Image and File Uploads

// Uploading and sending are separate steps. Upload first, then put the resulting
// attachment in FMessage::Attachments and send that message.
//
// The SDK takes bytes rather than a path, so the choice of file picker, and the
// platform differences that come with it, stay in your app.
Channel->UploadImage(
  TEXT("image.jpg"),
  ImageBytes,
  [Channel](const FAttachment& Attachment)
  {
    FMessage Message{TEXT("Check this out")};
    Message.Attachments.Add(Attachment);
    Channel->SendMessage(Message);
  });

// Anything that is not an image goes through UploadFile. Prefer UploadImage for
// images: the backend recognises them, may generate a thumbnail, and clients
// render them inline.
Channel->UploadFile(
  TEXT("document.pdf"),
  FileBytes,
  [Channel](const FAttachment& Attachment)
  {
    FMessage Message;
    Message.Attachments.Add(Attachment);
    Channel->SendMessage(Message);
  });

// Both are also available as latent Blueprint nodes: Upload File and Upload Image.

// Uploading outside a channel is not yet available in the Unreal SDK.
// Please let us know if you'd like this feature implemented: https://github.com/GetStream/stream-chat-unreal/issues
// As a workaround, upload through UChatChannel::UploadImage and reuse the returned
// URL when you update the user or channel.
Channel->UploadImage(
  TEXT("avatar.jpg"),
  ImageBytes,
  [](const FAttachment& Attachment)
  {
    const FString ImageUrl = Attachment.GetUrl();
    // Store ImageUrl in the user's or channel's image field
  });

// Routed to the image or the file endpoint depending on the attachment, so you do
// not have to remember which one it was uploaded through.
Channel->DeleteAttachment(
  Attachment,
  [](const bool& bSuccess)
  {
    // Deleted
  });

// Also available as a latent Blueprint node: Delete Attachment.

// The Unreal SDK has no custom uploader hook. Nothing about sending a message
// requires the URL to have come from Stream, so upload to your own CDN and then
// build the attachment yourself.
FAttachment Attachment;
Attachment.Type = EAttachmentType::Image;
Attachment.ImageUrl = TEXT("file-url-to-your-cdn");
Attachment.Title = TEXT("image.jpg");

FMessage Message{TEXT("Message with file attachment")};
Message.Attachments.Add(Attachment);
Channel->SendMessage(Message);