Ignoring unclosed tags from another <div>?

Question

I have a website where members can input text using a limited subset of HTML. When a page is displayed that contains a user's text, if they have any unclosed tags, the formatting "bleeds" across into the next area. For example, if the user entered:

Hi, my name is <b>John

Then, the rest of the page will be bold.

Ideally, there'd be someting I could do that would be this simple:

<div contained>Hi, my name is <b>John</div>

And no tags could bleed out of that div. Assuming there isn't anything this simple, how would I accomplish a similar effect? Or, is there something this easy?

Importantly, I do not want to validate the user's input and return an error if they have unclosed tags, since I want to provide the "easiest" user interface possible for my users.

Thanks!

Answer 1

This can't be done.

Don't let users invalidate your HTML.

If you don't want to let users fix their errors, then try to clean it up automatically for them.

Answer 2

You can put the HTML snippet through Tidy, which will do its best to fix it. Many languages include it in some fashion or another, here for example PHP.

Answer 3

You can parse the data entered by the user. Thats what an XML does. You may need to parse or replace the standard html or xml symbols like '<', '>', '/', '&', etc... with '&lt', '&gt', etc...

In this way you can achieve whatever you want.

Answer 4

i have solution for php

<?php
    // close opened html tags
    function closetags ( $html )
        {
        #put all opened tags into an array
        preg_match_all ( "#<([a-z]+)( .*)?(?!/)>#iU", $html, $result );
        $openedtags = $result[1];
        #put all closed tags into an array
        preg_match_all ( "#</([a-z]+)>#iU", $html, $result );
        $closedtags = $result[1];
        $len_opened = count ( $openedtags );
        # all tags are closed
        if( count ( $closedtags ) == $len_opened )
        {
        return $html;
        }
        $openedtags = array_reverse ( $openedtags );
        # close tags
        for( $i = 0; $i < $len_opened; $i++ )
        {
            if ( !in_array ( $openedtags[$i], $closedtags ) )
            {
            $html .= "</" . $openedtags[$i] . ">";
            }
            else
            {
            unset ( $closedtags[array_search ( $openedtags[$i], $closedtags)] );
            }
        }
        return $html;
    }
    // close opened html tags

?>

you can use this function like

   <?php echo closetags("your content <p>test test"); ?>