Manual Constructing and Signing of Transactions

Warning

This is a low level class. Do not use this class unless you know what you are doing!

Note

This class is under development and meant for people that are looking into the low level construction and signing of various transactions.

Loading Transactions Class

We load the class for manual transaction construction via:

from pistonbase import transactions

Construction

Now we can use the predefined transaction formats, e.g. vote or comment as follows:

  1. define the expiration time
  2. define a JSON object that contains all data for that transaction
  3. load that data into the corresponding operations class
  4. collect multiple operations
  5. get some blockchain parameters to prevent replay attack
  6. Construct the actual transaction from the list of operations
  7. sign the transaction with the corresponding private key(s)

Example A: Vote

expiration = transactions.formatTimeFromNow(60)
op = transactions.Vote(
    **{"voter": voter,
       "author": message["author"],
       "permlink": message["permlink"],
       "weight": int(weight)}
)
ops    = [transactions.Operation(op)]
ref_block_num, ref_block_prefix = transactions.getBlockParams(rpc)
tx     = transactions.Signed_Transaction(ref_block_num=ref_block_num,
                                         ref_block_prefix=ref_block_prefix,
                                         expiration=expiration,
                                         operations=ops)
tx = tx.sign([wif])

Example A: Comment

# Expiration time 60 seconds in the future
expiration = transactions.formatTimeFromNow(60)
op = transactions.Comment(
    **{"parent_author": parent_author,
       "parent_permlink": parent_permlink,
       "author": author,
       "permlink": postPermlink,
       "title": postTitle,
       "body": postBody,
       "json_metadata": ""}
)
ops    = [transactions.Operation(op)]
ref_block_num, ref_block_prefix = transactions.getBlockParams(rpc)
tx     = transactions.Signed_Transaction(ref_block_num=ref_block_num,
                                         ref_block_prefix=ref_block_prefix,
                                         expiration=expiration,
                                         operations=ops)
tx = tx.sign([wif])

Broadcasting

For broadcasting, we first need to convert the transactions class into a JSON object. After that, we can braodcast this to the network:

# Convert python class to JSON
tx = transactions.JsonObj(tx)

# Broadcast JSON to network
rpc.broadcast_transaction(tx, api="network_broadcast"):