title: Extending #

Adding custom link types #

Sometimes you might have custom DataObject types that you would like CMS users to be able to create Links to. This can be achieved by adding a DataExtension to the Link DataObject, see the below example for making Product objects Linkable.


use SilverStripe\Forms\FieldList;
use SilverStripe\Forms\DropdownField;
use SilverStripe\ORM\DataExtension;
use UncleCheese\DisplayLogic\Forms\Wrapper;

class CustomLinkExtension extends DataExtension
{
    private static $has_one = [
        'Product' => 'Product',
    ];

    /**
     * A map of object types that can be linked to
     * Custom dataobjects can be added to this
     *
     * @var array
     **/
    private static $types = [
        'Product' => 'A Product on this site',
    ];

    public function updateCMSFields(FieldList $fields)
    {
        // Add a dropdown field containing your ProductList
        $fields->addFieldToTab(
            'Root.Main',
            Wrapper::create(
                DropdownField::create(
                    'ProductID',
                    'Product',
                    Product::get()->map('ID', 'Title')->toArray()
                )
                ->setHasEmptyDefault(true)
            )->displayIf('Type')->isEqualTo('Product')->end()
        );
    }

    /**
     * Update LinkURL
     */
    public function updateLinkURL(&$linkURL)
    {
        $owner = $this->owner;
        if ($owner->Type == 'Product') {
            $linkURL = ''; // Product url
        }
    }

In your config.yml

gorriecoe\Link\Models\Link:
  extensions:
    - CustomLinkExtension

Working examples #

The following modules enhance link but can also be used as working examples for what is possible.