Problem with $belongs_many_many

[webspilka]

Hi
Next code in class BlogEntry extends DataObject:

    public static $belongs_many_many_extraFields=array(
        'BlogCategorys'=>array(
            'SortOrder'=>'Int'
        )
    );

not created 'SortOrder' column

Problem is solved with the following code:

class BlogCategory extends Page {

    private static $many_many = array(
            'BlogEntrys' => 'BlogEntry'
        );

    public static $many_many_extraFields=array(
        'BlogEntrys'=>array(
            'SortOrder'=>'Int'
        )
    );
}

class BlogEntry extends DataObject {

    private static $belongs_many_many = array(
        'BlogCategorys' => 'BlogCategory'
    );

   public function getCMSFields() {
   ...
        $gridFieldConfig = GridFieldConfig_RelationEditor::create();
        $gridFieldConfig->removeComponentsByType('GridFieldAddNewButton');

        $gridFieldConfig->addComponent(new GridFieldSortableRows('SortOrder'));

        $gridfield = new GridField("BlogCategorys", "Blog Categorys", $this->BlogCategorys(), $gridFieldConfig);
        $fields->addFieldToTab('Root.BlogCategorys', $gridfield);
   ...
   }

    public function BlogCategorys() {
        return $this->getManyManyComponents('BlogCategorys')->sort('SortOrder');
    }
}

The problem with this code has been solved.
But why is not working with $belongs_many_many_extraFields ?

[UndefinedOffset]

Well this is really an issue with SilverStripe's ORM not SortableGridField, my guess the idea here is that you define the extra fields on the object that defines the many_many relationship. I''m pretty sure the core of SilverStripe even looks for a belongs_many_many_extraFields. My recommendation is to have a look at the documentation http://doc.silverstripe.org/framework/en/reference/dataobject. If you think that this is a feature the SilverStripe core is missing try raising it there silverstripe/silverstripe-framework