift(), data);
               
}
           
}
       
}
       
else {
           
// If rs is NOT an array but data IS, see if data contains just 1 record.  If so extract it and carry on.
           
if (Ext.isArray(data) && data.length == 1) {
                data
= data.shift();
           
}
           
if (this.isData(data)) {
                rs
.data = this.extractValues(Ext.apply(rs.data, data), rs.fields.items, rs.fields.items.length);
           
}
            rs
.commit();
       
}
   
},

   
/**
     * Returns true if the supplied data-hash
looks and quacks like data.  Checks to see if it has a key
     * corresponding to idProperty defined in your DataReader config containing non-empty pk.
     * @param {Object} data
     * @return {Boolean}
     */

    isData
: function(data) {
       
return (data && Ext.isObject(data) && !Ext.isEmpty(data[this.meta.idProperty])) ? true : false;
   
}
};

/**
 * @class Ext.data.DataReader.Error
 * @extends Ext.Error
 * General error class for Ext.data.DataReader
 */

Ext.data.DataReader.Error = Ext.extend(Ext.Error, {
   
constructor : function(message, arg) {
       
this.arg = arg;
       
Ext.Error.call(this, message);
   
},
    name
: 'Ext.data.DataReader'
});
Ext.apply(Ext.data.DataReader.Error.prototype, {
    lang
: {
       
'update': "#update received invalid data from server.  Please see docs for DataReader#update and review your DataReader configuration.",
       
'realize': "#realize was called with invalid remote-data.  Please see the docs for DataReader#realize and review your DataReader configuration.",
       
'invalid-response': "#readResponse received an invalid response from the server."
   
}
});