I implemented the following to make it possible to mint Birds as NFTs from the Flutter Bird App.

flutter_bird_image_server

• Implement flutter_bird_image_server
  • A bird image is generated based on the received tokenID.
  • The same data url will always be returned for the same tokenId.
  • Currently, the hosting is on Vercel, and there are restrictions on using the file system. Therefore, the generated image is not saved on the server, but the data URL is included in the response and returned.
  • The image size of bird is around 10KB at most, so it does not put a large load on the system.
• flutter_bird_image_server/create_birds/create_data.js and the generate_image and generate_metadata files it calls use the files that were already in the original repository. Only the parts related to fs have been deleted.
  • https://github.com/Tonnanto/flutter-bird/tree/master/flutter_bird_skins/scripts
• mint_full_onchain_bird/mint_random_skin.js is a script for manually minting bird and will not be called when minting from the flutter app.

flutter_bird_app

• Implement mint button on flutter app
  • I added a button to mint bird on flutter.
  • This receives the data url from the image_server and calls mint and appendUri of the FlutterBirdsSkins contract.
• _createAndUploadUri
  • https://github.com/Finschia/flutter-bird/compare/master...Finschia:flutter-bird:mint-bird-from-liff?expand=1#diff-21f69922bf92a0ace86a77db5c1db6d4c9f67f3ea7adf9b3a8ca96e96ab264feR116
  • The image is retrieved from the server using the tokenId as a key, and the contract's appendUri is executed.
  • Currently, the game operator executes appendUri using a private key. This specification is merely a PoC to verify whether tx can be executed in a format different from mint, and is not meaningful.
• mintRandomSkin
  • https://github.com/Finschia/flutter-bird/compare/master...Finschia:flutter-bird:mint-bird-from-liff?expand=1#diff-21f69922bf92a0ace86a77db5c1db6d4c9f67f3ea7adf9b3a8ca96e96ab264feR35
  • Users will use 1 KLAY to mint an NFT.

flutter_bird_skins

• Implement appendUri
  • The image data url is set to the tokenURI of the NFT.
  • This allows you to retrieve the image data by simply querying the contract's tokenURI.
  • The image is not stored anywhere on the file server and exists entirely on-chain.
  • Therefore, we no longer use IPFS.
• lib contracts
  • The contracts in flutter_bird_skins/lib use already implemented contracts around storage.

LIFF URL

• You can try out mint with the LIFF below.
  • https://liff.line.me/2005806035-kp4pmzW2