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Contract provider

When interacting with smart contracts in Unity, the provider is similar to a JavaScript provider. The provider is responsible for sending the request formed inside the contract proxy class to the blockchain RPC node and optionally decoding the response. If the provider doesn't decode the response, then it's considered an ILegacyProvider.

IProvider​

The IProvider interface defines the following function:

Task<TR> Request<TR>(string method, object[] parameters = null);

This function must send a JSON-RPC request with the given method and parameters. It must decode the JSON-RPC result response into the type TR.

The IProvider must also define two additional properties:

// The current chain ID the provider is connected to.
long ChainId { get; }

// The current address connected to the provider.
string ConnectedAddress { get; }

For backwards compatibility, the ILegacyProvider function is also defined:

object Request(string method, object[] parameters = null);

To easily support this function, use Request<object>:

public object Request(string method, object[] parameters = null)
{
  return this.Request<object>(method, parameters);
}

ILegacyProvider​

The ILegacyProvider is an interface that declares an interface that does not support response decoding. The ILegacyProvider interface defines the following function:

object Request(string method, object[] parameters = null);

This function must send a JSON-RPC request with the given method and parameters. It should decode the response, but it's not required. It may return any of the following:

  • The response as a JSON string
  • The response as a JSON string, wrapped in a Task
  • The response decoded into some object
  • The response decoded into some object, wrapped in a Task

If the function returns a JSON string, then the Contract class attempts to deserialize the JSON string into the desired type. If it returns any other object type, the Contract class attempts to convert to the desired type by first serializing the object into JSON, then deserializing the JSON back into the desired type. The desired type is defined in the contract interface used.

The ILegacyProvider must also define two additional properties:

// The current chain ID the provider is connected to.
long ChainId { get; }

// The current address connected to the provider.
string ConnectedAddress { get; }