how to create php regex

Question

I am trying to create a regex to replace a string. Here is my pattern:

\{mailMerge: details_activity_number\\}

When I do a search like this on a string like this:

hello {mailMerge: details_activity_number\}world

its fine. But, if there's a line break like this:

hello \{ mailMerge: details_activity_number\} world

it breaks. Here is my code in PHP:

 $pattern = '\{mailMerge: 'mailMerge: details_activity_number'\}'; $content = str_replace($pattern, $value, $content);

Can anyone help me with creating a pattern that would take into consideration possible line breaks/white spaces/etc to guarantee a match?

thanks

EDIT

private function findAndReplace($content, $mergedArray){ $test=$content; try{ foreach($mergedArray as $ArrayKey => $ArrayValue){ foreach ($ArrayValue as $key => $value) { $pattern = "\{\s*mailMerge:\s+". $key ."\s*\\\}"; if($value){ $test = preg_replace($pattern, $value, $test); }else{ $test = preg_replace($pattern, "No Value Exists", $test); } } } }catch(Exception $e){ throw $e; } return $test; }

Sometimes you have \{ and others you have {. Is the `\` required? — Michael Berkowski
– Michael Berkowski, Commented Feb 13, 2014 at 19:49
Do you want a regular expression or a literal string? str_replace is for replacing literals. There are no regular expression pattern characters in $pattern. — Barmar
– Barmar, Commented Feb 13, 2014 at 19:51
Not an answer to your question, but a couple of really good resources for RegEx are regular-expressions.info and Regex Buddy. — Eli
– Eli, Commented Feb 13, 2014 at 19:53

elixenide · Accepted Answer · 2014-02-13 20:44:26Z

The first version that you posted doesn't allow for any space between { and m. You need to do something like this:

\{\s*mailMerge:\s+details_activity_number\s*\\\}

The \s* means "match zero or more spaces (or other white space, like new lines) here." \s+ means "match one or more spaces (or other white space, like new lines) here."

NOTE: Your code above uses str_replace, but you are trying to do a regex replace. You need to use preg_replace instead of str_replace, like in this code:

$content = "\{mailMerge: 'mailMerge: details_activity_number'\}"; $content = preg_replace('/\{\s*mailMerge:\s+details_activity_number\s*\\\}/m', $value, $content);

EDIT BASED ON COMMENTS: Try this; it is working for me.

$value = "foo barrrrrr"; $content = "hello {mailMerge: details_activity_number\} world"; $content = preg_replace("/\\\\?\\{\s*mailMerge:\s+details_activity_number\s*\\\\?\\}/m", $value, $content); echo $content; // produces "hello foo barrrrrr world"

Thank you for your response. When I run this in a test site like: phpliveregex.com it's fine. But when I run it in my php code it still fails. do I have to escape the last two '\\' to make this work?
Try adding one more \ before the }. \\ just means an escaped \, so there's nothing escaping the }. You should also add /m (for "match across lines"), like this: /\{\s*mailMerge:\s+details_activity_number\s*\\\}/m
Thanks. Still no luck. Again, it works fine in a regex test site but when I run my code it fails (the returned string is empty). I added the full function, if that will help. I really appreciate your help with this, as I'm against a deadline.
I clarified my answer somewhat; the code at bottom should address your problems. Mostly, it has to do with additional escaping.
now I get an error saying " NO MATCHES. CHECK FOR DELIMITER COLLISION.

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