Restrictions and limitations
This XML File Connection supports version 1.0 of the XML specification (Extensible Markup Language, W3C Recommendation 10-February-1998). Any well-formed XML file - including those with a prolog - will be accepted. Currently the following restrictions and/or limitations apply to the ITP XML File Connection:
- Only UTF-8, UTF-16, ASCII, and ISO-8859-1 encoded XML files are supported. Conforming to the XML specification, ASCII and ISO-8859-1 encoded files need a prolog that specifies their encoding or you need to specify a default encoding in the dm.ini file.
- ITP only supports replacement of character references (i.e., characters referenced by means of their numerical code) and the five predefined entity references (amp, lt, gt, apos, and quot). It does not support user-defined entities, and in particular it does not support externally defined entities. These will not lead to an error but simply will not be replaced.
- Tag attributes are not interpreted. In particular ITP currently does not support the XML:LANG attribute. Note that one can still dynamically change locale settings within a single XML file by specifying different locale settings in Dm.ini for different DID modules.
- ITP will perform a thorough check on the well-formedness of the XML input, but only if this input actually gets used in the model. Unused XML data will only be checked in a limited way. In particular, this holds for tag attributes and user defined entities, as these are currently ignored. The actual structure of the file - including proper nesting of tags - will always be checked. This means that the XML file connection may accept files that are not well-formed, but only if the model does not use the erroneous data.
- ITP will match tags based on their namespaces, but only if the DID module has been configured with namespace support. If the DID module does not specify namespaces tags are matched including the literal namespace prefix.
- One can only specify ASCII tags in the DID. Consequently, data with non-ASCII tags cannot be retrieved from the XML file.