How to create another contract from another contract using web3

Question

Well I have contract which creates another contract:

contractA{    
    function myMethod(address contractbAddress) payable public{
        address contractcAddress = (new contractC).value(msg.value)(msg.sender,address(this),contractbAddress);
        contractB(contractbAddress).setContract(msg.sender,contractcAddress); 
        confirmEvent(msg.sender,contractcAddress);
    }
}
contractB{
    function setContract(address sender,address contractcAddress){
        ....
    }
}
contractC{
    function contractC(address sender,address contractaAddress,address contractbAddress){
        ....
    }
}

I have contractB's address and contractA's address when I deployed them using truffle migrate.

Now when I will call function myMethod using web3, how will it get to know what is contractC because they no longer have the source code of it?

Answer 1

I'd assume your function myMethod is creating contract C and not B, ie (new contractC) instead.

Since you are generating an event with the address you want

confirmEvent(msg.sender,contractcAddress);

You can listen for that event

contractA.events.confirmEvent.watch((err, ev) => {
    console.log(ev); // contract c address is a parameter of the event
});

Another option is to request the receipt of the transaction that calls myMethod the event should be between the logs of the receipt.