Running transactions

The Run tab is an important section of Remix. It allows you to send transactions to the current environment.

image

Run Setup

The following settings allow you to directly influence the transaction execution:

Environment:

  • JavaScript VM: All the transactions will be executed in a sandbox blockchain in the browser. This means nothing will be persisted and a page reload will restart a new blockchain from scratch, the old one will not be saved.
  • Injected Provider: Remix will connect to an injected web3 provider. Mist and Metamask are example of providers that inject web3, thus can be used with this option.
  • Web3 Provider: Remix will connect to a remote node. You will need to provide the URL address to the selected provider: geth, parity or any Ethereum client.
  • Account: the list of accounts associated with the current environment (and their associated balances).
  • Gas Limit: the maximum amount of gas that can be set for all the transactions created in Remix.
  • Value: the amount of value for the next created transaction (this value is always reset to 0 after each transaction execution).

image

Initiate Instance

This section contains the list of compiled contracts and 2 actions:

  • At Address assumes the given address is an instance of the selected contract. It is then possible to interact with an already deployed contract. There’s no check at this point, so be careful when using this feature, and be sure you trust the contract at that address.
  • Create send a transaction that deploys the selected contract. When the transaction is mined, the newly created instance will be added (this might take several seconds). Note that if the constructor has parameters, you need to specify them.

Pending Instances

Validating a transaction take several seconds. During this time, the GUI shows it in a pending mode. When transaction is mined the number of pending transactions is updated and the transaction is added to the log (see ../terminal)

Using the ABI

Using Deploy or At Address is a classic use case of Remix. It is possible though to interact with a contract by using its ABI. The ABI is a JSON array which describe its interface.

To interact with a contract using the ABI, create a new file in Remix with extension *.abi and copy the ABI content to it. Then in the input next to At Address, put the Address of the contract you want to interact with. Click on At Address, a new “connection” with the contract will popup below.

Using the Recorder

The Recorder allows to save a bunch of transactions in a JSON file and rerun them later either in the same environment or in another.

Saving to JSON allows to easily check the transaction list, tweak input parameters, change linked library, etc…

We can find many use cases for the recorder, for instance: : - After having coded and tested contracts in a constrained environment (like the JavaScript VM), it could be interesting to redeploy them easily in a more persisted environment (like a Geth node) in order to check whether everything behaves normally in a classic environment. - Deploying contract does often require more than creating one transaction. - Working in a dev environment does often require to setup the state in a first place.

image

Saving a record ends up with the creation of this type of content (see below):

In that specific record, 3 transactions are executed:

The first corresponds to the deployment of the lib testLib.

The second corresponds to the deployment of the contract test, the first parameter of the constructor is set to 11. That contract depends on a library. The linkage is done using the property linkReferences. In that case we use the addres of the previously created library : created{1512830014773}. the number is the id (timestamp) of the transaction that leads to the creation of the library.

The third parameter corresponds to the call to the function set of the contract test (the property to is set to: created{1512830015080}) . Input parameters are 1 and 0xca35b7d915458ef540ade6068dfe2f44e8fa733c

all these transactions are created using the value of the accounts account{0}.

{
"accounts": {
    "account{0}": "0xca35b7d915458ef540ade6068dfe2f44e8fa733c"
},
"linkReferences": {
    "testLib": "created{1512830014773}"
},
"transactions": [
    {
    "timestamp": 1512830014773,
    "record": {
        "value": "0",
        "parameters": [],
        "abi": "0xbc36789e7a1e281436464229828f817d6612f7b477d66591ff96a9e064bcc98a",
        "contractName": "testLib",
        "bytecode": "60606040523415600e57600080fd5b60968061001c6000396000f300606060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff1680636d4ce63c146044575b600080fd5b604a6060565b6040518082815260200191505060405180910390f35b6000610d809050905600a165627a7a7230582022d123b15248b8176151f8d45c2dc132063bcc9bb8d5cd652aea7efae362c8050029",
        "linkReferences": {},
        "type": "constructor",
        "from": "account{0}"
    }
    },
    {
    "timestamp": 1512830015080,
    "record": {
        "value": "100",
        "parameters": [
        11
        ],
        "abi": "0xc41589e7559804ea4a2080dad19d876a024ccb05117835447d72ce08c1d020ec",
        "contractName": "test",
        "bytecode": "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__browser/ballot.sol:testLib____________636d4ce63c6000604051602001526040518163ffffffff167c010000000000000000000000000000000000000000000000000000000002815260040160206040518083038186803b151561022e57600080fd5b6102c65a03f4151561023f57600080fd5b505050604051805190509050905600a165627a7a72305820e0b2510bb2890a0334bfe5613d96db3e72442e63b514cdeaee8fc2c6bbd19d3a0029",
        "linkReferences": {
        "browser/ballot.sol": {
            "testLib": [
            {
                "length": 20,
                "start": 511
            }
            ]
        }
        },
        "name": "",
        "type": "constructor",
        "from": "account{0}"
    }
    },
    {
    "timestamp": 1512830034180,
    "record": {
        "value": "1000000000000000000",
        "parameters": [
        1,
        "0xca35b7d915458ef540ade6068dfe2f44e8fa733c"
        ],
        "to": "created{1512830015080}",
        "abi": "0xc41589e7559804ea4a2080dad19d876a024ccb05117835447d72ce08c1d020ec",
        "name": "set",
        "type": "function",
        "from": "account{0}"
    }
    }
],
"abis": {
    "0xbc36789e7a1e281436464229828f817d6612f7b477d66591ff96a9e064bcc98a": [
    {
        "constant": true,
        "inputs": [],
        "name": "get",
        "outputs": [
        {
            "name": "",
            "type": "uint256"
        }
        ],
        "payable": false,
        "stateMutability": "view",
        "type": "function"
    }
    ],
    "0xc41589e7559804ea4a2080dad19d876a024ccb05117835447d72ce08c1d020ec": [
    {
        "constant": true,
        "inputs": [],
        "name": "getInt",
        "outputs": [
        {
            "name": "",
            "type": "uint256"
        }
        ],
        "payable": false,
        "stateMutability": "view",
        "type": "function"
    },
    {
        "constant": true,
        "inputs": [],
        "name": "getFromLib",
        "outputs": [
        {
            "name": "",
            "type": "uint256"
        }
        ],
        "payable": false,
        "stateMutability": "view",
        "type": "function"
    },
    {
        "constant": true,
        "inputs": [],
        "name": "getAddress",
        "outputs": [
        {
            "name": "",
            "type": "address"
        }
        ],
        "payable": false,
        "stateMutability": "view",
        "type": "function"
    },
    {
        "constant": false,
        "inputs": [
        {
            "name": "_t",
            "type": "uint256"
        },
        {
            "name": "_add",
            "type": "address"
        }
        ],
        "name": "set",
        "outputs": [],
        "payable": true,
        "stateMutability": "payable",
        "type": "function"
    },
    {
        "inputs": [
        {
            "name": "_r",
            "type": "uint256"
        }
        ],
        "payable": true,
        "stateMutability": "payable",
        "type": "constructor"
    }
    ]
}
}