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Formula - regexgroup
The regexGroup Formula function returns the value of a capturing group of a regular expression, instead of the whole match that regex returns.
Syntax
regexGroup('expression', 'groups', content)
Parameters
| Parameter | Required | Description |
|---|---|---|
'expression' |
Yes | A .NET regular expression with at least one capturing group ( ), in single quotes. Backslashes are written once ('\d+'). |
'groups' |
Yes | The number of the capturing group to return, such as '1' for the first group. The screenshots show both '1' and 1. |
content |
Yes | The text to search: body, context, or the result of another function (see Formula language rules). |
Returns
The value of the selected group for every match, one value each; duplicates are collapsed. When a group repeats inside one match (for example (…){4}), the value from its last repetition is returned. When nothing matches, nothing is returned.
Examples
Example 1: Read the order IDs from the body
Input
ID=123,CUSTOMER=1
ID=456,CUSTOMER=2
Formula
regexGroup('ID=(\d+)', '1', body)
Result
123
456
Group 1 captures only the digits after ID=, so the ID= prefix is not part of the result.
Example 2: Read the fourth field of a pipe-delimited context value
Input
The Message Context key OrderRecord holds a pipe-delimited order record:
| Key | Value |
|---|---|
| OrderRecord | ORD|101|ExampleCompany1|456|Company Name ACME |Dieselgate valley 1|123 45|Flameburg| |
Formula
regexGroup('^(?:(.*?)\|){4}', 1, context('OrderRecord'))
Result
456
(?:(.*?)\|){4} repeats four times from the start of the value; group 1 keeps the last repetition, the fourth field (counted from 1), 456.
Notes
\|matches a literal pipe; an unescaped|means "or" in a regular expression.- To return the whole match instead of a group, use regex.
- For one pattern on the body, the RegEx with capturing groups plugin returns groups without a formula, and accepts several group numbers or names. See Choose a plugin.