Question

I would like to allow only paragraphs and lists.

Actually i want to use the input to create a document in Open Document format. So I replace the tag <p> with the correct tag in ODF. But first, I’m trying to learn how to transform the markdown format into something I can use.

I could use the output of MarkdownPHP and replace tags in html to ODF tags, however i want to use only the paragraphs and lists. The Markdown generates much more than i need. If i miss any html tag the ODF document will break because it don’t understand html tags.

I believe it is possible to use a simple RegExp. But I don’t know how!

example:

My first line.

*    My first item.
*    My second item.

More text...

output:

<p>My first line.</p>
<ul>
    <li>My first item.</li>
    <li>My second item.</li>
</ul>
<p>More text...</p>

Answer 1

You can use the strip_tags() function to remove all tags other than the ones you want. Their contents will remain, but the tags themselves will be removed.

Try this:

$output = strip_tags($output, "<p><ul><ol><li>");

From there, you can just use str_replace() to change the remaining tags into their ODF counterparts. (If the tag format isn’t consistent coming out of your Markdown parser, then you can just use preg_replace() to handle the differences depending on the specific output).