Question

When mixing PHP and HTML, what is the proper indentation style to use? Do I indent so that the outputted HTML has correct indentation, or so that the PHP/HTML mix looks properly formatted (and is thus easier to read)?

For example, say I have a foreach loop outputting table rows. Which one below is correct?

PHP/HTML mix looks correct:

<table>
  <?php foreach ($rows as $row): ?>
    <tr>
      <?php if ($row->foo()): ?>
        <?php echo $row ?>
      <?php else: ?>
        Something else
      <?php endif ?>
    </tr>
  <?php endforeach ?>
</table>

Outputted HTML looks correct:

<table>
<?php foreach ($rows as $row): ?>
  <tr>
  <?php if ($row->foo()): ?>
    <?php echo $row ?>
  <?php else: ?>
    Something else
  <?php endif ?>
  </tr>
<?php endforeach ?>
</table>

I’ve found that when I run into this situation (quite frequently), I don’t have a standard style to use. I know that there may not be a “correct” answer, but I’d love to hear thoughts from other developers.

Answer 1

The PHP and the HTML should each be indented so that they are correct with respect to themselves in source form, irrespective of each other and of outputted form:

<table>
<?php foreach ($rows as $row): ?>
    <tr>
    <?php if ($row->foo()): ?>
        <?php echo $row ?>
    <?php else: ?>
        Something else
    <?php endif ?>
    </tr>
<?php endforeach ?>
</table>