| """ |
| Example code to update metadata as part of TRANSFER tx |
| |
| stage 1. Alice creates an asset and sets Bob as the owner with price=100 |
| stage 2. Bob transfers the asset to Alice with price=200 |
| stage 3. Alice transfers the asset to Alice with price=300 (only metadata is changed) |
| stage 4. Alice transfers the asset to Alice with price=400 (only metadata is changed) |
| |
| Print the fulfilled_transfer_tx or its equivalent to see the tx items |
| """ |
| #%% |
| |
| from resdb_driver import Resdb |
| from resdb_driver.transaction import Transaction |
| from copy import deepcopy |
| |
| db_root_url = "https://resdb.free.beeceptor.com" |
| |
| db = Resdb(db_root_url) |
| from resdb_driver.crypto import generate_keypair |
| |
| alice, bob = generate_keypair(), generate_keypair() |
| #%% |
| # Stage 1 |
| # create a digital asset for Alice |
| game_boy_token = { |
| "data": { |
| "token_for": {"game_boy": {"serial_number": "LR35902"}}, |
| "description": "Time share token. Each token equals one hour of usage.", |
| }, |
| } |
| |
| #%% |
| # prepare the transaction with the digital asset and issue 1 token for Bob |
| prepared_token_tx = db.transactions.prepare( |
| operation="CREATE", |
| signers=alice.public_key, |
| recipients=[([bob.public_key], 1)], |
| asset=game_boy_token, |
| ) |
| |
| prepared_token_tx["metadata"] = {"price": "100"} #metadata has to be a dict |
| #%% |
| # fulfill the tnx |
| fulfilled_token_tx = db.transactions.fulfill( |
| prepared_token_tx, private_keys=alice.private_key |
| ) |
| |
| |
| #%% stage 2 |
| transfer_asset = {"id": fulfilled_token_tx["id"]} |
| output_index = 0 |
| output = fulfilled_token_tx["outputs"][output_index] |
| transfer_input = { |
| "fulfillment": output["condition"]["details"], |
| "fulfills": {"output_index": output_index, "transaction_id": transfer_asset["id"]}, |
| "owners_before": output["public_keys"], |
| } |
| |
| #%% |
| |
| prepared_transfer_tx = db.transactions.prepare( |
| operation="TRANSFER", |
| asset=transfer_asset, |
| inputs=transfer_input, |
| metadata={"price": "200"}, |
| recipients=[([alice.public_key], 1)], |
| ) |
| |
| #%% |
| |
| fulfilled_transfer_tx = db.transactions.fulfill( |
| prepared_transfer_tx, private_keys=bob.private_key |
| ) |
| |
| # stage 3 |
| # Change the metadata |
| #%% |
| transfer_asset = {"id": fulfilled_token_tx["id"]} |
| output_index = 0 |
| output = fulfilled_transfer_tx["outputs"][output_index] |
| transfer_input = { |
| "fulfillment": output["condition"]["details"], |
| "fulfills": {"output_index": output_index, "transaction_id": fulfilled_transfer_tx["id"]}, |
| "owners_before": output["public_keys"], |
| } |
| |
| prepared_transfer_tx = db.transactions.prepare( |
| operation="TRANSFER", |
| asset=transfer_asset, |
| inputs=transfer_input, |
| metadata={"price": "300"}, |
| recipients=[([alice.public_key], 1)], |
| ) |
| fulfilled_transfer_tx = db.transactions.fulfill( |
| prepared_transfer_tx, private_keys=alice.private_key |
| ) |
| |
| # stage 4 |
| # chage the metadata again |
| |
| #%% |
| transfer_asset = {"id": fulfilled_token_tx["id"]} |
| output_index = 0 |
| output = fulfilled_transfer_tx["outputs"][output_index] |
| transfer_input = { |
| "fulfillment": output["condition"]["details"], |
| "fulfills": {"output_index": output_index, "transaction_id": fulfilled_transfer_tx["id"]}, |
| "owners_before": output["public_keys"], |
| } |
| |
| prepared_transfer_tx = db.transactions.prepare( |
| operation="TRANSFER", |
| asset=transfer_asset, |
| inputs=transfer_input, |
| metadata={"price": "400"}, |
| recipients=[([alice.public_key], 1)], |
| ) |
| fulfilled_transfer_tx = db.transactions.fulfill( |
| prepared_transfer_tx, private_keys=alice.private_key |
| ) |
| |
| |
| #%% |
| sent_transfer_tx = db.transactions.send_commit(fulfilled_transfer_tx) # use this to commit whenever required |
| |