Element Declarations
<! ELEMENT SAMPLE (#PCDATA)>
Document Type Declarations
<!DOCTYPE name_of_root_element SYSTEM "URL" [ internal DTD subset]>
external DTD subsets: Link to an outside file( often *.dtd)
internal DTD subsets: declaration in the XML file
Command-line validation
libxml2
Wed-based validation
www.cogsci.ed.ac.uk/~richard/xml-check.html
www.stg.brown.edu/service/xmlvalid
Elements Declarations
- Define elements, like
<!ELEMENT SAMPLE1 ANY>
- Find out the #PCDATA, change all necessary elements to #PCDATA, like
<!ELEMENT SAMPLE2 (#PCDATA)>
- Find out the child elements, add to necessary elements, like
<!ELEMENT SAMPLE3 (CHILD_SAMPLE1+, CHILD_SAMPLE2?, (CHILD_SAMPLE3* | CHILD_SAMPLE4| CHILD_SAMPLE5)?,(CHILD_SAMPLE6, CHILD_SAMPLE7)*, #PCDATA )>
Comments in DTD, like <!-- comments -->
Tips:
Case sensitive
Sequence sensitive
Attribute Declarations
<!ATTLIST Element_name Attribute_name Type Default_value>
Attribute Types: CDATA, Emumerated, ID, IDREF, IDREFS, ENTITY, ENTINITYS, NMTOKEN, NMTOKENS, NOTION
<!ELEMENT AUTHOR EMPTY>
<!ATTLIST AUTHOR COMPANY CDATA #FIXED "TIC">
<!ATTLIST EXTENSION CDATA #IMPLIED>
<!ATTLIST AUTHOR NAME CDATA #REQUIRED>
<!ATTLIST AUTHOR COMPANY CDATA #FIXED "TIC">
<!ATTLIST EXTENSION CDATA #IMPLIED>
<!ATTLIST AUTHOR NAME CDATA #REQUIRED>
Namespaces
Everyone can define elements, so name collision can be avoided. Like java, to avoid the class name collision, import Name Space.
All from 《XML 1.1 Bible 3rd Edition》