RegExCapture Operator

Use the RegExCapture to capture a value from a string based on a regular expression.

What	Type
Syntax	RegExMatch(regEx, text)
regEx	string
text	any
Return type	string

RegExCapture supports two different modes of capturing values via a regular expression: Matching the entire regular expression, or matching the first group of the regular expression.

If regEx does not contain any regex groups, the entire capture (if the regular expression matches the text) will be returned. If the regular expression contains one or more groups, the first group's capture will be returned.

As a default (and currently not changeable), RegExCapture works in the multiline mode. This means that the caret ^ not only matches the beginning of the text string, but also the beginning of a line inside the text, if text contains line breaks. Likewise, $ not only matches the end of the string, but also the end of a line inside text.

Example: The following text (an email) is passed as the field $MailBody into the RegExCapture operator:

From: somebody@somewhere.com
To: me@myself.com
Subject: This is a subject line!
Body:
Hello Me,

This is an email.

Bye!

The following table illustrates the difference between the usage of groups and not:

regEx	returned string
^Subject: .*$	Subject: This is a subject line!
^Subject: (.*)$	This is a subject line!

In the first case, the regex does not contain any groups (introduced by parenthesises ( )), alas, the entire matched expression ("capture") is returned. In the second line, a group is used to extract only the actual subject line.

If multiple groups are used, the first one is returned (this may be subject to change in the future by introducing further operators).

Remark: In order to speed up the processing of the regular expression, the regEx parameter is assumed to be constant. Only in the first call, the regular expression will be compiled; the next times, it will just evaluate and match agains text. In short: regEx does not take dynamic content; or: just once.