I want to use a variable inside an HTML-String of another PHP-File template.php in my PHP-File constructor.php. 
I´m searched on Stackoverflow for a workaround to include the content of the other PHP-File. I included the following code into constructor.php because its known to be more safe instead of using file_get_contents(); Source:
function requireToVar($file){
    ob_start();
    require($file);
    return ob_get_clean();
}
The rest of constructor.php looks like this:
...
    $sqli = mysqli_query($mysqli, "SELECT ...");
    if(mysqli_num_rows($sqli) > 0){
        $ii = 0;
        while ($row = $sqli->fetch_assoc()) {
            $ii++;
            if($row['dummy']=="Example"){
                $content.=requireToVar('template.php');
...
The template.php looks like this:
<?php echo "
   <div class='image-wrapper' id='dt-".$row['id']."' style='display: none;'>
   ...
   </div>
"; ?>
The constructor.php doesn´t recognize the var $row['id'] inside the string of template.php as its own variable and also doesn´t execute it. The variable definitely works for the other code in constructor.php.
If I´m copy&paste the code of template.php into constructor.php after $content.= its working like a charm. But I want to restructure my constructor.php because its getting to big and this way its easier to customize.
I don´t know how to describe this problem more exactly, but I´m hoping this title fits to my problem.
 
     
     
     
    