/**
 * @class Ext.data.Field
 *

This class encapsulates the field definition information specified in the field definition objects
 * passed to {@link Ext.data.Record#create}.


 *

Developers do not need to instantiate this class. Instances are created by {@link Ext.data.Record.create}
 * and cached in the {@link Ext.data.Record#fields fields} property of the created Record constructor's
prototype.


 */

Ext.data.Field = function(config){
   
if(typeof config == "string"){
        config
= {name: config};
   
}
   
Ext.apply(this, config);

   
if(!this.type){
       
this.type = "auto";
   
}

   
var st = Ext.data.SortTypes;
   
// named sortTypes are supported, here we look them up
   
if(typeof this.sortType == "string"){
       
this.sortType = st[this.sortType];
   
}

   
// set default sortType for strings and dates
   
if(!this.sortType){
       
switch(this.type){
           
case "string":
               
this.sortType = st.asUCString;
               
break;
           
case "date":
               
this.sortType = st.asDate;
               
break;
           
default:
               
this.sortType = st.none;
       
}
   
}

   
// define once
   
var stripRe = /[\$,%]/g;

   
// prebuilt conversion function for this field, instead of
   
// switching every time we're reading a value
   
if(!this.convert){
       
var cv, dateFormat = this.dateFormat;
       
switch(this.type){
           
case "":
           
case "auto":
           
case undefined:
                cv
= function(v){ return v; };
               
break;
           
case "string":
                cv
= function(v){ return (v === undefined || v === null) ? '' : String(v); };
               
break;
           
case "int":
                cv
= function(v){
                   
return v !== undefined && v !== null && v !== '' ?
                           parseInt
(String(v).replace(stripRe, ""), 10) : '';
                   
};
               
break;
           
case "float":
                cv
= function(v){
                   
return v !== undefined && v !== null && v !== '' ?
                           parseFloat
(String(v).replace(stripRe, ""), 10) : '';
                   
};
               
break;
           
case "bool":
           
case "boolean":
                cv
= function(v){ return v === true || v === "true" || v == 1; };
               
break;
           
case "date":
                cv
= function(v){
                   
if(!v){
                       
return '';
                   
}
                   
if(Ext.isDate(v)){
                       
return v;
                   
}
                   
if(dateFormat){
                       
if(dateFormat == "timestamp"){
                           
return new Date(v*1000);
                       
}
                       
if(dateFormat == "time"){
                           
return new Date(parseInt(v, 10));
                       
}
                       
return Date.parseDate(v, dateFormat);
                   
}
                   
var parsed = Date.parse(v);
                   
return parsed ? new Date(parsed) : null;
               
};
             
break;

       
}
       
this.convert = cv;
   
}
};

Ext.data.Field.prototype = {
   
/**
     * @cfg {String} name
     * The name by which the field is referenced within the Record. This is referenced by, for example,
     * the
dataIndex property in column definition objects passed to {@link Ext.grid.ColumnModel}.
     *

Note: In the simplest case, if no properties other than name are required, a field
     * definition may consist of just a String for the field name.


     */

   
/**
     * @cfg {String} type
     * (Optional) The data type for conversion to displayable value if
{@link Ext.data.Field#convert convert}
     * has not been specified. Possible values are
     *

     */

   
/**
     * @cfg {Function} convert
     * (Optional) A function which converts the value provided by the Reader into an object that will be stored
     * in the Record. It is passed the following parameters:

     *

// example of convert function
function fullName(v, record){
    return record.name.last + ', ' + record.name.first;
}

function location(v, record){
    return !record.city ? '' : (record.city + ', ' + record.state);
}

var Dude = Ext.data.Record.create([
    {name: 'fullname',  convert: fullName},
    {name: 'firstname', mapping: 'name.first'},
    {name: 'lastname',  mapping: 'name.last'},
    {name: 'city', defaultValue: 'homeless'},
    'state',
    {name: 'location',  convert: location}
]);

// create the data store
var store = new Ext.data.Store({
    reader: new Ext.data.JsonReader(
        {
            idProperty: 'key',
            root: 'daRoot',  
            totalProperty: 'total'
        },
        Dude  // recordType
    )
});

var myData = [
    { key: 1,
      name: { first: 'Fat',    last:  'Albert' }
      // notice no city, state provided in data object
    },
    { key: 2,
      name: { first: 'Barney', last:  'Rubble' },
      city: 'Bedrock', state: 'Stoneridge'
    },
    { key: 3,
      name: { first: 'Cliff',  last:  'Claven' },
      city: 'Boston',  state: 'MA'
    }
];
     *

     */

   
/**
     * @cfg {String} dateFormat
     * (Optional) A format string for the {@link Date#parseDate Date.parseDate} function, or "timestamp" if the
     * value provided by the Reader is a UNIX timestamp, or "time" if the value provided by the Reader is a
     * javascript millisecond timestamp.
     */

    dateFormat
: null,
   
/**
     * @cfg {Mixed} defaultValue
     * (Optional) The default value used
when a Record is being created by a {@link Ext.data.Reader Reader}
     * when the item referenced by the
{@link Ext.data.Field#mapping mapping} does not exist in the data
     * object (i.e. undefined). (defaults to "")
     */

    defaultValue
: "",
   
/**
     * @cfg {String/Number} mapping
     *

(Optional) A path expression for use by the {@link Ext.data.DataReader} implementation
     * that is creating the {@link Ext.data.Record Record} to extract the Field value from the data object.
     * If the path expression is the same as the field name, the mapping may be omitted.


     *

The form of the mapping expression depends on the Reader being used.


     *

     *

If a more complex value extraction strategy is required, then configure the Field with a {@link #convert}
     * function. This is passed the whole row object, and may interrogate it in whatever way is necessary in order to
     * return the desired data.


     */

    mapping
: null,
   
/**
     * @cfg {Function} sortType
     * (Optional) A function which converts a Field's value to a comparable value in order to ensure
     * correct sort ordering. Predefined functions are provided in {@link Ext.data.SortTypes}. A custom
     * sort example:

// current sort     after sort we want
// +-+------+          +-+------+
// |1|First |          |1|First |
// |2|Last  |          |3|Second|
// |3|Second|          |2|Last  |
// +-+------+          +-+------+

sortType: function(value) {
   switch (value.toLowerCase()) // native toLowerCase():
   {
      case 'first': return 1;
      case 'second': return 2;
      default: return 3;
   }
}
     *

     */

    sortType
: null,
   
/**
     * @cfg {String} sortDir
     * (Optional) Initial direction to sort (
"ASC" or  "DESC").  Defaults to
     *
"ASC".
     */

    sortDir
: "ASC",
       
/**
         * @cfg {Boolean} allowBlank
         * (Optional) Used for validating a {@link Ext.data.Record record}, defaults to
true.
         * An empty value here will cause {@link Ext.data.Record}.{@link Ext.data.Record#isValid isValid}
         * to evaluate to
false.
         */

        allowBlank
: true
};