Hyperledger Composer Playground Execution Error - hyperledger-fabric

Question

I'm trying to create my own crypto currency-'WhizCoin' in Hyperledger Composer Playground.
I have created basic model and script files. 2 Participants- Sender and Receiver, and 1 Asset- Coins, and 1 Transaction- DistributeCoins.
/* Model.cto File:- */
namespace org.whiz.whizcoin
// ASSETS:-
abstract asset Currency{
o Double rate default=100.00
o Double coins
}
asset WhizCoin identified by currencyid extends Currency{
o String currencyid default = "WhizCoin"
//--> Member owner
}
// PARTICIPANTS:-
abstract participant user{
o String name
o Integer balance
}
participant Member identified by memberId extends user {
o String memberId
}
// Transactions:-
transaction distributeCoins {
--> Member receiver
o Double amount
-->Currency wc
}
/* logic.js File:- */
'use strict';
var NS = 'org.whiz.whizcoin';
/**
* #param {org.whiz.whizcoin.distributeCoins} distributeCoins - Distribute Coins
* #transaction
*/
function distributeCoins(distributeCoins) {
distributeCoins.receiver.balance += distributeCoins.amount;
distributeCoins.wc.coins -= distributeCoins.amount;
return getParticipantRegistry('org.whiz.whizcoin.Member')
.then(function (ParticipantRegistry) {
return ParticipantRegistry.update(distributeCoins.receiver);
})
.then(function() {
return getAssetRegistry('org.whiz.whizcoin.WhizCoin');
})
.then(function (AssetRegistry) {
return AssetRegistry.update(distributeCoins.whizcoin);
});
}
After submitting the transaction, the error I'm getting is:
Error: Expected a Resource or Concept.
I'm really stuck and couldn't find any solution anywhere else. Please help. Thanks in advance!

Answer 1

In the section of your logic where you are updating the Asset Registry you are using a variable that doesn't exist in the transaction, whizcoin. In your model file you use the name wc for this. Replacing AssetRegistry.update(distributeCoins.whizcoin) with AssetRegistry.update(distributeCoins.wc) should fix your issue.