README.md

Instruction to use this cross-contract calling smart contract

Contract Trapped During Exucution error while cross-contract calling issue

1. Build app & app2 smart contract using the following command:

   • cargo contract build --release

2. Upload .contract file of app1 and after thatn app2 to blockchain network either https://contracts-ui.substrate.io/ or https://polkadotjs-apps.web.app/#/contracts

3. If you upload app2 smart contract with the following constructor code, then while calling app_flip function from app2 contract cause issue which is listed below:

    #[ink(constructor)]
    pub fn new(init_value: bool, app_ref: AppRef) -> Self {
   
        Self {
            value: init_value,
            app: app_ref,
        }
    }
   

4. To call app_flip successfully from app2, uncomment the following code in app2 smart contract, then it works as follows:

   #[ink(constructor)]
   pub fn new(init_value: bool, app_code_hash: Hash, version: u32) -> Self {
       let total_balance = Self::env().balance();
       let salt = version.to_le_bytes();
       let app = AppRef::new(init_value)
           .endowment(total_balance / 4)
           .code_hash(app_code_hash)
           .salt_bytes(salt)
           .instantiate();
   
       Self {
           value: init_value,
           app: app.unwrap(),
       }
   }