Issue with Matrix afterDelete() and sessions when none is available

[engram-design]

Not so much an issue, but maybe a general discussion on the best approach? The short of the issue is that in Feed Me, when updating an element that has a Matrix field, which in turn has element fields, there's an error being thrown:

session_start(): Cannot send session cookie - headers already sent by (output started at /vendor/yiisoft/yii2/web/Response.php:414) - Session.php:137

This is only when triggering a task through the queue. Running it directly (with a logged in session) works just fine.

After much trial an error, I've isolated it to the following code in elements/MatrixBlock.php:

public function afterDelete()
{
    if (!Craft::$app->getRequest()->getIsConsoleRequest()) {
        // Tell the browser to forget about this block
        $session = Craft::$app->getSession();
        $session->addAssetBundleFlash(MatrixAsset::class);
        $session->addJsFlash('Craft.MatrixInput.forgetCollapsedBlockId('.$this->id.');');
    }

    parent::afterDelete();
}

And I can see why this would happen, and why its throwing the error. So rather than suggest modifying this function (even with a try-catch), is there some may to masquerade requests as if they were console commands? Or would there be a better approach for this?

Apologies if this is not the right platform for discussion.

[brandonkelly]

I just fixed this yesterday ;) 27eaf6e (original issue reported is #2813)

[engram-design]

Awesome, sorry didn't even see that! Thanks @brandonkelly

[engram-design]

@brandonkelly Hate to bring this issue up from the dead, but seems like its come back!

See https://github.com/craftcms/cms/blob/develop/src/services/Matrix.php#L720 or:

if (!Craft::$app->getRequest()->getIsConsoleRequest() && !empty($collapsedBlockIds)) {
    ...
}

Referencing 27eaf6e and add && !Craft::$app->getResponse()->isSent to the appropriate line fixes this.

I have submitted a PR for consideration - #3217