"placeholder" of "textarea" does not appear

Question

I have a textarea with a placeholder which according to the documentation ^(English) is perfectly valid and should work:

Example in Jsfiddle

Part of the form

<?php

/* Apenas o código referente à textarea
 */
$oc_message = isset($postArr["oc_message"]) ? cleanStr($postArr["oc_message"]) : '';

$form = '
<div class="form-group">
    <label for="oc_message">
        '.ucfirst(I18N_WORD_MESSAGE).' <small class="text-danger">*</small>
    </label>
    <textarea class="form-control" id="oc_message" name="oc_message" placeholder="'.I18N_PLACEHOLDER_MESSAGE.'" rows="10">
       '.$oc_message.'
    </textarea>
</div>';
?>

However, the text of placeholder does not appear in the same!

HTML generated:

<div class="form-group">
    <label for="oc_message">
        Mensagem 
        <small class="text-danger">*</small>
    </label>
    <textarea rows="10" placeholder="Introduza a sua mensagem" name="oc_message" id="oc_message" class="form-control">                          
    </textarea>
</div>

Question

Why is the placeholder is not appearing?

Answer 1

The problem is that the placeholder appears only when the textarea is empty, without any text. Yours is not, you have inserted the indentation spaces in it.

Try:

<form action="" method="post">
    <div>
        <textarea id="message" name="message" placeholder="A sua mensagem"></textarea>
    </div>
</form>

Answer 2

In the case of tag textarea, to the placeholder function, tag opening and closing must be on the same line and no spaces.

In your case the textarea thinks the line break is content and the placeholder does not appear.

So to use:

<textarea id="message" name="message" placeholder="A sua mensagem"></textarea>

Fiddle