Mapping Data in Flow Services
Because systems rarely produce data in the exact format that other systems need, you commonly need to build flow services that perform data transformations. Data transformation resolves differences in the way data is represented within documents that applications and systems exchange. In Designer, data transformations can be accomplished by mapping data. By mapping, you can accomplish the following types of transformations:
Name transformations. This type of transformation resolves differences in the way data is named. For example, one service or document format might use
telephone as the name of the variable for telephone number information and another might use
phoneNumber. When you perform name transformations, the value and position of a variable in the document structure remains the same, but the name of the variable changes.
Structural transformations.This type of transformation resolves differences in the data type or structure used to represent a data item. For example, one service or document format might put the telephone number in a String called
telephone, and the next may expect to find it nested in a Document named
customerInfo. When you perform structural transformations, the value of the variable remains the same, but the data type or position of the variable in the Document structure changes.
Value transformations.This type of transformation resolves differences in the way values are expressed (for example, when systems use different notations for values such as standard codes, units of currency, dates, or weights and measures). When you perform value transformations, the name and position of the variable remain the same, but the data contained in the variable changes. For example, you can change the format of a date, concatenate two Strings, or add the values of two variables together.
When you build flow services or convert between document formats, you may need to perform one, two, or all of the above types of data transformation. The webMethods flow language provides two ways for you to accomplish data transformations between services and document formats in the pipeline: you can map variables to each other (create links) or you can insert transformers, which are services invoked within a MAP step.