如何仅为论坛呈现某些html标签？

Question

I am currently building a forum and am trying to print out posts with formatting (bold, italicized, images, etc.) The user inputs the text using http://summernote.org/ My php code is currently set to:

echo nl2br(e($content));

Which prints out: (printing the actual tags)

<p><b>asdffddd d d d d </b></p>

When I surround my echo function with htmlspecialchars_decode, it renders every single html tag. This is obviously not ideal, because users could put things like iframe's or div's and break the layout of my page.

What would be the best way to only render the following tags

<b>
<i>
<u>
<p>
<h1-6>
<img>
<a>
<span>
<ul>
<ol>
<li>

I would still like it to display non-allowed tags in text form, just not render them.

Answer 1

Use strip_tags to achieve this.

<?php
$html = 'Your html';
$allowableTags = '<a><b>'; // add allowable tags
echo strip_tags($html,$allowableTags);
?>

I hope this helps.