Some thoughts about subsetting the DFDL spec to make it more consumable for readers and implementors.

We need to decide how the use of a subset is indicated in a DFDL xsd. It can be implicit by the properties referenced, or explicit up front. The difference is best illustrated by an example. Let's say Bidi support is a subset and I don't want to use Bidi. If using the implicit method, then I still need the dfdl:textBidi property to be set to 'no' even when in subset mode because the same xsd could be used by a full DFDL processor and it will expect a value. If using explicit, then I don't need to set the dfdl:textBidi property at all, because the DFDL processor will never look for it unless the xsd is switched to include that subset.

Here's a straw man for some subsets.

Regards

Steve Hanson
Strategy, Common Transformation & DFDL
Co-Chair, OGF DFDL WG
IBM SWG, Hursley, UK,
smh@uk.ibm.com,
tel +44-(0)1962-815848

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