react ethersjs metamask with Custom RPC provider

Question

in my react app i want to use alchemy/someother-provider RPC and i want to use metamask as singer ( window.ethereum )

how to i set that ?

my current code :

var provider = new ethers.providers.JsonRpcProvider (RPCURL); var contract = new ethers.Contract(CONTRACT_ADDRESS, NEWABI, provider); var contractsinger = new ethers.Contract(CONTRACT_ADDRESS, NEWABI, provider);

after conecting to metamask the "contractsinger" becomes :

  var providerforsinger = new ethers.providers.Web3Provider(window.ethereum, "any"); 
   signer = providerforsinger.getSigner();
   contractsinger = new ethers.Contract(CONTRACT_ADDRESS, NEWABI, signer);

Answer 1

Here you can try this

const getProviderOrSigner = async (needSigner = false) => {
    
    const web3Provider = new providers.Web3Provider(provider);

    if (needSigner) {
      const signer = web3Provider.getSigner();
      return signer;
    }
    return web3Provider;
  };

Here needSigner will be true or false based on data

Moreover to call the function from smart contract

const signer = await getProviderOrSigner(true);
const Contract = new Contract(
        TOKEN_ADDRESS,
        abi,
        signer
      );
      
      const tx = await Contract.functionName();