Alternate names
Ext.data.AssociationHierarchy
Ext.BaseExt.data.association.AssociationRequires
Subclasses
Files
Guide
Using ModelsAssociations enable you to express relationships between different Models. Let's say we're writing an ecommerce system where Users can make Orders - there's a relationship between these Models that we can express like this:
Ext.define('MyApp.model.User', {
extend: 'Ext.data.Model',
config: {
fields: ['id', 'name', 'email'],
hasMany: {
model: 'MyApp.model.Order',
name: 'orders'
}
}
});
Ext.define('MyApp.model.Order', {
extend: 'Ext.data.Model',
config: {
fields: ['id', 'user_id', 'status', 'price'],
belongsTo: 'MyApp.model.User'
}
});
We've set up two models - User and Order - and told them about each other. You can set up as many associations on each Model as you need using the two default types - hasMany and belongsTo. There's much more detail on the usage of each of those inside their documentation pages. If you're not familiar with Models already, there is plenty on those too.
Further Reading
Self-associating Models
We can also have models that create parent/child associations between the same type. Below is an example, where groups can be nested inside other groups:
// Server Data
{
"groups": {
"id": 10,
"parent_id": 100,
"name": "Main Group",
"parent_group": {
"id": 100,
"parent_id": null,
"name": "Parent Group"
},
"nested" : {
"child_groups": [{
"id": 2,
"parent_id": 10,
"name": "Child Group 1"
},{
"id": 3,
"parent_id": 10,
"name": "Child Group 2"
},{
"id": 4,
"parent_id": 10,
"name": "Child Group 3"
}]
}
}
}
// Client code
Ext.define('MyApp.model.Group', {
extend: 'Ext.data.Model',
config: {
fields: ['id', 'parent_id', 'name'],
proxy: {
type: 'ajax',
url: 'data.json',
reader: {
type: 'json',
root: 'groups'
}
},
associations: [{
type: 'hasMany',
model: 'MyApp.model.Group',
primaryKey: 'id',
foreignKey: 'parent_id',
autoLoad: true,
associationKey: 'nested.child_groups' // read child data from nested.child_groups
}, {
type: 'belongsTo',
model: 'MyApp.model.Group',
primaryKey: 'id',
foreignKey: 'parent_id',
associationKey: 'parent_group' // read parent data from parent_group
}]
}
});
Ext.onReady(function(){
MyApp.model.Group.load(10, {
success: function(group){
console.log(group.getGroup().get('name'));
group.groups().each(function(rec){
console.log(rec.get('name'));
});
}
});
});
Config options
Required config options
The full class name or reference to the class that the ownerModel is being associated with. This is a required configuration on every association.
Optional config options
The name for the associated model. This defaults to the last part of the class name of the associatedModel.
The name of the property in the data to read the association from. Defaults to the associatedName plus '_id'.
The name for the owner model. This defaults to the last part of the class name of the ownerModel.
The name of the primary key on the associated model. In general this will be the Ext.data.Model.idProperty of the Model.
Defaults to: 'id'
Properties
Instance properties
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'
Methods
Instance methods
Call the original method that was previously overridden with override,
This method is deprecated as callParent does the same thing.
Ext.define('My.Cat', {
constructor: function() {
alert("I'm a cat!");
}
});
My.Cat.override({
constructor: function() {
alert("I'm going to be a cat!");
var instance = this.callOverridden();
alert("Meeeeoooowwww");
return instance;
}
});
var kitty = new My.Cat(); // alerts "I'm going to be a cat!"
// alerts "I'm a cat!"
// alerts "Meeeeoooowwww"
Parameters
- args : Array/Arguments
The arguments, either an array or the
argumentsobject 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. 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.
Parameters
- args : Array/Arguments
The arguments, either an array or the
argumentsobject from the current method, for example:this.callParent(arguments)
Returns
- Object
Returns the result of calling the parent 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".
Parameters
- args : Array/Arguments
The arguments, either an array or the
argumentsobject from the current method, for example:this.callSuper(arguments)
Returns
- Object
Returns the result of calling the superclass method
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'
Parameters
- instanceConfig : Object
Returns
- Object
mixins The mixin prototypes as key - value pairs
Fires
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
Returns
Static methods
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();
Parameters
- members : Object
Add / override static properties of this class.
Ext.define('My.cool.Class', {
// this.se
});
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() { ... };
});
Parameters
- members : Object
Returns
- Ext.Base
this
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 '$$$$$$$'
Parameters
- fromClass : Ext.Base
The class to borrow members from
- members : Array/String
The names of the members to borrow
Returns
- Ext.Base
this
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()
Parameters
- alias : String/Object
The new method name, or an object to set multiple aliases. See flexSetter
- origin : String/Object
The original method name
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'
Returns
- String
className
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!");
var instance = this.callParent(arguments);
alert("Meeeeoooowwww");
return instance;
}
});
var kitty = new My.Cat(); // alerts "I'm going to be a cat!"
// alerts "I'm a cat!"
// alerts "Meeeeoooowwww"
As of 2.1, 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!");
var instance = this.callParent(arguments);
alert("Meeeeoooowwww");
return instance;
}
});
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).
This method has been deprecated since 2.1.0
Please 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
- Ext.Base
this class