Cart
[Home] [By Thread] [By Date] [Recent Entries]
At 10:44 AM 10/23/2005, you wrote: Basically, I would like to develop schemas that impose >>>constraints on an element or attribute in one XML file based on >>>element or attribute values from another XML file. Is this at >>>all possible? I would consider making a file containing just a >>>list of all available item IDs, if that would help solve the >>>problem. > >Theoretically, I think this could do the trick: > > (1) Include the XML document that contains IDs into the document that > refers to them via a parsed external entity [XML Rec, 4.2.2, 4.3] > > (2) Use WXS key/keyref feature [WXS, Part 1, 3.11] to encode your > referential constraints. > >(1) will physically keep the data in separate files, but the processor >should pull them together, so the schema (2) could be written as if the >data was present in a single file. Let me see if I understand. The external entity could look like this: <item id="abc123"/> <item id="def456"/> ... Then in some other XML document the DTD will include these lines: <!ATTLIST item id ID #REQUIRED> <!ENTITY itemlist SYSTEM "itemlist.xml"> and later in the body of the document: <items>&itemlist;</items> Something like this? But if I am already using a DTD to describe my document, can I use a schema as well?
|
