dtdValidElement function

Determines whether an XML tag is valid within another.

This tests whether name is a legitimate tag to use as a direct sub-element of the within tag according to the definition of the within

element in the specified DTD.

dtdValidElement(name, within, dtd, pos=NULL)

Arguments

• name: The name of the tag which is to be inserted inside the within tag.
• within: The name of the parent tag the definition of which we are checking to determine if it contains name.
• dtd: The DTD in which the elements name and within are defined.
• pos: An optional position at which we might add the name element inside within. If this is specified, we have a stricter test that accounds for sequences in which elements must appear in order. These are comma-separated entries in the element definition.

Details

This applies to direct sub-elements or children of the within tag and not tags nested within children of that tag, i.e. descendants.

Returns

Returns a logical value. TRUE indicates that a name element can be used inside a within element. FALSE indicates that it cannot.

References

https://www.w3.org/XML/, http://www.jclark.com/xml/, https://www.omegahat.net

Author(s)

Duncan Temple Lang

See Also

parseDTD, dtdElement, dtdElementValidEntry,

Examples

dtdFile <- system.file("exampleData", "foo.dtd", package="XML")
 foo.dtd <- parseDTD(dtdFile)

  # The following are true.
 dtdValidElement("variable","variables", dtd = foo.dtd)
 dtdValidElement("record","dataset", dtd = foo.dtd)

  # This is false.
 dtdValidElement("variable","dataset", dtd = foo.dtd)