TalkPHP - BB Code

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Jmz	10-24-2007 10:19 PM

BB Code

Hi,

Whats the best way of adding bb code to a variable?

I've been playing about with a function using str_replace but I have also read that using preg_replace is more efficient and safer, is this true?

Is there a better way I haven't heard of?

Wildhoney

10-24-2007 10:38 PM

I doubt it being more efficient for a simple BB parser. Safer, definitely, because with regex you can say if it doesn't have a closing tag then ignore it. That way you can ensure every single tag is closed and thus not affecting the rest of your website.

As for the answer, well, I'll let someone else answer that :) ! As I know they are typing as I type this.

bluesaga

10-24-2007 10:45 PM

I think this is what you mean:

PHP Code:


		
			

function BBParser($szInput)
{

 $aBBPattern = array(
                     '[b](.*?)[/b]' => '<b>\\1</b>',
                     '[i](.*?)[/i]' => '<i>\\1</i>'
                     );

 foreach( $aBBPattern as $szKey => $szValue )
 {
    $szPattern = '/'. preg_quote( $szKey, '/' ) .'/is';
    $szInput    = preg_replace( $szPattern, $szValue, $szInput );
 }

 return $szInput;

}

Jmz	10-25-2007 08:07 AM

Thanks for that :)

If I used the method above, how would I do things like:

Code:

[ u r l=http://www.google.com]Google[/ u r l ]

(without the spaces)

bluesaga

10-25-2007 08:30 AM

You do need to be able to understand preg pattern matching to be able to understand this, but something like:

PHP Code:


		
			

function BBParser($szInput)
{

 $aBBPattern = array(
                     '[b](.*?)[/b]' => '<b>\\1</b>',
                     '[i](.*?)[/i]' => '<i>\\1</i>',
                     '[url=([^\]+?)](.*?)[/url]' => '<a href="\\1">\\2</a>'
                     );

 foreach( $aBBPattern as $szKey => $szValue )
 {
    $szPattern = '/'. preg_quote( $szKey, '/' ) .'/is';
    $szInput    = preg_replace( $szPattern, $szValue, $szInput );
 }

 return $szInput;

}

Remember this isnt tested, but the theory is there :)

Jmz	10-25-2007 09:16 AM

Thanks :)

I'll test it out now.

Jmz	10-25-2007 09:40 AM

Nope, I'm lost lol :(

What I have at the minute is:

PHP Code:


		
			
function BBCode($text){
$BBCode = array("&" => "&amp;",
"<" => "&lt;",
">" => "&gt;",
"[b]" => "<b>",
"[/b]" => "</b>",
"[i]" => "<i>",
"[/i]" => "</i>",
"[u]" => "<u>",
"[/u]" => "</u>",
"[img]" => "<img src='",
"[/img]" => "'>");
$parsedtext = str_replace(array_keys($BBCode), array_values($BBCode), $text);
return $parsedtext;
}

That works fine but I want to change it to do it your way.

I've tried:

PHP Code:


		
			
function BBcode($szInput)
{

 $aBBPattern = array(
                     '[b](.*?)[/b]' => '<b>\\1</b>',
                     '[i](.*?)[/i]' => '<i>\\1</i>',
                     '[url=([^\]+?)](.*?)[/url]' => '<a href="\\1">\\2</a>'
                     );

 foreach( $aBBPattern as $szKey => $szValue )
 {
    $szPattern = '/'. preg_quote( $szKey, '/' ) .'/is';
    $szInput    = preg_replace( $szPattern, $szValue, $szInput );
 }

 return $szInput;

}

Although I get no errors with the above code the bb tags aren't replaced, where am I going wrong?

Gurnk

10-25-2007 10:42 AM

How are you setting up the string you want to parse?

It should look like this I think

PHP Code:


		
			
 $sting = "[ b ]My BBC[/ b]";
echo BBcode($string);

Wildhoney

10-25-2007 11:26 AM

I've redone your regex and removed the preg_quote.

PHP Code:


		
			
function BBcode($szInput)
{
 $aBBPattern = array(
                     '\[b\](.*?)\[\/b\]' => '<b>\\1</b>',
                     '\[i\](.*?)\[\/i\]' => '<i>\\1</i>',
                     '\[url="([http:\/\/]+[^"]+)"\](.*)\[\/url\]' => '<a href="\\1">\\2</a>'
                     );

 foreach( $aBBPattern as $szKey => $szValue )
 {
    $szPattern = '/'. $szKey .'/isU';
    $szInput    = preg_replace( $szPattern, $szValue, $szInput );
 }

 return $szInput;

}

Salathe

10-25-2007 11:35 AM

The problem with bluesaga's function is that the patterns are fed into preg_quote which renders them useless for your needs.

An amended function could be something along the lines of:

PHP Code:


		
			
function BBcode($szInput)
{    
    $aBBPattern = array(
        '<strong>\\1</strong>'  => '#\[b\](.*?)\[/b\]#is',
        '<em>\\1</em>'          => '#\[i\](.*?)\[/i\]#is',
        '<u>\\1</u>'            => '#\[u\](.*?)\[/u\]#is',
        '<img src="\\1" />'     => '#\[img\](.*?)\[/img\]#i',
        '<a href="\\1">\\1</a>' => '#\[url\](.*?)\[/url\]#i',
        '<a href="\\1">\\2</a>' => '#\[url=([^\]]+?)\](.*?)\[/url\]#i'
    );
    return preg_replace(array_values($aBBPattern), array_keys($aBBPattern), $szInput);
}

Jmz	10-25-2007 11:41 AM

Thats great, thanks a lot.

bluesaga

10-25-2007 11:51 AM

Lol, yea sorry i forgot to escape the patterns properly, got confused with the preg_quote....

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