Converting WSDL to the Target Language (SAP Library - SAP Exchange Infrastructure (BC-XI))

Converting WSDL to the Target Language

As illustrated in the graphic below, a WSDL document converted by proxy generation comprises two parts, namely a description of data types and an interface description, the parameters of which are used by these data types:

This graphic is explained in the accompanying text

The proxy generation functions fetch the WSDL description from the Integration Repository and convert it to proxies:

The WSDL elements of the interface description are converted on a 1:1 basis into objects of the respective target language (classes, interfaces, methods).
The conversion of the data types to XSD (XML Schema Definition Language) can be subject to restrictions, depending on the target language (see below).

The WSDL description contains, among other things, the structure of a message. The message that is then sent using the Exchange Infrastructure therefore corresponds to an instance of this description (also see: Messages).

Also see:

ABAP Proxy Generation

Java Proxy Generation

Data Type Generation

Data types from the Integration Repository are described using XSD. You can also define your data types with XSD tags in the XSD editor of the interface maintenance. Although you can only select tags in the XSD editor that you can convert to the target language, there can be additional restrictions as well as those in the XSD editor. For a description of these restrictions, see the attachments in the respective sections (Attachment: Mapping XSD to ABAP or Attachment: Mapping XSD to Java). The following section is a brief introduction to XSD.

XSD: Brief Introduction

The following XSD data types exist:

XSD provides numerous in-built data types (for example xsd:decimal) and defines a clearly defined value range. You can use them globally. Many of these data types cannot be mapped exactly to ABAP data types because the value ranges do not match. In cases such as these, you must check yourself whether a received value is within the value range of the data type in the respective target language.

You can reconstruct new data types from in-built data types using the tag <simpleType>. For example, you can define a pattern for xsd:string for telephone numbers. The Proxy Framework does not check this type of enhancement because they are checked when the system validates an XML document.

You can then define structured data types using the tag <complexType>. Elements that are located between this and the corresponding closing tag are local and you can only access them using the upper-level type. Instead of this nesting, for complexType tags you can link to other structured or simple data types.

Use the tag <element> to then define the elements that can occur in the XML schema and use <attribute> to define the attributes of these elements. You can then use the XSD data types to assign types. Definitions with <element>, <attribute>, <simpleType>, and <complexType> are visible globally if the subnodes of the top-level node are <schema>. You can only use nested types, elements, or attributes locally.

Note

For an overview of XSD see http://www.topxml.com/xml/articles/xsd/kurt_schema2.asp. The official W3C recommendation from May 2, 2001 comprises three parts: XML Schema Part 0: Primer, XML Schema Part 1: Structures and XML Schema Part 2: Data Types.