tronWeb.contract

Smart Contract Deployment

For deploying a smart contract, you can not only use the tronWeb.transactionBuilder.createSmartContract <createSmartContract> interface, but also the tronWeb.contract().new() <tronweb.contract().new> interface.

Smart Contract Invocation

Get smart contract instance

Before calling a smart contract, you need to obtain the smart contract instance first. You can create a contract instance in the following two ways:

//Example 1
let abi = [...];
let instance = await tronWeb.contract(abi,'contractAddress');

//Example 2
let instance = await tronWeb.contract.at('contractAddress');

Calling smart contract methods

Different types of contract methods need to be invoked by different tronweb apis:

Use call to execute pure or view smart contract methods, please refer to method.call() <contract.call()> Use send to execute non-pure or modify smart contract methods, please refer to method.send() <contract.send()> for specific usage instructions.

---

tronWeb.contract

Creates a contract object that wraps an ABI. Allows you to easily call functions on on the contract.

Usage

tronWeb.contract()

Parameters

abi:Optionally provide the ABI for a contract. address:Optionally provide the address for a contract. Hex or Base58 format

Returns

Object

Example

//example 1:Create the contract object through contract address and ABI
let instance = await tronWeb.contract([{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"}],"TREwN2qRkME9TyQUz8dG6HfjEyKGMPHAS5")

//example 2:First create an empty contract object, and then specify the contract address by at() function. If the abi is on the chain, at() function will load ABI automatically , else you need to load it manually
let instance = await tronWeb.contract().at("TREwN2qRkME9TyQUz8dG6HfjEyKGMPHAS5");

If the contract ABI does not exist on the chain, Please invoke loadAbi function to manually load the contract ABI. An example is as below:

//example 1
let instance =await tronWeb.contract([{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"}],"TREwN2qRkME9TyQUz8dG6HfjEyKGMPHAS5")
let res = await instance.totalSupply().call({_isConstant:true})

//example 2
let instance = await tronWeb.contract().at("TREwN2qRkME9TyQUz8dG6HfjEyKGMPHAS5");
instance.loadAbi([{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"}]);
let res = await instance.totalSupply().call({_isConstant:true})

tronweb.contract().new

Deploy a smart contract.

Usage

let abi = 'some abi for contract';
let code = 'bytecode';
async function deploy_contract(){
  let contract_instance = await tronWeb.contract().new({
    abi:JSON.parse(abi),
    bytecode:code,
    feeLimit:1000000000,
    callValue:0,
    userFeePercentage:1,
    originEnergyLimit:10000000,
    parameters:[para1,2,3,...]
  });
  console.log(contract_instance.address);
}

Parameters

Parameter	Description	Data Type	Option
abi	Smart Contract’s Application Binary Interface.	String	Required
bytecode	The compiled contract’s identifier, used to interact with the Virtual Machine.	String	Required
feeLimit	The maximum SUN consumes by deploying this contract. (1TRX = 1,000,000SUN)	Integer, long	Optional
allValue	Amount of SUN transferred to the contract with this transaction. (1TRX = 1,000,000 SUN)	Integer	Optional
userFeePercentage	The energy consumption percentage specified for the user calling this contract.	Integer between 0 and 100	Optional
originEnergyLimit	The max energy which will be consumed by the owner in the process of execution or creation of the contract, is an integer which should be greater than 0.	Integer	Optional
parameters	Parameter passed to the constructor of the contract.	Array	Optional, required if constructor needs parameters

Note

for the userFeePercentage parameter, it is strongly recommended to set the integer value between 1 and 99 (inclusive). Setting as 0 could potentially open the contract developer up to an infinite loop time-out attack.

Returns

Object

Example

let abi = 'some abi for contract';
let code = 'bytecode';
async function deploy_contract(){
  let contract_instance = await tronWeb.contract().new({
    abi:JSON.parse(abi),
    bytecode:code,
    feeLimit:1_00_000_000,
    callValue:0,
    userFeePercentage:1,
    originEnergyLimit:10_000_000
    //parameters:[para1,2,3,...]
  });
  console.log(contract_instance.address);
}

deploy_contract();// Execute the function
Promise { <pending> }
> 414d137bb7f91e8704d712d3967f6a745b9eedd839

---

Trigger a smart contract

After creating a contract instance, you can execute the contract’s methods.

Use call to execute a pure or view smart contract method.

Use send to execute a non-pure or modify smart contract method.

Please refer to call(), send().

There are two ways to create a contract instance:

//Example 1
let abi = [...];
let instance = await tronWeb.contract(abi,'contractAddress');

//Example 2
let instance = await tronWeb.contract.at('contractAddress');

---

call()

Use call to execute a pure or view smart contract method. These methods do not modify the blockchain, do not cost anything to execute and are also not broadcasted to the network.

Usage

//Example 1
let contract = await tronWeb.contract.at('contractAddress');
let result = await contract.function_name(para1,para2,...).call();

//Example 2
let contract = await tronWeb.contract.at('contractAddress');
let result = await contract["function_name"](para1,para2,...).call();

Parameters

No need to pass parameters

Returns

Object

Example

//Example 1
async function triggercontract(){
  let instance = await tronWeb.contract().at('TBBp5VF2q73hfMUoyxr138Kx3kbsi6HQRS');
  let res = await instance.totalSupply().call();
  console.log(res);
}
triggercontract();

//Example 2
async function triggercontract(){
  let instance = await tronWeb.contract().at('TBBp5VF2q73hfMUoyxr138Kx3kbsi6HQRS');
  let res = await instance["totalSupply"]().call();
  console.log(res);
}
triggercontract();

---

send()

Use send to execute a non-pure or modify smart contract method on a given smart contract that modify or change values on the blockchain. These methods consume resources(bandwidth and energy) to perform as the changes need to be broadcasted out to the network.

Usage

let contract = await tronWeb.contract.at('contractAddress');
let result = await contract.function_name(para1,para2,...).send({
    feeLimit:100_000_000,
    callValue:0,
  tokenId:1000036,
  tokenValue:100,
  shouldPollResponse:true
});

Parameters

Parameter	Description	Data Type
feeLimit	The maximum SUN consumes by calling this contract method. Hard capped at 10000 TRX. (1TRX = 1,000,000SUN)	Integer
callValue	Amount of TRX transferred with this transaction, measured in SUN (1 TRX = 1,000,000 SUN).	Integer
shouldPollResponse	If set to TRUE, this will wait until the transaction is confirmed on the solidity node before returning the result.	Boolean
tokenId	If the function accepts a trc 10 token , then the id of the same	String
tokenValue	Amount of token sent with the call.	Integer

Returns

Object

Example

async function triggercontract(){
    try {
        let instance = await tronWeb.contract().at('TQQg4EL8o1BSeKJY4MJ8TB8XK7xufxFBvK');
        let res = await instance.transfer('TWbcHNCYzqAGbrQteKnseKJdxfzBHyTfuh',500).send({
            feeLimit:100_000_000,
            callValue:0,
            shouldPollResponse:true
        });

        console.log(res);

    } catch (error) {
        console.log(error);
    }
}

triggercontract();

---