The Labeler transformation is a passive transformation that analyzes input port fields and writes text labels that describe the data in each field.
You use a Labeler transformation when you want to understand the types of information that a port contains. Use a Labeler transformation when you do not know the types of information on a port, or when you want to identify records that do not contain the expected types of information on a port.
A label is a string one or more characters that describes an input string. You configure the Labeler transformation to assign labels to input strings based on the data that each string contain.
When you configure the transformation, you specify the types of character or string to search for, and you specify the label that the transformation writes as output when it finds the associated character or string. You enter the character and string types to search for, and the labels to use, when you configure a labeling operation. Or, you use reference data objects to specify the characters, strings, and labels.
You configure the transformation to perform character labeling or token labeling:
Character Labeling
Writes a label that describes the character structure of the input string, including punctuation and spaces. The transformation writes a single label for each row in a column. For example, the Labeler transformation can label the ZIP Code 10028 as "nnnnn," where "n" stands for a numeric character.
Token Labeling
Writes a label that describes the type of information in the input string. The transformation writes a label for each token identified in the input data. For example, you can configure the Labeler transformation to label the string "John J. Smith" with the tokens "Word Init Word."
A token is a delimited value in an input string.
When the Labeler finds a character or string that matches a label that you specify, it writes the label name to a new output port.
The Labeler transformation uses reference data to identify characters and tokens. You select the reference data object when you configure an operation in a Labeler strategy.