Search code examples
phpverificationhtml

Closing HTML Tags Automatically

I've allowed users to use <pre></pre> tags to display code in comments and articles, but I've come across a problem that I'm struggling to solve. When a user fails to close an HTML tag, for example:

    <pre>
        <html>
            <head>

            </head>
    </pre>

the comment appears to be blank. What I'm looking for is some sort of function that will automatically close any HTML tags that the user missed.

Thanks in advance.

Solution

  • Well it's going to get nasty if you dont use a framework but your courage is admired. Hopefully this will be a nudge in the right direction.

    The simplest, non-framework solution I can think of is using a stack to push and pop tags while parsing the string from the user.

    pseudo code 

    userData = getUserData();
stack = array();
loop (line in userData) {
   matches = search for "<*>"; // may have multiple on one line
   loop (match in matches) {
      tagName = getTagNameFrom(match);
      if ("/" is not found) {
         push tagName on stack;
      } else if ("/" is found) {
         pop tagName off stack; 
         // There was an error if the stack is
         // empty or the tagName that was popped was not
         // the same.
      }
   }
}

    This is by no means comprehensive and a framework is really recommended here, but hopefully it can help out a bit.