substring regex...

[dresden_phoenix]

Is there a way , within ONE PHP regex statement , to evaluate only part of a regex selected string? Hmm.. that doesnt seem to explain what I mean very well. Lets, for example, say you had a string of text, SOME of it contained something SIMILAR to HTML tags.. "\n<ol>\n" and "\n</ol>\n", so you wanted to preg_replace for "\n\*" BUT only in the text contained between ANY occurrence of "\n<ol>\n" and "\n</ol>\n".

So far the only way I see of accomplishing this to use preg_match, a remembering array, run the sub-regex on the captured result from the preg_match, then another loop str_replacing items in the remembering array with the regexed captured result from the preg_match. Which is rather convoluted, even just to describe.

Any suggestions would be greatly appreciated.

[ServerStorm]

Hi dresden_phoenix

Is this what your looking for:

$text = "\n<ol>\n <li>This is the text between the ol. </li> \n</ol>\n";

/*
* Regex searches on the new lines and the ols, 
* then it uses a group match to get the text inbetween.
*/$match = preg_match("/\\n<ol>\\n(.*)\\n<\/ol>\\n/", $text , $matches);
print_r($matches);

/* Outputs */
Array ( 
[0] => This is the text between the ol.  
[1] => <li>This is the text between the ol.</li> 

Regards,
Steve

[StarLion]

I think the simple answer is 'no, it will require 2 statements.'

[ServerStorm]

Wow, I have to stop answering Dresden's posts, no fault of his own but I seem to misinterpret his needs way too often. I re-read what you asked have been trying a number of things but @StarLion ; has seemed to tell you correctly.

I promise I will steer clear of your questions in the future and sorry for the wasted post.

Regards,
Steve

[dresden_phoenix]

That suck, as normally you actually end up answering my Q's correctly, Storm.

@ star...

Does that mean looping statements? I mean if the original string contained multiple OLs

[ServerStorm]

That suck, as normally you actually end up answering my Q's correctly, Storm.

Thanks... I guess I'll keep trying and glad that I have not put you off

Could you give a full example in an code block an specific example, is it:

• '\n<ol>\n <li>some text \n and more text</li>\n</ol>\n' : so you would want \n<ol>\n <li>some text</li>\n</ol>\n or
• '\n<ol>\n \n<li>some text</li>\n</ol>\n' : so it would become \n<ol>\n \n</ol>\n or
• something else?

I have been fiddling and found something that can give you \n<ol>\n <li></li>\n</ol>\n but I am not sure if this is helpful because if you are trying to preserve some text inside the <ol> and/or the <li> then I wanted to try something else.

Regards,
Steve

[wonshikee]

If I understand your question right, you have to use lookahead and lookbehind.

[dresden_phoenix]

OK.. so lets say you have a block of text, you want to change any AND ALL \n* that happens to be within <OL>/</OL> to <LI> ( just to keep this task 'simple') But what you dont whant to change is any \n* that are OUTSIDE the <OL>/</OL>:

"
<ol>
*Change us!
*list item
*list item
</ol>
lorem ipsum .. blah bla blah

*dont change me
*dont change me

more lorem ipsum

<ol>
*Change us also !
*list item
</ol>
lorem ipsu"


I am probably not doing this right, but the problem with look ahead/behind in this case is that then it only changes ONE of the \n* between the tags not all. What am searching for is a way to change all occurrences of a pattern within ONLY WITHIN all occurrences of another pattern.

[StarLion]

preg_match_all("<ol>.*?</ol>",$input,$blocks); //Find all OL's.
$store = $blocks; //Create a duplicate for later use.
$blocks = preg_replace("\n","<li>",$blocks); //Change the blocks.
$input = preg_replace($store,$blocks,$input); //Insert the replacements 

Note: This -will- fark up if you nest OL's.

I want to say this would be easier with a recursive DOM parser....

[ServerStorm]

Darn you @StarLion ; ! I have been trying to figure out the best way to do this and your solution is quite eligante!

Thanks,
Steve

[dresden_phoenix]

Sorry guys I had to put this on hold for while,

Star
I tired your suggestion, but i got the following sintax error

Warning: preg_replace(): Delimiter must not be alphanumeric or backslash in - on line 41 ( the last line of your code), I also had to add delimiters to the other preg_match and first preg_replace but i figured you left that for me to do. It appears the problem arises because the regex pattern stored in the array doesnt have a delimiter?

I tried the following alteration:

preg_match_all("#<ol>.*?</ol>#",$input,$blocks); //Find all OL's.
$store = $blocks; //Create a duplicate for later use.
foreach ($store as $k=>$v){$store[$k]="#$v#";}
$blocks = preg_replace("#\n#","<li>",$blocks); //Change the blocks.
$input = preg_replace(  $store ,$blocks,$input); //Insert the replacements  echo $input;
echo $input;

but it only changed the first \n*...:/


any suggestions. Either way thanks for your input on this.

[StarLion]

foreach ($store as $k=>$v){$store[$k]="#$v#";}

Why is that there?

EDIT: NM, silly me. need pattern delimiters.

[StarLion]

So i got a bit more refined. Go me.

echo preg_replace_callback("%<ol>.*?</ol>%s",create_function('$matches','return preg_replace("%\n%s","<li>",str_replace("\n</ol>","</ol>",$matches[0]));'),$input); 

[ServerStorm]

So i got a bit more refined. Go me.

echo preg_replace_callback("%<ol>.*?</ol>%s",create_function('$matches','return preg_replace("%\n%s","<li>",str_replace("\n</ol>","</ol>",$matches[0]));'),$input); 

Yes "Go you! @StarLion ;"! Nice work using the callback and nice example of use in this context!

[dresden_phoenix]

BRILLIANT, STAR!!!

Nice work using the callback and nice example of use in this context!

ditto and thanks so much