Witnet basic RNG example

witnet-dummy-rng-example.sol

// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.9.0;

import "witnet-solidity-bridge/contracts/interfaces/IWitnetRNG.sol";

contract MyContract {

    uint32 public randomness;
    uint256 public latestRandomizingBlock;
    IWitnetRNG witnet;
    
    constructor () {
        witnet = IWitnetRNG(address("<address of the WitnetRNG contract>"));
    }

    function getRandomNumber() external payable {
        latestRandomizingBlock = block.number;
        witnet.randomize();
    }
    
    function fulfillRandomness() external {
        assert(latestRandomizingBlock > 0);
        randomness = witnet.random(type(uint32).max + 1, 0, latestRandomizingBlock);
    }
    
}