Default values and records
Static default values
The DataObject::$defaults array allows you to specify simple static values to be the default values when a record is created.
A simple example is if you have a dog and by default its bark is "Woof":
namespace App\Model;
use SilverStripe\ORM\DataObject;
class Dog extends DataObject
{
private static $db = [
'Bark' => 'Varchar(10)',
];
private static $defaults = [
'Bark' => 'Woof',
];
}Dynamic default values
In many situations default values need to be dynamically calculated. In order to do this, the DataObject::populateDefaults() method will need to be overloaded.
This method is called whenever a new record is instantiated, and you must be sure to call the method on the parent object!
A simple example is to set a field to the current date and time:
namespace App\Model;
use SilverStripe\ORM\DataObject;
class Dog extends DataObject
{
// ...
/**
* Sets the Date field to the current date.
*/
public function populateDefaults()
{
$this->Date = date('Y-m-d');
parent::populateDefaults();
}
}It's also possible to get the data from any other source, or another object, just by using the usual data retrieval methods. For example:
namespace App\Model;
use SilverStripe\ORM\DataObject;
class Dog extends DataObject
{
// ...
/**
* This method combines the Title of the parent object with the Title of this
* object in the FullTitle field.
*/
public function populateDefaults()
{
$parent = $this->Parent()
if ($parent && $parent->exists()) {
$this->FullTitle = $parent->Title . ': ' . $this->Title;
} else {
$this->FullTitle = $this->Title;
}
parent::populateDefaults();
}
}Static default records
The DataObject::$default_records array allows you to specify default records created on dev/build.
A simple example of this is having a region model and wanting a list of regions created when the site is built:
namespace App\Model;
use SilverStripe\ORM\DataObject;
class Region extends DataObject
{
private static $db = [
'Title' => 'Varchar(45)',
];
private static $default_records = [
['Title' => 'Auckland'],
['Title' => 'Coromandel'],
['Title' => 'Waikato'],
];
}