Question

How do I modify and insert form elements using PHP?

I have a form assigned to a variable in PHP like so:

$the_original_form = '
<form method="post" action="whatever.php">
<input type="text" name="iamtextfield" id="textisme">
<input type="file" name="iamfilefield" id="fileisme">
<input type="hidden" name="hideme" value="nope">
</form>
';

I have a second variable:

$put_me_on_the_top = '<div class="getinme">';

And a third variable:

$put_me_on_the_bottom = '</div><div class="justsomethingelse">hi there</div>';

And a modified form element of:

$i_have_changed = '<input type="file" name="filepartdeux" id="iamabetterfile">';

And I want to end up with:

$the_modified_form = '
<form method="post" action="whatever.php">
<input type="text" name="iamtextfield" id="textisme">
<div class="getinme">
    <input type="file" name="filepartdeux" id="iamabetterfile">
</div>
<div class="justsomethingelse">hi there</div>
<input type="hidden" name="hideme" value="nope">
</form>
';

Answer 1

You can load a mal-formed or well formed HTML document into a new DOMDocument and manipulate it as you would XML.

$doc = new DOMDocument();

$doc->loadHTML($the_original_form);

// You can manipulate using the DOM object just follow the PHP manual for usage
foreach ($doc->childNodes as $element)
{
    // Evaluate elements here and insert / extract / delete as necessary
}

• Malformed HTML will throw errors from DOMDocument, you will need methods to deal with those errors. Try and use well formed HTML as much as you can.