BBCode using Preg_Replace - Page 2

Geert · 04-07-2008, 12:49 PM

Quote:

Originally Posted by Orc

Okay, I tried my own [url], and it messed up if there are two url bbcodes in the place.

Same trick. Make .* lazy: .*?

Orc · 04-07-2008, 12:51 PM

Quote:

Originally Posted by Geert

Same trick. Make .* lazy: .*?

Can you tell me more about ".*?" ? Cause it worked perfectly, and I use it though I hardly know what it means >.<

delayedinsanity · 04-07-2008, 01:54 PM

Broken down, it means:

. matches any character except a newline
* matches whatever precedes it (in this case the ".") 0 or more times.
? matches as few times as possible.

So .* acts a lot like a wildcard when you need to match a variety of possible strings, however, it's greedy, so if you're trying to match

(b)text(/b)

in a string that contains

(b)something(/b) and (b)something else(/b) followed by (b)this(/b)

because it's greedy, it will match from the first (b) all the way down to the last (/b). Make it lazy, and .* only matches as little as possible till it finds something that'll complete the pattern, such as the first (/b) instead of the last one.

For the sake of this post, pretend that all ('s and )'s are ['s and ]'s, because I'm apparently too retarded to figure out how to display them without having them parsed.

Orc · 04-07-2008, 01:57 PM

Quote:

Originally Posted by delayedinsanity

Broken down, it means:

. matches any character except a newline
* matches whatever precedes it (in this case the ".") 0 or more times.
? matches as few times as possible.

So .* acts a lot like a wildcard when you need to match a variety of possible strings, however, it's greedy, so if you're trying to match

(b)text(/b)

in a string that contains

(b)something(/b) and (b)something else(/b) followed by (b)this(/b)

because it's greedy, it will match from the first (b) all the way down to the last (/b). Make it lazy, and .* only matches as little as possible till it finds something that'll complete the pattern, such as the first (/b) instead of the last one.

For the sake of this post, pretend that all ('s and )'s are ['s and ]'s, because I'm apparently too retarded to figure out how to display them without having them parsed.

Thanks!

Hey, if you're trying to replace a whole string, and want one piece of the string to still be in tact, how do you do that?

delayedinsanity · 04-07-2008, 02:20 PM

I'm sure you could do it any number of ways, but if I wanted to replace "The quick brown fox jumps over the lazy dog" with "A little brown fox gets eaten by my cat", I might use /^[\w\s]+(brown fox)[\w\s]+$/i with a replacement string of "A little $1 gets eaten by my cat"...
-m

Nor · 04-11-2008, 01:22 AM

Code:

$pattern[0] = "/\[b\](.*?)\[\/b\]/i";

Ain't good enough :)

What If I wanted to hmm check the bold tag like this:

Code:

[ b]
test
[/b ]

That little regex wouldn't check it it'll display it like it is.

Thats why you use the "s" modifier :) to make the "." match new lines also :)

Code:

$pattern[0] = "/\[b\](.*?)\[\/b\]/is";

Now

Code:

[b ]
test
[/b ]

Turns into

Code:

<strong>
test
</strong>

I taught my self something :)

(remove the spaces in the [ b] tags -.-.. stupid code tag is broke lol..)

Evulness · 12-09-2008, 06:11 PM

Using the tutorial at the begining of this topic, i created the following:

Code:

function bbcode($input){

        $code = array('/\[b\](.*?)\[\/b\]/is',
                       '/\[i\](.*?)\[\/i\]/is',
                       '/\[u\](.*?)\[\/u\]/is',
                       '/\[url=(.*?)\](.+?)\[\/url\]/is',
                       '/\[quote\](.*?)\[\/quote\]/is',
                       '/\[color=(.*?)\](.*?)\[\/color\]/is');

        $replace = array('<strong>$1</strong>',
                      '<i>$1</i>',
                      '<u>$1</u>',
                      '<a href="$1">$2</a>',
                      '<br /><div class="quote">$1</div><br />',
                      '<span style="color: $1;">$2</span>');

        $text = preg_replace($code, $replace, $input);

     return $text;

}
echo bbcode('This is a [b]test[\b].');

It isn't replacing anything. Anyone mind poking around a bit and seeing what the issue is?

Thanks.

Salathe · 12-09-2008, 06:50 PM

Quote:

Originally Posted by Evulness

It isn't replacing anything. Anyone mind poking around a bit and seeing what the issue is?

Thanks.

The closing bbcode tag needs a forward slash, not back. E.g.

PHP Code:


			
//                             ↓ forward slash

echo bbcode('This is a [b]test[/b]');

Evulness · 12-09-2008, 07:30 PM

The smallest errors are a hard to spot sometimes.

Thank you!

Wildhoney · 12-09-2008, 11:16 PM

I was reading the following proposal on Zend_Filter_Bbcode the other day, and somebody on there, as well as on other similar proposals, mentioned that we shouldn't use regular expressions because it might end up with badly formed XHTML. I didn't quite understand that, so could somebody please elucidate for me.

ETbyrne · 12-10-2008, 02:43 AM

*sigh, it is a little known fact that PHP actually has its own built in functions for parsing bbcode.

> http://us.php.net/bbcode

Was going to make an article on it... oh well, just consider it an early Christmas gift.

Just comes to show always check the manual before trying to do it yourself!