GridFieldEditableColumns does not work with ManyManyThroughList

[ntd]

I just tried to substitute the two occurrences of $list instanceof ManyManyList with ($list instanceof ManyManyList || $list instanceof ManyManyThroughList) but it does not seem to work properly.

Let's pretend to have the following data model:

class Team extends DataObject
{
    private static $many_many = [
        "Supporters" => [
            'through' => TeamSupporter::class,
            'from' => 'Team',
            'to' => 'Supporter',
        ]
    ];
}
class Supporter extends DataObject
{
    private static $belongs_many_many = [
        'Supports' => Team::class,
    ];
}
class TeamSupporter extends DataObject
{
    private static $db = [
        'SomeData' => 'Varchar(10)',
    ];

    private static $has_one = [
        'Team' => Team::class,
        'Supporter' => Supporter::class,
    ];
}

With the following code in Team::getCMSFields (that works properly when SomeData is defined as $many_many_extraFields), I am able to change it (I see the new value in the database) but the form field element is not properly populated (it is always empty):

$config->getComponent>ByType(GridFieldEditableColumns::class)->setDisplayFields([
    'SomeData' => 'A really useful field',
]);

With the following code, the form field is properly populated but it is turned readonly:

$config->getComponent>ByType(GridFieldEditableColumns::class)->setDisplayFields([
    'TeamSupporter.SomeData' => 'A really useful field',
]);

Unfortunately I need to use an explicit through relation to be able to populateDefaults() the extra fields and add some calculated field. If anyone has a better idea I'm all ears.

[ntd]

I just opened a PR that allows me to use the first approach, i.e.:

$config->getComponent>ByType(GridFieldEditableColumns::class)->setDisplayFields([
    'SomeData' => 'A really useful field',
]);

[ntd]

The recently merged #294, together with silverstripe/silverstripe-framework#9192, will allow to properly use dot syntax in this cases, e.g. the following code should work:

$config->getComponent>ByType(GridFieldEditableColumns::class)->setDisplayFields([
    'TeamSupporter.SomeData' => 'A really useful field',
]);

Although not released, one can leverage cweagans/composer-patches to apply unmerged changes, e.g. by having a variant of the following text in your composer.json:

{
  ...
  "require": {
    ...
    "cweagans/composer-patches": "^1.0"
  },
  "extra": {
    "patches": {
      "silverstripe/framework": {
        "Support dot syntax in ManyManyThroughList": "https://github.com/silverstripe/silverstripe-framework/pull/9192.patch"
      }
    }
  }
}

[ntd]

silverstripe/silverstripe-framework#9192 has been recently merged, so I consider this issue solved.