Getting more call metadata from a generic call

Question

I'm trying to build a somewhat generic, somewhat specific call dispatcher that allows me to inspect metadata about the call in order to constrain it by either

• call index / pallet index
• call name / pallet name

Here is an example trait implemented in my trait Config

/// Proposed dispatchable call
type Proposal: Parameter
    + Dispatchable<Origin = Self::Origin>
    + EncodeLike
    + Decode
    + GetDispatchInfo;

I'm aware of the traits GetCallName and GetCallMetadata but they don't seem to be implemented on a generic Call instantiated at the runtime level. For clarity, my runtime implementation is

impl Config for Test {
    ...
    type Proposal = Call;
}

I don't want to allow just any call to be processed in some functions. My intention is to do something like:

ensure!(call.get_call_metadata().function_name() === "hardcoded_function_name")

or

ensure!(valid_calls.contains(call.get_call_metadata().function_name()))

Is there an easy or thoughtful way to approach this in Substrate-style that allows me to keep generality. For example, it would be interesting if the call was filterable somehow so that 10 calls were allowed and I can define these at runtime (I had tried to add a tuple and implement a trait for tuples but it seemed too hacky).

Answer 1

You can filter the call in runtime. Here is how proxy do:

Provide a filter configuration here https://github.com/paritytech/substrate/blob/master/frame/proxy/src/lib.rs#L124-L134.

Configure it here https://github.com/paritytech/substrate/blob/master/bin/node/runtime/src/lib.rs#L264-L319.