Can two chaincode interact with each other

Question

I have two applications that use two different chaincodes. Now for one function to work, I need one chaincode to interact with another chaincode.. I have done this in Ethereum but now I am using Hyperledger and want to implement this.. Is this possible? If yes, then how?

Answer 1

Yes, it is possible for two chaincodes to interact with each other.. You can use the following API of ChaincodeStubInterface to do it:
https://godoc.org/github.com/hyperledger/fabric/core/chaincode/shim

eg:

// InvokeChaincode locally calls the specified chaincode `Invoke` using the
// same transaction context; that is, chaincode calling chaincode doesn't
// create a new transaction message.
// If the called chaincode is on the same channel, it simply adds the called
// chaincode read set and write set to the calling transaction.
// If the called chaincode is on a different channel,
// only the Response is returned to the calling chaincode; any PutState calls
// from the called chaincode will not have any effect on the ledger; that is,
// the called chaincode on a different channel will not have its read set
// and write set applied to the transaction. Only the calling chaincode's
// read set and write set will be applied to the transaction. Effectively
// the called chaincode on a different channel is a `Query`, which does not
// participate in state validation checks in subsequent commit phase.
// If `channel` is empty, the caller's channel is assumed.
InvokeChaincode(chaincodeName string, args [][]byte, channel string) pb.Response

You can use it like this:

response := stub.InvokeChaincode(chaincodeName, chainCodeArgs, channelName)

Answer 2

Yes, two chaincodes can interact with each other. To do this, one chaincode has to invoke the other chaincode. Here's a sample code that shows how to do it:

func (stub *TestAPIStub) InvokeChaincode(chaincode1 string, args [][]byte, channel string) pb.Response {
   return pb.Response{}
}