This tutorial is part of series that aims to demonstrate
how to use steem.js to build STEEM projects and bot with real work application.

• Tutorials - 1-10 - Building Bots with Steem.js
• #11 Running your Steem.js Bot 24/7 on a Server #11

The completed bot code is here - I know some people find it easier to see everything in one block and follow along that way. ⬅️

Outline

In this tutorial, we look at how to get the wallet data of a STEEM user. Particularly we’ll look at getting ’transfer’ data where usually the wallet also contains information about powering up/down and claiming rewards.

Difficulty

Beginner - This is a fairly friendly tutorial for those familiar with Steem-js and Javascript. Please re-visit tutorials 1-10 if you’re unsure of any aspects of this tutorial.

Learning Goals

• look at the getAccountHistory() steem.js library function
• display a list of the latest user wallet history

Preface

Before diving into the tutorial I thought I’d share how I decided to make this tutorial. I’ve been looking at adding new features to steem-js-boilerplate while working on personal steem platform based projects. I release I had not yet looked into where the wallet data is stored and how to retrieve it. in my doc search/googling I came across this GitHub issue How to get user wallet history? That had gone unanswered.

My initial attempt worked backwards through blocks one by one looking for a relevant user and incoming/outgoing ‘transfer’ type transactions. While this totally works it’s completely unreasonable for a web app and pretty slow for a bot style script taking roughly 5minutes to process 1hour of blocks.

I went in search of another way. Looking through the postpromoter bot code I found the function I needed. While not immediately obvious it makes sense after you know that getAccountHistory() gets all actions affecting a user over the blockchain, these can be filtered to show just votes/comments/transfers etc.

Intro/Setup

This tutorial is focussed around building the page in the browser and running the code on the front end but of course, there is no reason why this couldn’t be on the backend or as part of a separate micro-service.

I’ve created a starting template here a single html file with CDN links for bootstrap, Steem.js, jQuery and the basic html structure ready to go.

Getting Account/Wallet History

getAccountHistory function is listed in the docs but without any explanation, it’s not inherently clear exactly what this should be used for. In fact, this shows all actions that affected a user account and works great for what we need.

The function has 3 parameters and a callback function -

account - A single steem username

from - The first transactions you want. Works backwards in time from this number. E.g A value of 100 would get the users 100th, 99th, 98th etc. Use -1 to get latest

limit - The number of transactions to get. From 100 with limit 100 would get from 100 - 0. Accepts large numbers e.g 9999.

steem.api.getAccountHistory(account, from, limit, function(err, result) {
  console.log(err, result);
})

First, add data and the get account history to see it in actions. We’ll use 50 for ‘from’ and 50 for ‘limit’ to get the first 50 transactions on my account.

        const ACCOUNT_NAME = 'sambillingham'
        steem.api.getAccountHistory(ACCOUNT_NAME, 50, 50, (err, result) => {
          console.log(err, result)
        });

Check the console and you should notice the very first transactions contained in the array if your account creation. You might also notice that this function actually returns the block number along with the relevant data in op (operations) or virtual_op.

Moving on we’ll use -1 for ‘from’ and 50 for ‘limit’ to get the latest 50 transactions. We can use a simple filter to check each transaction for its type and store the relevant ones. Each transaction is an array where the first property is its own index and the second property is the data. We’ll first take the second property of the data e.g tx[1] where tx represents the transaction from there the data contains the block, op, op_in_trx, timestamp, trx_id, trx_in_block and virtual_op. we want to select the first property of the operation which is its type, leaving us with tx[1].op[0] and in this case, we’ll check it against transfer

        const ACCOUNT_NAME = 'sambillingham'
        const WALLET_FILTER = 'transfer'
        steem.api.getAccountHistory(ACCOUNT_NAME, -1, 50, (err, result) => {
          let transfers = result.filter( tx => tx[1].op[0] === WALLET_FILTER )
          console.log(transfers)
        });

You may see significantly less transfers in the console. Remember while we retrieve 50 transactions on our account many of those may be votes/comments/posts etc so after the filter you may need to increase you limit property.

Displaying latest wallet transactions

The console is great but with a couple more lines we can have it in the browser in a more realistic environment. A basic bootstrap table is already added to the html. We’ll loop over the transactions and add the individual data as a new row.

        const ACCOUNT_NAME = 'sambillingham'
        const WALLET_FILTER = 'transfer'
        steem.api.getAccountHistory(ACCOUNT_NAME, -1, 50, (err, result) => {
          let transfers = result.filter( tx => tx[1].op[0] === WALLET_FILTER )
          displayTransactions(transfers)
        });
        function displayTransactions(transactions){
          transactions.forEach((tx) => {
            let transfer = tx[1].op[1]
            let template =
            `<tr>
              <td>${transfer.from}</td>
              <td>${transfer.to}</td>
              <td>${transfer.amount}</td>
              <td>${transfer.memo}</td>
            </tr>`
            $('tbody').prepend(template)
          });
        }

The wallet page of steemit.com includes other types of transactions too. If you’re attempting to replicate that type of interface you’ll also need to filter for power up/down and claiming rewards.

The final code for this project can be found here

Let me know if you found this useful for any of your projects. Check out the previous tutorials

• [1-10] - Building Bots with Steem-js
• [#11] - Running your Steem.js Bot 24/7 on a Server #11

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Posted on Utopian.io - Rewarding Open Source Contributors

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