Class Ext.data.Model

A Model represents some object that your application manages. For example, one might define a Model for Users, Products, Cars, or any other real-world object that we want to model in the system. Models are registered via the model manager, and are used by stores, which are in turn used by many of the data-bound components in Ext.

Models are defined as a set of fields and any arbitrary methods and properties relevant to the model. For example:

Ext.regModel('User', {
    fields: [
        {name: 'name',  type: 'string'},
        {name: 'age',   type: 'int'},
        {name: 'phone', type: 'string'},
        {name: 'alive', type: 'boolean', defaultValue: true}
    ],

    changeName: function() {
        var oldName = this.get('name'),
            newName = oldName + " The Barbarian";

        this.set('name', newName);
    }
});

The fields array is turned into a MixedCollection automatically by the ModelMgr, and all other functions and properties are copied to the new Model's prototype.

Now we can create instances of our User model and call any model logic we defined:

var user = Ext.ModelMgr.create({
    name : 'Conan',
    age  : 24,
    phone: '555-555-5555'
}, 'User');

user.changeName();
user.get('name'); //returns "Conan The Barbarian"

Validations

Models have built-in support for validations, which are executed against the validator functions in Ext.data.validations (see all validation functions). Validations are easy to add to models:

Ext.regModel('User', {
    fields: [
        {name: 'name',     type: 'string'},
        {name: 'age',      type: 'int'},
        {name: 'phone',    type: 'string'},
        {name: 'gender',   type: 'string'},
        {name: 'username', type: 'string'},
        {name: 'alive',    type: 'boolean', defaultValue: true}
    ],

    validations: [
        {type: 'presence',  field: 'age'},
        {type: 'length',    field: 'name',     min: 2},
        {type: 'inclusion', field: 'gender',   list: ['Male', 'Female']},
        {type: 'exclusion', field: 'username', list: ['Admin', 'Operator']},
        {type: 'format',    field: 'username', matcher: /([a-z]+)[0-9]{2,3}/}
    ]
});

The validations can be run by simply calling the validate function, which returns a Ext.data.Errors object:

var instance = Ext.ModelMgr.create({
    name: 'Ed',
    gender: 'Male',
    username: 'edspencer'
}, 'User');

var errors = instance.validate();

Associations

Models can have associations with other Models via belongsTo and hasMany associations. For example, let's say we're writing a blog administration application which deals with Users, Posts and Comments. We can express the relationships between these models like this:

Ext.regModel('Post', {
    fields: ['id', 'user_id'],

    belongsTo: 'User',
    hasMany  : {model: 'Comment', name: 'comments'}
});

Ext.regModel('Comment', {
    fields: ['id', 'user_id', 'post_id'],

    belongsTo: 'Post'
});

Ext.regModel('User', {
    fields: ['id'],

    hasMany: [
        'Post',
        {model: 'Comment', name: 'comments'}
    ]
});

See the docs for Ext.data.BelongsToAssociation and Ext.data.HasManyAssociation for details on the usage and configuration of associations. Note that associations can also be specified like this:

Ext.regModel('User', {
    fields: ['id'],

    associations: [
        {type: 'hasMany', model: 'Post',    name: 'posts'},
        {type: 'hasMany', model: 'Comment', name: 'comments'}
    ]
});