Trait ink_lang::reflect::ContractConstructorDecoder

source · [−]
pub trait ContractConstructorDecoder {
    type Type: DecodeDispatch + ExecuteDispatchable;
}
Expand description

Generated type used to decode all dispatchable ink! constructors of the ink! smart contract.

Note

The decoder follows the ink! calling ABI where all ink! constructor calls start with 4 bytes dedicated to the ink! constructor selector followed by the SCALE encoded parameters.

Usage

use ink_lang as ink;

#[ink::contract]
pub mod contract {
    #[ink(storage)]
    pub struct Contract {}

    impl Contract {
        #[ink(constructor)]
        pub fn constructor1() -> Self { Self {} }

        #[ink(constructor)]
        pub fn constructor2(input1: bool, input2: i32) -> Self { Self {} }

        #[ink(message)]
        pub fn message(&self) {}
    }
}

use contract::Contract;

fn main() {
    // Call to `constructor1` without input parameters.
    {
        let mut input_bytes = Vec::new();
        input_bytes.extend(selector_bytes!("constructor1"));
        assert!(
            <<Contract as ContractConstructorDecoder>::Type as Decode>::decode(
                &mut &input_bytes[..]).is_ok()
        );
    }
    // Call to `constructor2` with 2 parameters.
    {
        let mut input_bytes = Vec::new();
        input_bytes.extend(selector_bytes!("constructor2"));
        input_bytes.extend(true.encode());
        input_bytes.extend(42i32.encode());
        assert!(
            <<Contract as ContractConstructorDecoder>::Type as Decode>::decode(
                &mut &input_bytes[..]).is_ok()
        );
    }
    // Call with invalid ink! constructor selector.
    {
        let mut input_bytes = Vec::new();
        input_bytes.extend(selector_bytes!("non_existing_constructor"));
        assert!(
            <<Contract as ContractConstructorDecoder>::Type as Decode>::decode(
                &mut &input_bytes[..]).is_err()
        );
    }
    // Call with invalid ink! constructor parameters.
    {
        let mut input_bytes = Vec::new();
        input_bytes.extend(selector_bytes!("constructor2"));
        assert!(
            <<Contract as ContractConstructorDecoder>::Type as Decode>::decode(
                &mut &input_bytes[..]).is_err()
        );
    }
}

Required Associated Types

The ink! smart contract constructor decoder type.

Implementors