XML DTDLesson 78Free preview

DTD Attributes

This lesson is part of XML · All levels

Summary

The DTD attribute is declared with <!ATTLIST>, complete with the attribute name, its data type, and its presence rules. The presence rule is #REQUIRED (obligatory), #IMPLIED (optional), #FIXED "value" (locked), or value default. Types available include CDATA, ID, IDREF, NMTOKEN, enumeration, as well as entity and notation types.

Key points

Basic form: <!ATTLIST element attribute rule type>
#REQUIRED = must be filled; #IMPLIED = may be empty
"red" = always use that value (#FIXED)
ID = unique value; IDREF refers to other IDs; IDREFS for many references
The enumeration limits options such as ("work day" at "weekend")

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