Cross Contract Calling

Assume that the following contract A already exists on the chain.

@contractclass Libadd {  constructor() {}
  @constructor  default(): void {}
  @message(mutates = false)  add(a: i32, b: i32): i32 {    return a + b;  }}

If you want to call the contract in contract B, you can declare a @dynamic class to describe its interface.

@dynamicexport class Libadd {  // Note that the method experience here will be covered by the actual code, this writing is mainly for compiling  add(a: i32, b: i32): i32 {    return 0;  }}
@contractclass LibaddCaller {  constructor() {}
  @constructor  default(): void {}
  @message(mutates = false)  callAddFromExternal(outAddress: AccountId, a: i32, b: i32): i32 {    let outContract = new Libadd(outAddress);    let val = outContract.add(a, b);    return val;  }}

outAddress here is the instance address of contract Libadd.

This function can also call contracts written in other smart contract languages, such as ink!, as long as it follows the compatible metadata.json specification.