Class
O.RecordAttribute
Represents an attribute on a record.
"use strict";
( function ( NS, undefined ) {
var instanceOf = function ( value, Type ) {
switch ( typeof value ) {
case 'string':
return Type === String;
case 'boolean':
return Type === Boolean;
case 'number':
return Type === Number;
}
return value instanceof Type;
};
var RecordAttribute = NS.Class({
__setupProperty__: function ( metadata, propKey, object ) {
var attrs = metadata.attrs,
dependents;
if ( !metadata.hasOwnProperty( 'attrs' ) ) {
attrs = metadata.attrs = attrs ? Object.create( attrs ) : {};
}
if ( this.isPrimaryKey ) {
object.constructor.primaryKey = propKey;
// Make the `id` property depend on the primary key.
dependents = metadata.dependents;
if ( !metadata.hasOwnProperty( 'dependents' ) ) {
dependents = metadata.dependents = NS.clone( dependents );
metadata.allDependents = {};
}
( dependents[ propKey ] ||
( dependents[ propKey ] = [] ) ).push( 'id' );
}
attrs[ this.key || propKey ] = propKey;
},
__teardownProperty__: function ( metadata, propKey ) {
metadata.attrs[ this.key || propKey ] = null;
},Constructor
O.RecordAttribute( mixin )
Parameters
| mixin | Object Optional Override the default properties. |
|---|
init: function ( mixin ) {
NS.extend( this, mixin );
},Private Property
O.RecordAttribute#isProperty
- Boolean
- private
Record attributes are computed properties.
isProperty: true,Private Property
O.RecordAttribute#isVolatile
- Boolean
- private
Record attributes should be cached.
isVolatile: false,Private Property
O.RecordAttribute#isSilent
- Boolean
- private
Store will handle firing computedPropertyIsChanged on record.
isSilent: true,Property
O.RecordAttribute#noSync
- Boolean
If set to true, changes will not be propagated back to the source.
noSync: false,Property
O.RecordAttribute#Type
- Constructor
If a type is set and it has a fromJSON method, this will be used to convert values from the underlying data object when the attribute is fetched.
Type: null,Property
O.RecordAttribute#isNullable
- Boolean
If false, attempts to set null for the value will throw an error.
isNullable: true,Property
O.RecordAttribute#key
- {String|null}
The key to use on the JSON object for this attribute. If not set, will use the same key as the property name on the record.
key: null,Property
O.RecordAttribute#isPrimaryKey
- Boolean
If true, this is the primary key for the record.
isPrimaryKey: false,Method
O.RecordAttribute#willSet( propValue, propKey )
This function is used to check the value being set is permissible. By default, it checks that the value is not null (or the <#isNullable> property is true), and that the value is of the correct type (if the <#Type> property is set). An error is thrown if the value is of a different type.
You could override this function to, for example, only allow values that pass a strict validation to be set.
Parameters
| propValue | * The value being set. |
|---|---|
| propKey | String The name of the attribute. |
Returns
Boolean May the value be set?
willSet: function ( propValue, propKey, record ) {
if ( !record.get( 'isEditable' ) ) {
return false;
}
if ( propValue === null ) {
if ( !this.isNullable ) {
return false;
}
}
else if ( this.Type && !instanceOf( propValue, this.Type ) ) {
throw new Error( "Incorrect value type for record attribute" );
}
return true;
},Property
O.RecordAttribute#defaultValue
- *
If the attribute is not set on the underlying data object, the defaultValue will be returned instead. This will also be used to add this attribute to the data object if a new record is created and the attribute is not set.
The value should be of the type specified in O.RecordAttribute#Type.
defaultValue: undefined,Method
O.RecordAttribute#validate( propValue, propKey, record )
Tests whether the value to be set is valid.
Parameters
| propValue | * The value being set. This is the real value, not the serialised version for JSON (if different). |
|---|---|
| propKey | String The name of the attribute on the record. |
| record | O.Record The record on which the value is being set. |
Returns
O.ValidationError An object describing the error if this is not a valid value for the attribute. Otherwise, returns null if the value is valid.
validate: null,Property
O.RecordAttribute#validityDependencies
- String[]|null
Other attributes the validity depends on. The attribute will be revalidated if any of these attributes change. Note, chained dependencies are not automatically calculated; you must explicitly state all dependencies.
NB. This is a list of the names of the attributes as used on the objects, not necessarily that of the underlying keys used in the JSON data object.
validityDependencies: null,Method
O.RecordAttribute#call( record, propValue, propKey )
Gets/sets the attribute.
Parameters
| record | O.Record The record the attribute is being set on or got from. |
|---|---|
| propValue | * The value being set (undefined if just a 'get'). |
| propKey | String The name of the attribute on the record. |
Returns
* The attribute.
call: function ( record, propValue, propKey ) {
var store = record.get( 'store' ),
storeKey = record.get( 'storeKey' ),
data = storeKey ? store.getData( storeKey ) : record._data,
attrKey, attrValue, currentAttrValue, update, Type;
if ( data ) {
attrKey = this.key || propKey;
currentAttrValue = data[ attrKey ];
if ( propValue !== undefined &&
this.willSet( propValue, propKey, record ) ) {
attrValue = propValue && propValue.toJSON ?
propValue.toJSON() : propValue;
if ( !NS.isEqual( attrValue, currentAttrValue ) ) {
if ( storeKey ) {
update = {};
update[ attrKey ] = attrValue;
store.updateData( storeKey, update,
!( this.noSync || record._noSync ) );
store.fire( 'record:user:update', { record: this });
} else {
data[ attrKey ] = attrValue;
record.computedPropertyDidChange( propKey );
if ( this.validate ) {
record.get( 'errorForAttribute' ).set( propKey,
this.validate( propValue, propKey, record ) );
}
}
}
return propValue;
}
Type = this.Type;
}
return currentAttrValue !== undefined ?
currentAttrValue !== null && Type && Type.fromJSON ?
Type.fromJSON( currentAttrValue ) : currentAttrValue :
this.defaultValue;
}
});
NS.RecordAttribute = RecordAttribute;Function
O.Record.attr( Type, mixin )
A factory function for creating a new O.RecordAttribute instance. This will set an assert function to verify the correct type is being set whenever the value is set, and that the correct type is used to serialise to/from primitive types.
When subclassing O.Record, use this function to create a value for any properties on the record which correspond to properties on the underlying data object. This will automatically set things up so they are fetched from the store and synced to the source.
Parameters
| Type | Constructor The type of the property. |
|---|---|
| mixin | Object Properties to pass to the |
Returns
O.RecordAttribute Getter/setter for that record attribute.
NS.Record.attr = function ( Type, mixin ) {
if ( !mixin ) { mixin = {}; }
if ( Type && !mixin.Type ) { mixin.Type = Type; }
return new RecordAttribute( mixin );
};
}( O ) );