Custom PHP HTML Parser

<!DOCTYPE html>
<html>
<head>
    <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto">
    <style>
        body {
            font-family: Roboto;
        }

table {
            font-family: arial, sans-serif;
            border-collapse: collapse;
            width: 100%;
        }

td,
        th {
            border: 1px solid #dddddd;
            text-align: left;
            padding: 8px;
        }

tr:nth-child(even) {
            background-color: #dddddd;
        }

.card {
            box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
            transition: 0.3s;
            float: left;
            margin-left: 10px;
            margin-bottom: 20px;
            width: 40%;
        }

.card:hover {
            box-shadow: 0 8px 16px 0 rgba(0, 0, 0, 0.2);
        }

.container {
            padding: 2px 16px;
        }
    </style>
</head>
<body>

<h2>Welcome {user.name}</h2>

<table>
        <tr>
            <th>Client</th>
            <th>Name</th>
            <th>Balance</th>
        </tr>
        <%=list dataset="clients"
            <tr class="class" id="1234">
                <td align="left">{client.id}</td>
                <td>{client.name}</td>
                <td>R{client.balance}</td>
            </tr>
        =%>
    </table>
    
    <h2>List of Clients with Balances > 0</h2>
    
    <table>
        <tr>
            <th>Client</th>
            <th>Name</th>
            <th>Balance</th>
        </tr>
        <%=list dataset="clients"
             
        =%>
    </table>

<div style="margin-top: 10px;">
        <h2>Products</h2>
        
        <ul>
            <%=list dataset="products"
            <li>{products.name} {products.desc}</li>
            =%>
        </ul>
    </div>

<div style=""></div>
        <h2>Populate users using 'list dataset'</h2>

<%=list dataset="users"
            <div class="card">
                <div class="container">
                <h4><b>{u.name}</b></h4> 
                <p>{u.role}</p> 
                </div>
            </div>
        =%>
    </div>

<div style="margin-top: 20%;">
        <h2 >Populate users using dataset.map()</h2>

<%=dataset.map("users")
            <div class="card">
                <div class="container">
                <h4><b>{u.name}</b></h4> 
                <p>{u.role}</p> 
                </div>
            </div>
        =%>
    </div>

<div style="margin-top: 20%;">
        <h2 >Populate users using foreach()</h2>

<%=foreach("users")
            <div class="card">
                <div class="container">
                <h4><b>{u.name}</b></h4> 
                <p>{u.role}</p> 
                </div>
            </div>
        =%>
    </div>

<div style="margin-top: 20%;">
        <h2 >Populate users using for()</h2>

<%=for("users")
            <div class="card">
                <div class="container">
                <h4><b>{u.name}</b></h4> 
                <p>{u.role}</p> 
                </div>
            </div>
        =%>
    </div>
</body>
</html>

<?php
    /* 
        Online Custom PHP HTML Parser Compiler (Interpreter) and Editor 
        This Compiler already uses the HTMLParser package, require ('HTMLParser/HTMLParser.php') is not required
    */

/* build your own dataset and play around to see how HTMLParser works */
    $data = array 
        (
            '{user.name}' => 'Yung Cet',
            '{products.total}' => 4, 
            '{clients.total}' => 7,
            'clients' => array (
                    array ('{client.name}' => 'Yung Cet 1', '{client.id}' => '12341', '{client.balance}' => '10'),
                    array ('{client.name}' => 'Yung Cet 2', '{client.id}' => '12342', '{client.balance}' => '55'),
                    array ('{client.name}' => 'Yung Cet 3', '{client.id}' => '12343', '{client.balance}' => '-100'),
                    array ('{client.name}' => 'Yung Cet 4', '{client.id}' => '12344', '{client.balance}' => '0'),
                    array ('{client.name}' => 'Yung Cet 5', '{client.id}' => '12345', '{client.balance}' => '-60'),
                    array ('{client.name}' => 'Yung Cet 6', '{client.id}' => '12346', '{client.balance}' => '30'),
                    array ('{client.name}' => 'Yung Cet 7', '{client.id}' => '12347', '{client.balance}' => '30')
                ),
            'clients_test' => array (
                    array ('{client.name}' => 'Yung Cet 1', '{client.id}' => '12341', '{client.balance}' => '10'),
                    array ('{client.name}' => 'Yung Cet 2', '{client.id}' => '12342', '{client.balance}' => '55'),
                    array ('{client.name}' => 'Yung Cet 3', '{client.id}' => '12343', '{client.balance}' => '-100'),
                    array ('{client.name}' => 'Yung Cet 4', '{client.id}' => '12344', '{client.balance}' => '0'),
                    array ('{client.name}' => 'Yung Cet 5', '{client.id}' => '12345', '{client.balance}' => '-60'),
                    array ('{client.name}' => 'Yung Cet 6', '{client.id}' => '12346', '{client.balance}' => '30'),
                    array ('{client.name}' => 'Yung Cet 7', '{client.id}' => '12347', '{client.balance}' => '30')
                ),
            'users' => array (
                    array ('{users.name}' => 'Yung Cet', '{users.role}' => 'Software Engineer'), 
                    array ('{users.name}' => 'Cedric Maenetja', '{users.role}' => 'Managing Director')
                ), 
            'products' => array (
                    array ('{products.name}' => 'Product 1', '{products.desc}' => 'description'), 
                    array ('{products.name}' => 'Product 2', '{products.desc}' => 'description'),
                    array ('{products.name}' => 'Product 3', '{products.desc}' => 'description'), 
                    array ('{products.name}' => 'Product 4', '{products.desc}' => 'description')
                )
        );
    
    $htmlparser = new App\Custom\HTMLParser (file_get_contents ('__INDEX__'), $data); // do not change _INDEX_, this refers to the HTML on this editor
    $htmlstring = $htmlparser->GetSubstitutedString();
    
    // add a return statement to render the HTML in the browser
    return (App\Custom\Error::IsAnError ($htmlstring)) ? $htmlstring->GetError() : $htmlstring;