Create file dynamically as File object and then publish - silverstripe-4

Question

It's evidently a little more complicated to create a file dynamically in SS4
$folder = Folder::find_or_make('Cards');
$filename = 'myimage.jpg';
$contents = file_get_contents('http://example.com/image.jpg');
$pathToFile = Controller::join_links(Director::baseFolder(), ASSETS_DIR, $folder->Title, $filename);
file_put_contents($pathToFile, $contents);
$image = Image::create();
$image->ParentID = $folder->ID;
$image->Title = "My title";
$image->Name = $filename;
$image->FileFilename = 'Cards/' . $filename;
$image->write();
Member::actAs(Member::get()->first(), function() use ($image, $folder) {
if (!$image->isPublished()) {
$image->publishFile();
$image->publishSingle();
}
if (!$folder->isPublished()) {
$folder->publishSingle();
}
});
The above, creates the file as expected in /assets/Cards/myimage.jpg and publishes it fine
However all previews are blank, so it's obviously not finding the file:
Any idea what I missed in creating the Image object?

Answer 1

This should work:
$folder = Folder::find_or_make('Cards');
$contents = file_get_contents('http://example.com/image.jpg');
$img = Image::create();
$img->setFromString($contents, 'image.jpg');
$img->ParentID = $parent->ID;
$img->write();
// This is needed to build the thumbnails
\SilverStripe\AssetAdmin\Controller\AssetAdmin::create()->generateThumbnails($img);
$img->publishSingle();
FYI: $img->Filename no longer exists. An Image or File object have a File property, which is a composite field of type DBFile. This composite fields contains the filename, hash and a variant…
So you should use the composite field to address these fields.