/*
This file is part of Ext JS 3.4

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as
published by the Free Software Foundation and appearing in the file LICENSE included in the
packaging of this file.

Please review the following information to ensure the GNU General Public License version 3.0
requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-04-03 15:07:25
*/
/**
 * @class Ext.data.Field
 * <p>This class encapsulates the field definition information specified in the field definition objects
 * passed to {@link Ext.data.Record#create}.</p>
 * <p>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 <b>prototype.</b></p>
 */
Ext.data.Field = Ext.extend(Object, {
    
    constructor : function(config){
        if(Ext.isString(config)){
            config = {name: config};
        }
        Ext.apply(this, config);
        
        var types = Ext.data.Types,
            st = this.sortType,
            t;

        if(this.type){
            if(Ext.isString(this.type)){
                this.type = Ext.data.Types[this.type.toUpperCase()] || types.AUTO;
            }
        }else{
            this.type = types.AUTO;
        }

        // named sortTypes are supported, here we look them up
        if(Ext.isString(st)){
            this.sortType = Ext.data.SortTypes[st];
        }else if(Ext.isEmpty(st)){
            this.sortType = this.type.sortType;
        }

        if(!this.convert){
            this.convert = this.type.convert;
        }
    },
    
    /**
     * @cfg {String} name
     * The name by which the field is referenced within the Record. This is referenced by, for example,
     * the <code>dataIndex</code> property in column definition objects passed to {@link Ext.grid.ColumnModel}.
     * <p>Note: In the simplest case, if no properties other than <code>name</code> are required, a field
     * definition may consist of just a String for the field name.</p>
     */
    /**
     * @cfg {Mixed} type
     * (Optional) The data type for automatic conversion from received data to the <i>stored</i> value if <code>{@link Ext.data.Field#convert convert}</code>
     * has not been specified. This may be specified as a string value. Possible values are
     * <div class="mdetail-params"><ul>
     * <li>auto (Default, implies no conversion)</li>
     * <li>string</li>
     * <li>int</li>
     * <li>float</li>
     * <li>boolean</li>
     * <li>date</li></ul></div>
     * <p>This may also be specified by referencing a member of the {@link Ext.data.Types} class.</p>
     * <p>Developers may create their own application-specific data types by defining new members of the
     * {@link Ext.data.Types} class.</p>
     */
    /**
     * @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:<div class="mdetail-params"><ul>
     * <li><b>v</b> : Mixed<div class="sub-desc">The data value as read by the Reader, if undefined will use
     * the configured <code>{@link Ext.data.Field#defaultValue defaultValue}</code>.</div></li>
     * <li><b>rec</b> : Mixed<div class="sub-desc">The data object containing the row as read by the Reader.
     * Depending on the Reader type, this could be an Array ({@link Ext.data.ArrayReader ArrayReader}), an object
     *  ({@link Ext.data.JsonReader JsonReader}), or an XML element ({@link Ext.data.XMLReader XMLReader}).</div></li>
     * </ul></div>
     * <pre><code>
// 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'
    }
];
     * </code></pre>
     */
    /**
     * @cfg {String} dateFormat
     * <p>(Optional) Used when converting received data into a Date when the {@link #type} is specified as <code>"date"</code>.</p>
     * <p>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. See {@link Date}</p>
     */
    dateFormat: null,
    
    /**
     * @cfg {Boolean} useNull
     * <p>(Optional) Use when converting received data into a Number type (either int or float). If the value cannot be parsed,
     * null will be used if useNull is true, otherwise the value will be 0. Defaults to <tt>false</tt>
     */
    useNull: false,
    
    /**
     * @cfg {Mixed} defaultValue
     * (Optional) The default value used <b>when a Record is being created by a {@link Ext.data.Reader Reader}</b>
     * when the item referenced by the <code>{@link Ext.data.Field#mapping mapping}</code> does not exist in the data
     * object (i.e. undefined). (defaults to "")
     */
    defaultValue: "",
    /**
     * @cfg {String/Number} mapping
     * <p>(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.</p>
     * <p>The form of the mapping expression depends on the Reader being used.</p>
     * <div class="mdetail-params"><ul>
     * <li>{@link Ext.data.JsonReader}<div class="sub-desc">The mapping is a string containing the javascript
     * expression to reference the data from an element of the data item's {@link Ext.data.JsonReader#root root} Array. Defaults to the field name.</div></li>
     * <li>{@link Ext.data.XmlReader}<div class="sub-desc">The mapping is an {@link Ext.DomQuery} path to the data
     * item relative to the DOM element that represents the {@link Ext.data.XmlReader#record record}. Defaults to the field name.</div></li>
     * <li>{@link Ext.data.ArrayReader}<div class="sub-desc">The mapping is a number indicating the Array index
     * of the field's value. Defaults to the field specification's Array position.</div></li>
     * </ul></div>
     * <p>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.</p>
     */
    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:<pre><code>
// 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;
   }
}
     * </code></pre>
     */
    sortType : null,
    /**
     * @cfg {String} sortDir
     * (Optional) Initial direction to sort (<code>"ASC"</code> or  <code>"DESC"</code>).  Defaults to
     * <code>"ASC"</code>.
     */
    sortDir : "ASC",
    /**
     * @cfg {Boolean} allowBlank
     * (Optional) Used for validating a {@link Ext.data.Record record}, defaults to <code>true</code>.
     * An empty value here will cause {@link Ext.data.Record}.{@link Ext.data.Record#isValid isValid}
     * to evaluate to <code>false</code>.
     */
    allowBlank : true
});
