Interacting with Deployed Contract

Now, you are ready to interact with the contract that you have deployed. Go back to MyEtherWallet desktop and click on the “Interact with Contract” tab as shown in the screenshot below −

Interact With Contract

Paste the contract address that you previously copied in the “Contract Address” field. You also need to paste the “ABI / JSON Interface” of the contract on the above screen.

To get the ABI, go to the Remix window and click on the ABI button as shown in the screenshot below.

ABI button

The ABI / JSON interface will be copied to the clipboard. Paste this in your favorite editor to examine the generated interface, which is shown below −ABI / JSON Interface [ { “constant”: false, “inputs”: [ { “name”: “newDeposit”, “type”: “uint256” } ], “name”: “send”, “outputs”: [], “payable”: false, “stateMutability”: “nonpayable”, “type”: “function” }, { “inputs”: [ { “name”: “initialAmount”, “type”: “uint256” }, { “name”: “initialValue”, “type”: “uint256” } ], “payable”: false, “stateMutability”: “nonpayable”, “type”: “constructor” }, { “constant”: true, “inputs”: [], “name”: “getAmount”, “outputs”: [ { “name”: “”, “type”: “uint256” } ], “payable”: false, “stateMutability”: “view”, “type”: “function” }, { “constant”: true, “inputs”: [], “name”: “getBalance”, “outputs”: [ { “name”: “”, “type”: “uint256” } ], “payable”: false, “stateMutability”: “view”, “type”: “function” } ]

After you paste this JSON in the MyEtherWallet interface, you will notice that the ACCESS button below the JSON interface is now activated, as shown below −

My Ether Wallet

Click Access button to access the contract.

Upon clicking the Access button, the contract address and function selection dropdown will appear on the screen like in the Remix editor. This is shown in the screenshot below −

Access button

You may check the various functions of the contract as in the case of Remix deployment. Note that the contact is now deployed on an external Ganache Blockchain. Check the getAmount function; you will get the Amount value of zero and the getBalance will show a balance of 1000.

Now try sending some money. It will present you a textedit control for entering the amount. When you write the contract, some “gas” would be used and you will be asked to confirm the transaction before writing it to the Blockchain. The transaction would be executed in a short while depending on the mining timing set by you on the Ganache server. After this, you can reexamine the value and the amount fields of the contract to verify that these are indeed modified.

You may now examine the Ganache desktop to view the transactions that you have performed so far. A sample output is shown below −

sample output

So far, you were both the contract creator and the contract executor. This does not make much sense, as you expect others to use your contract. For this, we will create another client for our Ganache Blockchain and send some money from the newly created account # 2 to the contract creator at account # 1.

Similar Posts

  • Creating Contract Users

    In this chapter, we will learn the creation of contract users on Ethereum. To create a user for our published contract, we will create another MyEtherWallet client attached to the same Ganache Blockchain that you have been using in the previous steps. Go to the MyEtherWallet screen and create a new wallet. Click on the contracts menu and select the “Interact with…

  • Deploying the Contract

    In this chapter, we will learn how to deploy contract on Ethereum. Click on the Run menu option to deploy the contract. The following screen will appear. The contract name is shown in the highlighted list box. Below this, you will notice the Deploy button, click on it to deploy the contract. The contract will be deployed…

  • Introduction

    A huge success of Bitcoin raised interest in the minds of several to create their own currencies. Looking at the advantages offered by Bitcoin – a digital currency, people wanted to use the concept of Blockchain in their own applications. People wanted to move out of their physical contracts to smart digital contracts where several…

  • MyEtherWallet

    For client application, you will use MyEtherWallet. Download MyEtherWallet software from the following URL − If required, unzip the downloaded file and open index.html. You will see the following interface for creating a new wallet.

  • Ganache for Blockchain

    Ganache is used for setting up a personal Ethereum Blockchain for testing your Solidity contracts. It provides more features when compared to Remix. You will learn about the features when you work out with Ganache. Before you begin using Ganache, you must first download and install the Blockchain on your local machine. Downloading Ganache You…

  • Solidity for Contract Writing

    Solidity is an object-oriented language especially developed for contract writing. It is a high-level language, which inherits traits from C++, Python, and JavaScript. The Solidity compiler compiles your source code into bytecode that runs on Ethereum Virtual Machine (EVM). For quick understanding of the Solidity syntax, look at the sample code in the IDE.pragma solidity…