This example explains how more than one VEC file can be packaged together with external documents, for example symbols of the specified components. In this case the VEC shall be packed within an archive together with the external documents (according to the current published VEC recommendation) and an index file has to be provided.
The upper half of the diagram illustrates the file structure within the archive. In the root there is a 'index.vec' file that describes the content of the archive. The simplified content of this index file is illustrated in the lower half of the diagram.
For the example, the archive consists of following files:
In the VEC (especially in the index.vec) a DocumentVersion object is created for each external document (see lower half of the diagram). This DocumentVersion object references the PartVersion to which it is related. Beside all meta information about the document, the attribute dataFormat of the DocumentVersion specifies the format of the external document as a MIME-Type. The attribute fileName is a path relative to VEC-File pointing to the external document in the archive
The usage of file-based installation instructions is quite similar to the described approach for external documents. The FileBasedInstruction defines a pointer to the file packaged together with the VEC-file in the container and is referenced by the PartOccurrence.
The same effect could be achieved if a DocumentBasedInstruction is used, pointing to an external document (defined as described in the section before).
Important: The difference between the two approaches is that for the DocumentBasedInstruction a DocumentVersion is required. This means that the external file must be an official document with a document number, an appropriate versioning and so on. The FileBasedInstruction can point to any file needed. It is not a valid approach to use the FileBasedInstruction, if the external file is a valid document.
The Diagram shows a simple example for the usage of the external mapping mechanism. The elements highlighted in yellow represent the actual information described by this VEC instance. The elements highlighted in blue are defining the concrete mapping and the DocumentVersion highlighted in green represents the link to the mapped document (in this case a SVG-symbol).
The ExternalMapping element in this example defines that a representation of the referenced ConnectorHousingSpecification can be found in the SVG-symbol under the key “ID_27101123”.
The actual content data of the VEC-file (highlighted in yellow) and the mapping information is separated into two different DocumentVersion elements. This means even though both information are contained in the same VEC-file, from the perspective of a versioning mechanism they are clearly separated.