[RESOLVED] BB code parser; need a little help.

spookztar

Hi guys,

I'm having a bit of trouble with creating a BB code parser. I have the following so far:

$productdescription = (isset($_POST['description'])) ? strip_tags($_POST['description']) : NULL;

   $bb[] = "[b]";
   $bb[] = "[eb]";
   $bb[] = "[u]";
   $bb[] = "[eu]";
   $bb[] = "[r]";
   $bb[] = "[er]";
   $bb[] = "[g]"; 
   $bb[] = "[eg]";
   $bb[] = "[lb]";
   $bb[] = "[nl]"; 
   $bb[] = "[enl]";
   $bb[] = "[li]"; 
   $bb[] = "[eli]";
   $bb[] = "[bl]";
   $bb[] = "[ebl]";

   $html[] = "<strong>";
   $html[] = "</strong>";
   $html[] = "<u>";
   $html[] = "</u>";
   $html[] = "<span style=\"color: red\">";
   $html[] = "</span>";
   $html[] = "<span style=\"color: green\">";
   $html[] = "</span>";
   $html[] = "<br />";
   $html[] = "<ol>";
   $html[] = "</ol>";
   $html[] = "<li>";
   $html[] = "</li>";
   $html[] = "<ul>";
   $html[] = "</ul>";
for ($bbnr = 0; $bbnr <= 14; ++$bbnr)
    {
    $dirtydescription = str_replace($bb[$bbnr], $html[$bbnr], $productdescription);
    $clean_description = $dirtydescription;
    }
echo $clean_description;

How do I angle this one? Or is the general approach all wrong? It works fine with just one replacement, but as soon as I add more tags to either tag list, it just outputs the string with the BB tags, no conversion takes place. The problem seems to be that the $clean_description variable keeps overwriting itself, isn't there a fancy way of incrementally ... what can I say.. refreshing it, without loosing the result of previous iterations?

Bye,

NogDog

Because of the complexity of the nesting of such tags, I would recommend implementing the PECL BBCode extension or the PEAR HTML_BBCodeParser package both for speed and efficiency as well as not having to re-invent the wheel.

spookztar

Thanx for responding, but that's not really going to teach me how to program, is it? 🙂

halojoy

the problem is here:

for ($bbnr = 0; $bbnr <= 14; ++$bbnr)
{
    $dirtydescription = str_replace($bb[$bbnr], $html[$bbnr], $productdescription);
    $clean_description = $dirtydescription;
}

In first run you use '$product'
result is in '$dirty' .. $product stays the same all the time!
Next run uses $product .. to make a new version of $dirty = The first is OVERWRITTEN
.. also put: $clean = $work_var AFTER (outside of) loop

try this way to use SAME variable within the LOOP

$html[] = "<ul>";
$html[] = "</ul>";

$work_var = $productdescription; // leave the original intact, just in case

// loop
for ($bbnr = 0; $bbnr <= 14; ++$bbnr)
{
    $work_var = str_replace($bb[$bbnr], $html[$bbnr], $work_var);
}

// new version to display 
$clean_description = $work_var;

// display
echo $productdescription; // let us compare with original input
echo '<br />';
echo $clean_description;

halojoy

hey again

in fact you do not need to loop

Read this:
http://docs.php.net/str_replace

str_replace() can take your 2 arrays as arguments.

So I think following will work .. and be FASTER than a LOOP!
...and of course less code 🙂

$html[] = "<li>";
$html[] = "</li>";
$html[] = "<ul>";
$html[] = "</ul>";

// Do the replacing
$clean_description = str_replace($bb, $html, $productdescription);

// Display result
// Let us compare original input with clean
echo $productdescription;
echo '<br />';
echo $clean_description;

spookztar

Ok? str_replace() can take whole arrays as arguments? Wasn't aware of that one, thought I had to do it one tag-set at a time. I'll try it when I get home and report back on the results.

Thanx. 🙂

NogDog

You might want to take a look at [man]preg_replace[/man], which also takes array arguments, if you find you need to do more complex operations. str_replace() will be faster, though, so use it if it is sufficient. Neither of these, however, will likely be as fast as the [man]bbcode[/man] extension, as it uses a different algorithm and is based on compiled C code.

spookztar

Ok, appreciate the additional info, Nogdog. Halojoy's suggestion of 05-15-2008 08:29 appears to have done the trick. Apparently, this was a lot less complicated than I imagined it to be.

Thanx guys.