Represents a one-to-many relationship between two models. Usually created indirectly via a model definition:
+ * +
+Ext.define('Product', {
+ extend: 'Ext.data.Model',
+ fields: [
+ {name: 'id', type: 'int'},
+ {name: 'user_id', type: 'int'},
+ {name: 'name', type: 'string'}
+ ]
+});
+
+Ext.define('User', {
+ extend: 'Ext.data.Model',
+ fields: [
+ {name: 'id', type: 'int'},
+ {name: 'name', type: 'string'}
+ ],
+ // we can use the hasMany shortcut on the model to create a hasMany association
+ hasMany: {model: 'Product', name: 'products'}
+});
+Above we created Product and User models, and linked them by saying that a User hasMany Products. This gives + * us a new function on every User instance, in this case the function is called 'products' because that is the name + * we specified in the association configuration above.
+ * + *This new function returns a specialized {@link Ext.data.Store Store} which is automatically filtered to load + * only Products for the given model instance:
+ * +
+//first, we load up a User with id of 1
+var user = Ext.ModelManager.create({id: 1, name: 'Ed'}, 'User');
+
+//the user.products function was created automatically by the association and returns a {@link Ext.data.Store Store}
+//the created store is automatically scoped to the set of Products for the User with id of 1
+var products = user.products();
+
+//we still have all of the usual Store functions, for example it's easy to add a Product for this User
+products.add({
+ name: 'Another Product'
+});
+
+//saves the changes to the store - this automatically sets the new Product's user_id to 1 before saving
+products.sync();
+The new Store is only instantiated the first time you call products() to conserve memory and processing time, + * though calling products() a second time returns the same store instance.
+ * + *Custom filtering
+ * + *The Store is automatically furnished with a filter - by default this filter tells the store to only return + * records where the associated model's foreign key matches the owner model's primary key. For example, if a User + * with ID = 100 hasMany Products, the filter loads only Products with user_id == 100.
+ * + *Sometimes we want to filter by another field - for example in the case of a Twitter search application we may + * have models for Search and Tweet:
+ * +
+Ext.define('Search', {
+ extend: 'Ext.data.Model',
+ fields: [
+ 'id', 'query'
+ ],
+
+ hasMany: {
+ model: 'Tweet',
+ name : 'tweets',
+ filterProperty: 'query'
+ }
+});
+
+Ext.define('Tweet', {
+ extend: 'Ext.data.Model',
+ fields: [
+ 'id', 'text', 'from_user'
+ ]
+});
+
+//returns a Store filtered by the filterProperty
+var store = new Search({query: 'Sencha Touch'}).tweets();
+The tweets association above is filtered by the query property by setting the {@link #filterProperty}, and is + * equivalent to this:
+ * +
+var store = new Ext.data.Store({
+ model: 'Tweet',
+ filters: [
+ {
+ property: 'query',
+ value : 'Sencha Touch'
+ }
+ ]
+});
+
+Ext.define('Group', {
+ extend: 'Ext.data.Model',
+ fields: ['id', 'name'],
+ hasMany: 'User'
+});
+
+Ext.define('User', {
+ extend: 'Ext.data.Model',
+ fields: ['id', 'name', 'group_id'], // refers to the id of the group that this user belongs to
+ belongsTo: 'Group'
+});
+ *
+// This will create a users() method on any Group model instance
+Ext.define('Group', {
+ extend: 'Ext.data.Model',
+ fields: ['id', 'name'],
+ hasMany: 'User'
+});
+var group = new Group();
+console.log(group.users());
+
+// The method to retrieve the users will now be getUserList
+Ext.define('Group', {
+ extend: 'Ext.data.Model',
+ fields: ['id', 'name'],
+ hasMany: {model: 'User', name: 'getUserList'}
+});
+var group = new Group();
+console.log(group.getUserList());
+ *
+associations: [{
+ type: 'hasMany',
+ model: 'User'
+}]
+ *