Ext JS 4.1.3 Sencha Docs

Ext.data.Field

Hierarchy

Ext.Base
Ext.data.Field

Requires

Files

Fields are used to define what a Model is. They aren't instantiated directly - instead, when we create a class that extends Ext.data.Model, it will automatically create a Field instance for each field configured in a Model. For example, we might set up a model like this:

Ext.define('User', {
    extend: 'Ext.data.Model',
    fields: [
        'name', 'email',
        {name: 'age', type: 'int'},
        {name: 'gender', type: 'string', defaultValue: 'Unknown'}
    ]
});

Four fields will have been created for the User Model - name, email, age and gender. Note that we specified a couple of different formats here; if we only pass in the string name of the field (as with name and email), the field is set up with the 'auto' type. It's as if we'd done this instead:

Ext.define('User', {
    extend: 'Ext.data.Model',
    fields: [
        {name: 'name', type: 'auto'},
        {name: 'email', type: 'auto'},
        {name: 'age', type: 'int'},
        {name: 'gender', type: 'string', defaultValue: 'Unknown'}
    ]
});

Types and conversion

The type is important - it's used to automatically convert data passed to the field into the correct format. In our example above, the name and email fields used the 'auto' type and will just accept anything that is passed into them. The 'age' field had an 'int' type however, so if we passed 25.4 this would be rounded to 25.

Sometimes a simple type isn't enough, or we want to perform some processing when we load a Field's data. We can do this using a convert function. Here, we're going to create a new field based on another:

Ext.define('User', {
    extend: 'Ext.data.Model',
    fields: [
        {
            name: 'firstName',
            convert: function(value, record) {
                var fullName  = record.get('name'),
                    splits    = fullName.split(" "),
                    firstName = splits[0];

                return firstName;
            }
        },
        'name', 'email',
        {name: 'age', type: 'int'},
        {name: 'gender', type: 'string', defaultValue: 'Unknown'}
    ]
});

Now when we create a new User, the firstName is populated automatically based on the name:

var ed = Ext.create('User', {name: 'Ed Spencer'});

console.log(ed.get('firstName')); //logs 'Ed', based on our convert function

Fields which are configured with a custom convert function are read after all other fields when constructing and reading records, so that if convert functions rely on other, non-converted fields (as in this example), they can be sure of those fields being present.

In fact, if we log out all of the data inside ed, we'll see this:

console.log(ed.data);

//outputs this:
{
    age: 0,
    email: "",
    firstName: "Ed",
    gender: "Unknown",
    name: "Ed Spencer"
}

The age field has been given a default of zero because we made it an int type. As an auto field, email has defaulted to an empty string. When we registered the User model we set gender's defaultValue to 'Unknown' so we see that now. Let's correct that and satisfy ourselves that the types work as we expect:

ed.set('gender', 'Male');
ed.get('gender'); //returns 'Male'

ed.set('age', 25.4);
ed.get('age'); //returns 25 - we wanted an int, not a float, so no decimal places allowed

Available since: 2.3.0

Defined By

Config options

Ext.data.Field
view source
: Booleanprivate
Used for validating a model. ...

Used for validating a model. Defaults to true. An empty value here will cause Ext.data.Model.isValid to evaluate to false.

Defaults to: true

Available since: 3.4.0

A function which converts the value provided by the Reader into an object that will be stored in the Model. ...

A function which converts the value provided by the Reader into an object that will be stored in the Model.

If configured as null, then no conversion will be applied to the raw data property when this Field is read. This will increase performance. but you must ensure that the data is of the correct type and does not need converting.

It is passed the following parameters:

  • v : Mixed

    The data value as read by the Reader, if undefined will use the configured defaultValue.

  • rec : Ext.data.Model

    The data object containing the Model as read so far by the Reader. Note that the Model may not be fully populated at this point as the fields are read in the order that they are defined in your fields array.

Example of convert functions:

function fullName(v, record){
    return record.data.last + ', ' + record.data.first;
}

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

Ext.define('Dude', {
    extend: 'Ext.data.Model',
    fields: [
        {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 = Ext.create('Ext.data.Store', {
    reader: {
        type: 'json',
        model: 'Dude',
        idProperty: 'key',
        root: 'daRoot',
        totalProperty: 'total'
    }
});

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'
    }
];

Available since: 2.3.0

Serves as a default for the dateReadFormat and dateWriteFormat config options. ...

Serves as a default for the dateReadFormat and dateWriteFormat config options. This will be used in place of those other configurations if not specified.

A format string for the Ext.Date.parse 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 Ext.Date.

It is quite important to note that while this config is optional, it will default to using the base JavaScript Date object's parse function if not specified, rather than Ext.Date.parse. This can cause unexpected issues, especially when converting between timezones, or when converting dates that do not have a timezone specified. The behavior of the native Date.parse is implementation-specific, and depending on the value of the date string, it might return the UTC date or the local date. For this reason it is strongly recommended that you always specify an explicit date format when parsing dates.

Available since: 2.3.0

Used when converting received data into a Date when the type is specified as "date". ...

Used when converting received data into a Date when the type is specified as "date". This configuration takes precedence over dateFormat. See dateFormat for more information.

Available since: Ext JS 4.1.3

Used to provide a custom format when serializing dates with a Ext.data.writer.Writer. ...

Used to provide a custom format when serializing dates with a Ext.data.writer.Writer. If this is not specified, the dateFormat will be used. See the Ext.data.writer.Writer docs for more information on writing dates.

Available since: Ext JS 4.1.3

The default value used when the creating an instance from a raw data object, and the property referenced by the mappi...

The default value used when the creating an instance from a raw data object, and the property referenced by the mapping does not exist in that data object.

May be specified as undefined to prevent defaulting in a value.

Defaults to: ""

Available since: 2.3.0

(Optional) A path expression for use by the Ext.data.reader.Reader implementation that is creating the Model to extra...

(Optional) A path expression for use by the Ext.data.reader.Reader implementation that is creating the Model 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.

  • Ext.data.reader.Json

    The mapping is a string containing the javascript expression to reference the data from an element of the data item's root Array. Defaults to the field name.

  • Ext.data.reader.Xml

    The mapping is an Ext.DomQuery path to the data item relative to the DOM element that represents the record. Defaults to the field name.

  • Ext.data.reader.Array

    The mapping is a number indicating the Array index of the field's value. Defaults to the field specification's Array position.

If a more complex value extraction strategy is required, then configure the Field with a 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.

Available since: 2.3.0

Ext.data.Field
view source
: String
The name by which the field is referenced within the Model. ...

The name by which the field is referenced within the Model. This is referenced by, for example, the dataIndex property in column definition objects passed to Ext.grid.property.HeaderContainer.

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.

Available since: 2.3.0

Ext.data.Field
view source
: Boolean
False to exclude this field from the Ext.data.Model.modified fields in a model. ...

False to exclude this field from the Ext.data.Model.modified fields in a model. This will also exclude the field from being written using a Ext.data.writer.Writer. This option is useful when model fields are used to keep state on the client but do not need to be persisted to the server. Defaults to true.

Defaults to: true

Available since: 4.0.0

A function which converts the Model's value for this Field into a form which can be used by whatever Writer is being ...

A function which converts the Model's value for this Field into a form which can be used by whatever Writer is being used to sync data with the server.

The function should return a string which represents the Field's value.

It is passed the following parameters:

  • v : Mixed

    The Field's value - the value to be serialized.

  • rec : Ext.data.Model

    The record being serialized.

Available since: 4.1.1

Ext.data.Field
view source
: String
Initial direction to sort ("ASC" or "DESC"). ...

Initial direction to sort ("ASC" or "DESC"). Defaults to "ASC".

Defaults to: "ASC"

Available since: 2.3.0

A function which converts a Field's value to a comparable value in order to ensure correct sort ordering. ...

A function which converts a Field's value to a comparable value in order to ensure correct sort ordering. Predefined functions are provided in 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;
   }
}

May also be set to a String value, corresponding to one of the named sort types in Ext.data.SortTypes.

Available since: 2.3.0

Ext.data.Field
view source
: String/Object
The data type for automatic conversion from received data to the stored value if convert has not been specified. ...

The data type for automatic conversion from received data to the stored value if convert has not been specified. This may be specified as a string value. Possible values are

  • auto (Default, implies no conversion)
  • string
  • int
  • float
  • boolean
  • date

This may also be specified by referencing a member of the Ext.data.Types class.

Developers may create their own application-specific data types by defining new members of the Ext.data.Types class.

Available since: 2.3.0

Ext.data.Field
view source
: Boolean
Use when converting received data into a INT, FLOAT, BOOL or STRING type. ...

Use when converting received data into a INT, FLOAT, BOOL or STRING type. If the value cannot be parsed, null will be used if useNull is true, otherwise a default value for that type will be used:

  • for INT and FLOAT - 0.
  • for STRING - "".
  • for BOOL - false.

Note that when parsing of DATE type fails, the value will be null regardless of this setting.

Defaults to: false

Available since: 3.4.0

Properties

Defined By

Instance properties

...

Defaults to: 'Ext.Base'

Available since: 4.1.1

...

Defaults to: {}

Available since: 4.1.1

...

Defaults to: []

Available since: 4.1.1

...

Defaults to: {}

Available since: 4.1.1

Ext.data.Field
view source
: Booleanprivate
...

Defaults to: true

Available since: 4.1.1

...

Defaults to: true

Available since: 4.1.1

Get the reference to the current class from which this object was instantiated. ...

Get the reference to the current class from which this object was instantiated. Unlike statics, this.self is scope-dependent and it's meant to be used for dynamic inheritance. See statics for a detailed comparison

Ext.define('My.Cat', {
    statics: {
        speciesName: 'Cat' // My.Cat.speciesName = 'Cat'
    },

    constructor: function() {
        alert(this.self.speciesName); // dependent on 'this'
    },

    clone: function() {
        return new this.self();
    }
});


Ext.define('My.SnowLeopard', {
    extend: 'My.Cat',
    statics: {
        speciesName: 'Snow Leopard'         // My.SnowLeopard.speciesName = 'Snow Leopard'
    }
});

var cat = new My.Cat();                     // alerts 'Cat'
var snowLeopard = new My.SnowLeopard();     // alerts 'Snow Leopard'

var clone = snowLeopard.clone();
alert(Ext.getClassName(clone));             // alerts 'My.SnowLeopard'

Available since: 4.0.0

Defined By

Static properties

...

Defaults to: []

Available since: 4.1.1

Methods

Defined By

Instance methods

Ext.data.Field
view source
new( config ) : Ext.data.Field
...

Available since: 3.4.0

Parameters

Returns

( args ) : Objectdeprecatedprotected
Call the original method that was previously overridden with override Ext.define('My.Cat', { constructor: functi...

Call the original method that was previously overridden with override

Ext.define('My.Cat', {
    constructor: function() {
        alert("I'm a cat!");
    }
});

My.Cat.override({
    constructor: function() {
        alert("I'm going to be a cat!");

        this.callOverridden();

        alert("Meeeeoooowwww");
    }
});

var kitty = new My.Cat(); // alerts "I'm going to be a cat!"
                          // alerts "I'm a cat!"
                          // alerts "Meeeeoooowwww"

Available since: 4.0.0

This method has been deprecated

as of 4.1. Use callParent instead.

Parameters

  • args : Array/Arguments

    The arguments, either an array or the arguments object from the current method, for example: this.callOverridden(arguments)

Returns

  • Object

    Returns the result of calling the overridden method

Call the "parent" method of the current method. ...

Call the "parent" method of the current method. That is the method previously overridden by derivation or by an override (see Ext.define).

 Ext.define('My.Base', {
     constructor: function (x) {
         this.x = x;
     },

     statics: {
         method: function (x) {
             return x;
         }
     }
 });

 Ext.define('My.Derived', {
     extend: 'My.Base',

     constructor: function () {
         this.callParent([21]);
     }
 });

 var obj = new My.Derived();

 alert(obj.x);  // alerts 21

This can be used with an override as follows:

 Ext.define('My.DerivedOverride', {
     override: 'My.Derived',

     constructor: function (x) {
         this.callParent([x*2]); // calls original My.Derived constructor
     }
 });

 var obj = new My.Derived();

 alert(obj.x);  // now alerts 42

This also works with static methods.

 Ext.define('My.Derived2', {
     extend: 'My.Base',

     statics: {
         method: function (x) {
             return this.callParent([x*2]); // calls My.Base.method
         }
     }
 });

 alert(My.Base.method(10);     // alerts 10
 alert(My.Derived2.method(10); // alerts 20

Lastly, it also works with overridden static methods.

 Ext.define('My.Derived2Override', {
     override: 'My.Derived2',

     statics: {
         method: function (x) {
             return this.callParent([x*2]); // calls My.Derived2.method
         }
     }
 });

 alert(My.Derived2.method(10); // now alerts 40

To override a method and replace it and also call the superclass method, use callSuper. This is often done to patch a method to fix a bug.

Available since: 4.0.0

Parameters

  • args : Array/Arguments

    The arguments, either an array or the arguments object from the current method, for example: this.callParent(arguments)

Returns

  • Object

    Returns the result of calling the parent method

( args ) : Objectprotected
This method is used by an override to call the superclass method but bypass any overridden method. ...

This method is used by an override to call the superclass method but bypass any overridden method. This is often done to "patch" a method that contains a bug but for whatever reason cannot be fixed directly.

Consider:

 Ext.define('Ext.some.Class', {
     method: function () {
         console.log('Good');
     }
 });

 Ext.define('Ext.some.DerivedClass', {
     method: function () {
         console.log('Bad');

         // ... logic but with a bug ...

         this.callParent();
     }
 });

To patch the bug in DerivedClass.method, the typical solution is to create an override:

 Ext.define('App.paches.DerivedClass', {
     override: 'Ext.some.DerivedClass',

     method: function () {
         console.log('Fixed');

         // ... logic but with bug fixed ...

         this.callSuper();
     }
 });

The patch method cannot use callParent to call the superclass method since that would call the overridden method containing the bug. In other words, the above patch would only produce "Fixed" then "Good" in the console log, whereas, using callParent would produce "Fixed" then "Bad" then "Good".

Available since: Ext JS 4.1.3

Parameters

  • args : Array/Arguments

    The arguments, either an array or the arguments object from the current method, for example: this.callSuper(arguments)

Returns

  • Object

    Returns the result of calling the superclass method

...

Available since: 4.1.1

...

Available since: 4.1.0

Parameters

Returns the initial configuration passed to constructor when instantiating this class. ...

Returns the initial configuration passed to constructor when instantiating this class.

Available since: 4.1.0

Parameters

  • name : String (optional)

    Name of the config option to return.

Returns

  • Object/Mixed

    The full config object or a single config value when name parameter specified.

...

Available since: 4.1.0

Parameters

( config ) : Ext.Basechainableprotected
Initialize configuration for this class. ...

Initialize configuration for this class. a typical example:

Ext.define('My.awesome.Class', {
    // The default config
    config: {
        name: 'Awesome',
        isAwesome: true
    },

    constructor: function(config) {
        this.initConfig(config);
    }
});

var awesome = new My.awesome.Class({
    name: 'Super Awesome'
});

alert(awesome.getName()); // 'Super Awesome'

Available since: 4.0.0

Parameters

Returns

( names, callback, scope )private
...

Available since: 4.1.0

Parameters

( config, applyIfNotSet ) : Ext.Basechainableprivate
...

Available since: 4.0.0

Parameters

Returns

Get the reference to the class from which this object was instantiated. ...

Get the reference to the class from which this object was instantiated. Note that unlike self, this.statics() is scope-independent and it always returns the class from which it was called, regardless of what this points to during run-time

Ext.define('My.Cat', {
    statics: {
        totalCreated: 0,
        speciesName: 'Cat' // My.Cat.speciesName = 'Cat'
    },

    constructor: function() {
        var statics = this.statics();

        alert(statics.speciesName);     // always equals to 'Cat' no matter what 'this' refers to
                                        // equivalent to: My.Cat.speciesName

        alert(this.self.speciesName);   // dependent on 'this'

        statics.totalCreated++;
    },

    clone: function() {
        var cloned = new this.self;                      // dependent on 'this'

        cloned.groupName = this.statics().speciesName;   // equivalent to: My.Cat.speciesName

        return cloned;
    }
});


Ext.define('My.SnowLeopard', {
    extend: 'My.Cat',

    statics: {
        speciesName: 'Snow Leopard'     // My.SnowLeopard.speciesName = 'Snow Leopard'
    },

    constructor: function() {
        this.callParent();
    }
});

var cat = new My.Cat();                 // alerts 'Cat', then alerts 'Cat'

var snowLeopard = new My.SnowLeopard(); // alerts 'Cat', then alerts 'Snow Leopard'

var clone = snowLeopard.clone();
alert(Ext.getClassName(clone));         // alerts 'My.SnowLeopard'
alert(clone.groupName);                 // alerts 'Cat'

alert(My.Cat.totalCreated);             // alerts 3

Available since: 4.0.0

Returns

Defined By

Static methods

( config )privatestatic
...

Available since: 4.1.1

Parameters

( members )chainableprivatestatic
...

Available since: 4.1.1

Parameters

( name, member )chainableprivatestatic
...

Available since: 4.1.1

Parameters

( members )chainablestatic
Add methods / properties to the prototype of this class. ...

Add methods / properties to the prototype of this class.

Ext.define('My.awesome.Cat', {
    constructor: function() {
        ...
    }
});

 My.awesome.Cat.addMembers({
     meow: function() {
        alert('Meowww...');
     }
 });

 var kitty = new My.awesome.Cat;
 kitty.meow();

Available since: 4.1.0

Parameters

( members ) : Ext.Basechainablestatic
Add / override static properties of this class. ...

Add / override static properties of this class.

Ext.define('My.cool.Class', {
    ...
});

My.cool.Class.addStatics({
    someProperty: 'someValue',      // My.cool.Class.someProperty = 'someValue'
    method1: function() { ... },    // My.cool.Class.method1 = function() { ... };
    method2: function() { ... }     // My.cool.Class.method2 = function() { ... };
});

Available since: 4.0.2

Parameters

Returns

( xtype )chainableprivatestatic
...

Available since: 4.1.1

Parameters

( fromClass, members ) : Ext.Basechainableprivatestatic
Borrow another class' members to the prototype of this class. ...

Borrow another class' members to the prototype of this class.

Ext.define('Bank', {
    money: '$$$',
    printMoney: function() {
        alert('$$$$$$$');
    }
});

Ext.define('Thief', {
    ...
});

Thief.borrow(Bank, ['money', 'printMoney']);

var steve = new Thief();

alert(steve.money); // alerts '$$$'
steve.printMoney(); // alerts '$$$$$$$'

Available since: 4.0.2

Parameters

  • fromClass : Ext.Base

    The class to borrow members from

  • members : Array/String

    The names of the members to borrow

Returns

Create a new instance of this Class. ...

Create a new instance of this Class.

Ext.define('My.cool.Class', {
    ...
});

My.cool.Class.create({
    someConfig: true
});

All parameters are passed to the constructor of the class.

Available since: 4.0.2

Returns

Overrides: Ext.layout.Layout.create

( alias, origin )static
Create aliases for existing prototype methods. ...

Create aliases for existing prototype methods. Example:

Ext.define('My.cool.Class', {
    method1: function() { ... },
    method2: function() { ... }
});

var test = new My.cool.Class();

My.cool.Class.createAlias({
    method3: 'method1',
    method4: 'method2'
});

test.method3(); // test.method1()

My.cool.Class.createAlias('method5', 'method3');

test.method5(); // test.method3() -> test.method1()

Available since: 4.0.2

Parameters

( config )privatestatic
...

Available since: 4.1.1

Parameters

Get the current class' name in string format. ...

Get the current class' name in string format.

Ext.define('My.cool.Class', {
    constructor: function() {
        alert(this.self.getName()); // alerts 'My.cool.Class'
    }
});

My.cool.Class.getName(); // 'My.cool.Class'

Available since: 4.0.4

Returns

( )deprecatedstatic
Adds members to class. ...

Adds members to class.

Available since: 4.0.2

This method has been deprecated since 4.1

Use addMembers instead.

( name, mixinClass )chainableprivatestatic
Used internally by the mixins pre-processor ...

Used internally by the mixins pre-processor

Available since: 4.1.1

Parameters

( fn, scope )chainableprivatestatic
...

Available since: 4.1.1

Parameters

( members ) : Ext.Basechainabledeprecatedstatic
Override members of this class. ...

Override members of this class. Overridden methods can be invoked via callParent.

Ext.define('My.Cat', {
    constructor: function() {
        alert("I'm a cat!");
    }
});

My.Cat.override({
    constructor: function() {
        alert("I'm going to be a cat!");

        this.callParent(arguments);

        alert("Meeeeoooowwww");
    }
});

var kitty = new My.Cat(); // alerts "I'm going to be a cat!"
                          // alerts "I'm a cat!"
                          // alerts "Meeeeoooowwww"

As of 4.1, direct use of this method is deprecated. Use Ext.define instead:

Ext.define('My.CatOverride', {
    override: 'My.Cat',
    constructor: function() {
        alert("I'm going to be a cat!");

        this.callParent(arguments);

        alert("Meeeeoooowwww");
    }
});

The above accomplishes the same result but can be managed by the Ext.Loader which can properly order the override and its target class and the build process can determine whether the override is needed based on the required state of the target class (My.Cat).

Available since: 4.0.2

This method has been deprecated since 4.1.0

Use Ext.define instead

Parameters

  • members : Object

    The properties to add to this class. This should be specified as an object literal containing one or more properties.

Returns

...

Available since: 4.1.1