如何创建php正则表达式

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;
}

Answer 1

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"