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DIA Wasm Oracle

Introduction​

DIA has a dedicated Wasm-based oracle. It can be universally deployed on any chain that supports substrate Wasm environment.

Prerequisites​

Make sure the version of ink you are on is v3.0.1.

Getting started​

To access values from DIA wasm oracles you need to copy the diadata directory to your contract so that you can access DIA structs, that contain the oracle data.

Contract Integration​

In your contract, create storage with DiaDataref, this is used to access values from the oracle.

    #[ink(storage)]
    pub struct OracleExample {
        diadata: DiadataRef,
        ....
        ....
    }

This struct can be used to access data from pub functions from the oracle contract.

To instantiate a contract's access to the oracle you need to pass the DIA oracle address, either using the constructor or by creating a separate write function to update with the value of oracle at a later stage.

Here is an example using a constructor:

    #[ink(constructor)]
    pub fn new(
        oracle_address: AccountId, 
    ) -> Self {
        let diadata: DiadataRef = ink_env::call::FromAccountId::from_account_id(oracle_address);  
        Self {
            diadata
        }
    }

Here, oracle_address refers to the DIA oracle address of a deployed oracle contract.

Access the value​

Next, to access an oracle value you can simple call the get() function:

 pub fn get(&self ) -> diadata::ValueTime {
            return self.diadata.get(String::from("ETH"));
        }

This returns the ETH price value time given by the oracle.

Config changes​

Make sure you add diadata/std in you config:

std = [
    "ink_metadata/std",
    "ink_env/std",
    "ink_storage/std",
    "ink_primitives/std",
    "scale/std",
    "scale-info/std",
    "diadata/std",
]

Addresses​

Astar Wasm Smart Contract: XmVR4FbKWLYQgyHVxkFiBYScVo662WgSCoS84uZZPWNrtRT Shibuya Wasm Smart Contract: X5NLwAUYX7FwVk25a8JwaXtuVJQsW87GQcKxYoF3aLyu8Pz

Learn more​

See the entire oracle code and instructions on how to run and oracle service by yourself in our github repo.