Daffodil provides extensions to the DFDL specification. These properties are in the namespace defined by the URI urn:ogf:dfdl:2013:imp:opensource.ncsa.illinois.edu:2012:ext
. To use these the Daffodil DFDL Extensions, bind this namespace to the daf
prefix, like so:
Code Block | ||
---|---|---|
| ||
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:dfdl="http://www.ogf.org/dfdl/dfdl-1.0/"
xmlns:daf="urn:ogf:dfdl:2013:imp:opensource.ncsa.illinois.edu:2012:ext"> |
The following symbols defined in this namespace are described below.
...
A function that can be used in DFDL expressions. This functions does not return a value or accept any arguments. When called, it causes a Parse Error or Unparse Error.d
...
A property applied to simple and complex elements, which specifies whether the element supports only parsing, only unparsing, or both parsing and unparse. Valid values for this property are "parse"
, "unparse"
, or "both"
. This allows one to leave off properties properties that are required for only parse or only unparse, such as dfdl:outputValueCalc or dfdl:outputNewLine, so that one may have a valid schema if only a subset of functionality is needed.
All elements must have a compatible parseUnparsePolicy with the compilation parseUnparsePolicy (which defined by the root element daf:parseUnparsePolicy and/or the Daffodil parseUnparsePolicy tunable) or it is a Schema Definition Error. An element is defined to have a compatible parseUnparsePolicy with if it has the same value as the compilation parseUnparsePolicy or if it has the value "both".
...