How to estimate gasLimit of ERC20 contracts in web3.php project?

Question

I am using web3.php project in my Ethereum based project. A part of this project is sending ERC20 tokens, and in this regard, I need to estimate gas limit of transaction. For this purpose, I found the example below in the official documents of this project as below:

$contract->at($contractAddress)->estimateGas($functionName, $params, $callback);

and I changed it to my own code like this:

$gasLimit = 0;
$contract = new Contract($web3->provider, $contract_abi);
$contract->at($contract_address)->estimateGas('transfer', [
     'to'=>'0xa96Ce4C161271C797d979017821A278e1481eAfA',
     'value'=>1
   ], function ($err, $gas) use (&$gasLimit) {
         if ($err !== null) {
             echo $err->getMessage();
             return false;
         } else {
             $gasLimit = $gas;
         }
    }
);

After running this code, I receive this error:

PHP Fatal error:  Uncaught InvalidArgumentException: Please make sure you have put all function params and callback...

And I am not sure what are the required params in $params as the sample which is mentioned in this project. I tried to put something using documents provided for estimateGas() here.

May you help me please to solve this issue?

Answer 1

Try this example:

 $contract->at($contract_addr2)->estimateGas('transfer',
            $to_addr,
            1
        , function ($err, $gas) use (&$gasLimit) {
            if ($err !== null) {
                echo $err->getMessage();
                return false;
            } else {
                $gasLimit = $gas;
            }
        });