CODEWITHSUNDEEP
corda
Rudrakshi
Rudrakshi

Reputation: 55

Corda: Creating contracts dynamically

In our use case, we need to define certain rules at run-time based on which a node will transact with other nodes in the network. For example, we want to define a rate at the front end and check that the transaction is happening with this rate only for that particular node. In other words, can we define the terms and conditions at run-time and would this still be called a smart contract or does a smart contract need to be always hard-coded. Is there any alternate way to look at this?

Upvotes: 1

Views: 322

Answers (2)

Richard Green
Richard Green

Reputation: 2062

To extend Joel's comment, the contract is indeed hard-coded, but there's nothing wrong with putting meta logic in there as long as the code runs the same way every time (i.e. it's deterministic).

What do I mean by this? Well, you can put a String type in your state which contains an expression that can then be evaluated (if you refer to https://relayto.com/r3/FIjS0Jfy/VB8epyay73 you can see the inclusion of a very basic maths expression used in a smart contract). There's nothing wrong with making this String as complex as possible, but just be aware that any potential users of your application will start raising eyebrows if you remove a lot of the protection that Corda offers of validation if you start dumbing down the coded verification logic and putting it all into a String.

Upvotes: 1

Joel
Joel

Reputation: 23210

The contract itself is hard-coded. This is because every node needs to agree that a given transaction is valid according to the contract rules, forever. If they varied based on the node, some nodes would consider a transaction valid while another would consider the transaction invalid, leading to inconsistencies in their ledgers.

Instead, you'd have to impose this logic in the flow. Let's say you have a TradeOffer flow that proposes a trade. Each node could install their own response flow that is initiated by TradeOffer flow. Each node's response flow could impose different conditions. For example, one node might sign any transaction, while another one would check that the proposed rate is within specified bounds.

Upvotes: 1

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