Transformers

Transformers modify extracted token values — converting types, manipulating strings, or setting defaults. Apply them with the colon syntax: {Token:Transformer()}.

String Manipulation

Transformer	Arguments	Description
`Trim()`	—	Removes leading and trailing whitespace
`ToUpper()`	—	Converts to uppercase
`ToLower()`	—	Converts to lowercase
`TitleCase()`	—	Converts to title case
`Remove('text')`	text to remove	Removes all occurrences of the specified text
`RemoveStart('prefix')`	prefix	Removes the specified prefix
`RemoveEnd('suffix')`	suffix	Removes the specified suffix
`Replace('from','to')`	from, to	Replaces all occurrences of one string with another
`RegexReplace('pattern','replacement')`	regex, replacement	Replaces regex matches (1s timeout)
`Truncate(n)`	max length	Truncates to the specified maximum length
`Split('delimiter')`	delimiter	Splits on delimiter, returns array
`SubstringBefore('text')`	search string	Extracts text before first occurrence
`SubstringAfter('text')`	search string	Extracts text after first occurrence
`SubstringBeforeLast('text')`	search string	Extracts text before last occurrence
`SubstringAfterLast('text')`	search string	Extracts text after last occurrence

Trim

var template = "Value: {Name:Trim()}";
// Input: "Value:   Alice   " → Name = "Alice"

ToUpper / ToLower

var template = "Code: {Code:ToUpper()}";
// Input: "Code: abc123" → Code = "ABC123"

TitleCase

var template = "Name: {Name:TitleCase()}";
// Input: "Name: john doe" → Name = "John Doe"

Remove

var template = "Value: {Value:Remove('$')}";
// Input: "Value: $42.00" → Value = "42.00"

RemoveStart

var template = "Id: {Id:RemoveStart('ID-')}";
// Input: "Id: ID-12345" → Id = "12345"

RemoveEnd

var template = "File: {File:RemoveEnd('.txt')}";
// Input: "File: readme.txt" → File = "readme"

Replace

var template = "Tags: {Tags:Replace(',',' | ')}";
// Input: "Tags: red,green,blue" → Tags = "red | green | blue"

RegexReplace

var template = "Phone: {Phone:RegexReplace('\\D','')}";
// Input: "Phone: (555) 867-5309" → Phone = "5558675309"

Truncate

var template = "Bio: {Bio:Truncate(20)}";
// Input: "Bio: A very long biography text" → Bio = "A very long biograph"

Split

var template = "Tags: {Tags:Split(',')}";
// Input: "Tags: red,green,blue" → Tags = ["red", "green", "blue"]

SubstringBefore

var template = "Email: {User:SubstringBefore('@')}";
// Input: "Email: alice@example.com" → User = "alice"

SubstringAfter

var template = "Path: {Rest:SubstringAfter('/')}";
// Input: "Path: /home/alice/docs" → Rest = "home/alice/docs"

SubstringBeforeLast

var template = "Path: {Dir:SubstringBeforeLast('/')}";
// Input: "Path: /home/alice/docs" → Dir = "/home/alice"

SubstringAfterLast

var template = "Email: {Domain:SubstringAfterLast('@')}";
// Input: "Email: alice@example.com" → Domain = "example.com"

Type Conversion

Transformer	Arguments	Description
`ToInt()`	—	Converts to `int`
`ToDecimal()`	—	Converts to `decimal`
`ToBoolean()`	—	Converts to `bool` (true/false, yes/no, on/off, 1/0)
`ToGuid()`	—	Converts to `Guid`
`ToDateTime('format',...)`	format strings	Converts to `DateTime` using specified formats
`ToDateTimeUtc('format',...)`	format strings	Converts to UTC `DateTime`

ToInt

var template = "Count: {Count:ToInt()}";
// Input: "Count: 42" → Count = 42 (int, not string)

ToDecimal

var template = "Price: {Price:ToDecimal()}";
// Input: "Price: 9.99" → Price = 9.99 (decimal, not string)

ToBoolean

var template = "Active: {IsActive:ToBoolean()}";
// Accepts: true/false, yes/no, on/off, 1/0

ToGuid

var template = "Id: {Id:ToGuid()}";
// Input: "Id: 550e8400-e29b-41d4-a716-446655440000" → Id = Guid

ToDateTime

var template = "Date: {Created:ToDateTime('dd/MM/yyyy','yyyy-MM-dd')}";
// Tries each format in order until one works

ToDateTimeUtc

var template = "Timestamp: {Ts:ToDateTimeUtc('yyyy-MM-ddTHH:mm:ss')}";
// Input: "Timestamp: 2025-12-25T09:00:00" → Ts = DateTime (UTC kind)

Value Modification

Transformer	Arguments	Description
`Set('value')`	fixed value	Overrides extracted value with a fixed string
`DefaultValue('fallback')`	fallback value	Returns fallback when extracted value is null or empty

Set

var template = "Role: {Role:Set('admin')}";
// Regardless of what Role matches, it is overridden to "admin"

DefaultValue

var template = "Status: {Status:DefaultValue('Unknown')}";
// If Status is empty or missing, defaults to "Unknown"

Chaining Transformers

Chain multiple transformers with commas. They execute left-to-right:

var template = "Email: {Email:Trim(),ToLower(),Truncate(50)}";
// 1. Trim whitespace → 2. Convert to lowercase → 3. Truncate to 50 chars

Transformers and validators can be mixed in the same chain. Validators run after transformers have modified the value.