Step 4: Creating the Mapping Between Input and Output Data Formats

Although the BizTalk Editor can structure the information into common formats such as X12 EDI or UN/EDIFACT that can be read and processed by the system that understands the standard formats, many times information is received and needs to be translated into a different format. This mapping of input and output fields ensures that the right information is relayed to the destination.

The BizTalk Mapper is the tool included with BizTalk Server that provides the mapping between fields.

BizTalk Mapper

BizTalk Mapper allows the definition and the correlation of data between records and fields for one document specification, and the records and fields for another. The mapping of information from one input format to another goes through one of two different processes. The BizTalk Server can alter the schema of the information in a process that is said to transform the information, or the BizTalk Server can actually alter the data itself in a process that is said to be a translation of the information.

The transformation process used by the BizTalk Server is handled by script coding using functoids. A functoid is a reusable function built-in to the server engine that enables simple as well as complex structural manipulation between source and destination specifications. A transformation of information is common because input and output formats frequently do not match and need to be mapped so that fields from one format match the fields of the other format during the transformation process. A transformation process, although by definition means that the data is altered, does not necessarily mean that the information is deleted and replaced with completely different data, but that information is analyzed and modified for a new or different format.

An example of data transformation could be the replacement of a State definition such as Calif with a standard two-letter CA postal format, or a data label may be padded with extra spaces to keep the data format the same length such as keeping a field to eight total characters even if that means that several characters are spaces. BizTalk Mapper uses extensible style sheet language (XSL) to process the map transformation.

As an XSL generator, the BizTalk Mapper allows for both simple one-to-one mappings and more complex mappings using functoids. The graphical mappings defined in the editor are compiled down to XSL to be applied by the BizTalk Server engine at runtime to the inbound document. Inbound documents are parsed into XML representation of the information using the specifications defined in the BizTalk Editor. If mapping is required, the XSL is applied, and the document is serialized into the correct outbound format by the messaging engine using the outbound BizTalk Editor-generated specification.