Hands-On Blockchain with Hyperledger

Creating an asset

Now that we can implement our first chaincode function, we will move on and implement a requestTrade function, which will create a new trade agreement with the status REQUESTED and then record that agreement on the ledger.

The implementation of the function is shown in the following snippet. As you will see, in line 9 we verify that the invoker is a member of ImporterOrg and has permission to invoke the function. From lines 13 to 21 we validate and extract the arguments. In line 23, we create a new instance of TradeAgreement initiated with the received arguments. As we learned earlier, the ledger stores values in the form of arrays of bytes. Thus, in line 24 we serialize TradeAgreement with JSON into an array of bytes. In ...