Hello guys,

Need a little help getting some IDs from a relation table.

The below code is what i use for a home page. In the administration you can now select multible pages, and the IDs are saved to the relation table "ForsidePage_PreviewList".
i need to use the IDs from this table in my filter in "ForsidePage_Controller" in the function "showPreviews", and not the hardcoded ...".ID IN (8,9,10)" ...

How can this be done?

class ForsidePage extends Page {
static $db = array();

static $has_one = array();

public static $many_many = array(
'PreviewList' => 'SiteTree'
);

function getCMSFields() {
$fields = parent::getCMSFields();
$fields->addFieldToTab('Root.Content.Previews', new TreeMultiselectField( 'PreviewList', 'Preview Sites', 'SiteTree'));

return $fields;
}
}

class ForsidePage_Controller extends Page_Controller {
function showPreviews() {
$myIds = "";// Query to get IDs from the relation table
$records = DataObject::get("WithPreviewPage", "`WithPreviewPage`.ID IN (8,9,10)");
return ($records);
}

}

What you're looking for is a method on the relational getter called getIdList(). To get an array of the IDs of the relation, simply call that method like so (on your controller):

$this->dataRecord->getManyManyComponents('PreviewList')->getIdList();

Then you can just implode the array into a comma separated ID string ready for your SQL query.

Sean