JS: Power Up Hive

Full, runnable src of Power Up Hive can be downloaded as part of: tutorials/javascript (or download just this tutorial: devportal-master-tutorials-javascript-24_power_up_hive.zip).

This tutorial runs on the main Hive blockchain. And accounts queried are real users with liquid HIVE balances.

Intro

This tutorial will show few functions such as querying account by name and getting account balance. We are using the call function provided by the dhive library to pull account from the Hive blockchain. A simple HTML interface is used to capture the account and its HIVE balance as well as allowing interactively power up part or all of HIVE to choose account.

Also see:

• transfer_to_vesting_operation

Steps

1. App setup Setup dhive to use the proper connection and network.
2. Search account Get account details after input has account name
3. Fill form Fill form with account reward balances
4. Power up Power up HIVE with Hive Signer or Client-side signing.

1. App setup

Below we have dhive pointing to the production network with the proper chainId, addressPrefix, and endpoint. There is a public/app.js file which holds the Javascript segment of this tutorial. In the first few lines we define the configured library and packages:

const dhive = require('@hiveio/dhive');
let opts = {};
//connect to production server
opts.addressPrefix = 'STM';
opts.chainId =
    'beeab0de00000000000000000000000000000000000000000000000000000000';
//connect to server which is connected to the network/production
const client = new dhive.Client('https://api.hive.blog');

2. Search account

After account name field is filled with some name, we do automatic search for account by name when input is focused out. HTML input forms can be found in the index.html file. The values are pulled from that screen with the below:

    const accSearch = document.getElementById('username').value;
    const _account = await client.database.call('get_accounts', [[accSearch]]);
    console.log(`_account:`, _account);

3. Fill form

After we fetched account data, we will fill form with HIVE balance and show current balance details.

const name = _account[0].name;
const hive_balance = _account[0].balance;
const balance = `Available Hive balance for ${name}: ${hive_balance}<br/>`;
document.getElementById('accBalance').innerHTML = balance;
document.getElementById('hive').value = hive_balance;
const receiver = document.getElementById('receiver').value;

4. Power up

We have 2 options on how to Power up. Hive Signer and Client-side signing options. By default we generate Hive Signer link to Power up (transfer to vesting), but you can use client signing option to Power up right inside tutorial, note client-side signing will require Active private key to perform operation.

In order to enable client signing, we will generate operation and also show Active Private key (wif) field to sign transaction right there client side. Below you can see example of operation and signing transaction, after successful operation broadcast result will be shown in user interface. It will be block number that transaction was included.

window.submitTx = async () => {
    const privateKey = dhive.PrivateKey.fromString(
        document.getElementById('wif').value
    );
    const op = [
        'transfer_to_vesting',
        {
            from: document.getElementById('username').value,
            to: document.getElementById('receiver').value,
            amount: document.getElementById('hive').value,
        },
    ];
    client.broadcast.sendOperations([op], privateKey).then(
        function(result) {
            document.getElementById('result').style.display = 'block';
            document.getElementById(
                'result'
            ).innerHTML = `<br/><p>Included in block: ${
                result.block_num
            }</p><br/><br/>`;
        },
        function(error) {
            console.error(error);
        }
    );
};

That’s it!

To run this tutorial

1. git clone https://gitlab.syncad.com/hive/devportal.git
2. cd devportal/tutorials/javascript/24_power_up_hive
3. npm i
4. npm run dev-server or npm run start
5. After a few moments, the server should be running at http://localhost:3000/