You spent a lot of time networking on Steemit, commenting, upvoting and trying to create your own little community. At the end of the day, you got a few hundreds (of thousands) followers. Nice.

But how many of your readers are actually supporting you too? In other words, what's the _engagement rate_ between the total number of your followers and the total _votes_ you get on your posts?

In today's tutorial we're going to write a short snippet using `php-steem-tools` and a little magic to get exactly that. I will describe the same approach used in the "Social Insights" section of [steem.supply](http://steem.supply), which generates the following chart:
***
![Screen Shot 2018-01-03 at 9.12.47 AM.png](https://res.cloudinary.com/hpiynhbhq/image/upload/v1514963595/ef0tgknljun1rjhsi2zc.png)
***

# Prerequisites

You will need basic understanding of PHP and composer.

# Step 1:  Add `php-steem-tools` to `composer.php`

Install composer (this is out of the scope of this tutorial, but if you need a good start, the [Composer website](http://getcomposer.org/) has a very good documentation). Open composer.php and add the following lines:
```
{
    "minimum-stability" : "dev",
    "require": {
        "dragos-roua/php-steem-tools": "v0.0.4-alpha"
    }
}
```
The current version of the package is 0.0.4-alpha, and you need the "minimum-stability" setting to be at the "dev" level.

# Step 2: Require the package and instantiate the Steem API
Create a file (in the same folder as composer.php) and require the package:

```require __DIR__ . '/vendor/autoload.php';```

Now you'll have access to all the classes you included in the composer.php file. Let's instantiate the API. Add the following lines:
```
$config['webservice_url'] = 'steemd.minnowsupportproject.org';
$api = new DragosRoua\PHPSteemTools\SteemApi($config);
```
Now, the `$api` variable will contain a new API object which will query the data from the `webservice_url` address. If you want to query a different node, just change this address.

# Step 3: Pick an author and get the total number of the followers

If you read my [previous php-steem-tools tutorial](https://steemit.com/utopian-io/@dragosroua/how-to-get-the-payment-rewards-of-a-steemit-user-in-less-than-50-lines), you noticed that the first two steps are pretty much identical. Here's wehre we change things a bit.

We are going to find the total number of followers of the author. This is a recursive call, hence resource intensive, so we're going to use a little folder-based cache.

Here's the code:
```
$follower_count  = $api->getFollowerCount($account);
$returned_follower_count = $follower_count['followers'];
$cache_folder = "./";
$file_name = $cache_folder.$author.".txt";
$cache_interval = 86400; // seconds for the cache file to live
if(file_exists($file_name)){
	
	// if the file was modified less than $cache_interval, we do nothing
	
	$current_time = time();
	if($current_time - filemtime($file_name) > $cache_interval){
		$follower_count  = $api->getFollowerCount($author);
		// write to the file again
		$handle = fopen($file_name, 'w+') or die('Cannot open file:  '.$file_name);
		fwrite($handle, "followers|".$follower_count);
		fclose($handle);
		$returned_follower_count = $follower_count;
	}
	else {
		// get the data from the cache file
		$cache_contents = file($file_name);
		$first_line = $cache_contents[0];
		$content = explode("|", $first_line);
		$returned_follower_count = $content[1];
	}
}
else {
	$follower_count  = $api->getFollowerCount($author);
	// write the data to cache file
	$handle = fopen($file_name, 'w+') or die('Cannot open file:  '.$file_name);
	fwrite($handle, "followers|".$follower_count);
	fclose($handle);
	$returned_follower_count = $follower_count;
}
```
It's pretty much self-explanatory, not much going on here. We make a call to the `getFollowerCount()` of the API and save the result in txt file. The variable `$follower_count` will hold the returned value from the API call.

# Step 4: Get the total number of posts and the votes

The total number of posts is not really required for our goal, but it's a nice addition. Again, if you looked at my previous tutorial, you'll notice some similarities.

What we are going to do is to call the `getDiscussionsByAuthorBeforeDate($params, $transport)`  function of the API, which will return the total number of posts during the last 8 days. If we have a result, we then cycle through the returned JSON object and the following:
* increment the value of the variable `$total_posts`
* add to the array `$votes_number` the voter nickname as key, and total number of his votes as the value, because we are going to use the total number of users who are actually voting
* at the end of the loop, we just print the calculated ratio

Here's the code:
```
date_default_timezone_set('UTC');
$dateNow = (new \DateTime())->format('Y-m-d\TH:i:s'); 
$date_8days_ago = date('Y-m-d\TH:i:s', strtotime('-8 days', strtotime($dateNow)));
$params = [$author, '', $date_8days_ago, 100];
$remote_content = $api->getDiscussionsByAuthorBeforeDate($params, 'websocket');	
//print_r($remote_content);
if(isset($remote_content)){
	if (array_key_exists('error', $remote_content)){
		echo "Something is not ok. You should investigate more.\n";
	}
	else 
	{
		$votes_number = array();
		$total_posts = 0;
		
		foreach($remote_content as $rkey => $rvalue){
			
			if($rvalue['pending_payout_value'] !== '0.000 SBD' && $rvalue['max_accepted_payout'] != 0){
				
				foreach($rvalue['active_votes'] as $idx => $voter){
					$voter_nickname = $voter['voter'];
					
					if($voter_nickname != $author){
						
						if(array_key_exists($voter['voter'], $votes_number)){
							
							$votes_number[$voter['voter']] += 1;
						} 
						else {
							
							$votes_number[$voter['voter']] = 1;
						}
					}
				}
			}
			$total_posts++;
		}
		echo "\n**************\n";
		echo "Total number of posts during the last 7 days: ".$total_posts."\n";
		echo "Total number of voters: ".count($votes_number)." \n";
		echo "Total followers: ".$returned_follower_count."\n";
		
		echo "**************\n";
		echo "Conversion rate: ".number_format((count($votes_number) * 100)/$returned_follower_count, 2)."%\n**************\n";
	}
}
```
That's pretty much it!

Now you can invoke the script (in the same folder) by issuing this command: `php conversionRate.php`.

And here's how it looks for the author `utopian-io`:
***
![Screen Shot 2018-01-03 at 9.00.44 AM.png](https://res.cloudinary.com/hpiynhbhq/image/upload/v1514964710/kfzifmqyzqzictiprczi.png)
***
`utopian-io` has a 10.69% engagement rate.

You can get the full source of this tutorial from the 'examples' folder of the [php-steem-tools repository](https://github.com/dragosroua/php-steem-tools) on GitHub.

_Note: this snippet is calculating the ratio between your followers and the number of votes you get, resulting in an overview of your popularity. It doesn't calculate how many of your followers are voting you. I leave this as a homework for you. Hint: there is a function in the api called `getFollowers($account, $transport)`, which returns an array. You may want to intersect that array with the `$votes_number` array created in the script above, and get the percentage of the voting followers._
***
_I'm a serial entrepreneur, blogger and ultrarunner. You can find me mainly on my blog at [Dragos Roua](http://dragosroua.com) where I write about productivity, business, relationships and running. Here on Steemit you may stay updated by following me @dragosroua._
<center>
![Dragos Roua](http://dragosroua.com/wp-content/uploads/2014/05/bamf-e1448824881306.png)</center>
_If you're new to Steemit, you may find these articles relevant (that's also part of my witness activity to support new members of the platform)_:
* [Rewards: Were Does The Money Come From?](https://steemit.com/steemit/@dragosroua/steemit-newbie-faq-rewards-were-does-the-money-come-from)
* [Netiquette: How To Avoid Being A Steem Douche?](https://steemit.com/steem/@dragosroua/steemit-newbie-faq-netiquette-how-to-avoid-being-a-steem-douche)
* [Witnesses: What Are They And Why Should You Care?](https://steemit.com/steemit/@dragosroua/steemit-newbie-faq-witnesses-what-are-they-and-why-should-you-care)
* [How Can I Mine Steem And What CPU / GPU Power Do I Need For That?](https://steemit.com/steemit/@dragosroua/steemit-newbie-faq-how-can-i-mine-steem-and-what-cpu-gpu-power-do-i-need-for-that)
* [The Beginner Guide To Not Getting Hacked On Steemit](https://steemit.com/steemit/@dragosroua/the-beginner-guide-to-not-getting-hacked-on-steemit)

<br /><hr/><em>Posted on <a href="https://utopian.io/utopian-io/@dragosroua/how-to-calculate-your-engagement-rate-using-php-steem-tools">Utopian.io -  Rewarding Open Source Contributors</a></em><hr/>