contract methods undefined

Question

I am quite new with javascript web3 so don't be judge too hard.

I am using web3 version 1.0.0 beta.

I am taking the web3 reference this way:

if (typeof web3 !== 'undefined') {
    // If a web3 instance is already provided by Meta Mask.
    web3Provider = web3.currentProvider;
    web3 = new Web3(web3.currentProvider);
} else {
    // Specify default instance if no web3 instance provided
    web3Provider = new Web3.providers.HttpProvider('https://rinkeby.infura.io/v3/1b07b6c661304ef48005e16b43b7efa9');
    web3 = new Web3(web3Provider);
}

And then i am trying to get the contract reference:

var abi = [...];

console.log(abi);

var myContract = web3.eth.contract(abi, "0x2a2a7c53a6cc3d775e80c38d0fc446e73078902f");




myContract.methods.getPoll(1)
.call({from:localAccount}, function(error, result){
    console.log('error: ' + error);
    console.log(result);
})

The error is: Cannot read property 'getPoll' of undefined

Answer 1

You aren't creating the contract object correctly. What version of Web3.js are you using? 1.0 or 0.2.x? Here is how you do it for each:

1.0: var myContract = new web3.eth.Contract(abi, "0x2a2a7c53a6cc3d775e80c38d0fc446e73078902f")

0.2.x: var myContract = web3.eth.contract(abi).at("0x2a2a7c53a6cc3d775e80c38d0fc446e73078902f")

I highly suggest you use 1.0 if you aren't yet, even though it's in beta.

Answer 2

Change this:

web3.eth.contract

To this:

new web3.eth.Contract

Answer 3

You must write it in this form:

if getPoll method is view or pure:

myContract.methods.getPoll(1).call(option,function(error,result){
    if (! error)
        console.log(expand(result));
    else
        console.log(error);
});

and if the method is changing the state variables use send method, instead of call.

option is a variable that clarify the transaction specifications, like:

var option = {from: 0x...};