2. What is XML?
• stands for “eXtensible Markup Language”
• is a language for documents containing structured information
• structured information – contains both content (words,
pictures, etc.) and some indication of what role that content
plays
• XML vs. HTML: XML was designed to transport and store
data. HTML was designed to display data.
3. Tags?! What are those?
<?xml version= “1.0”?>
<example>
<quote type=“movie”>The dude abides.</quote>
</example>
4. More info
<?xml version= “1.0”?>
<example>
<quote>The dude abides.</quote>
</example>
F. I. L. O.
First
In
Last
Out
5. We’ve got the M, Let’s return to the X
X stands for “extensible” in XML – remember?
• Extensible means there is NO predefined tag set
• XML is pretty general, in that it allows users to define their
own tags and the relationships between them
6. DTDs Make Rules for Tags
• Without rules, your document and tags will be worthless to others
• Rules are set with a DTD
DTD = Document Type Definition
Your DTD defines all kinds of things!
• what tags can be nested inside of other tags
• what kind of information can be stored inside certain tags
7. Sample DTD #1
<?xml version =“1.0” encoding=“US-ASCII”?>… Parent and Child Elements
our XML declaration statement ¡ Child elements are the only ones that can be
nested inside of Parent elements
¡ An example of DTD’s rule making abilities!
<!DOCTYPE customerorder [
Parent = Customer
<!ELEMENT Customer (Name, Email)> ¡ Children =
<!ELEMENT Name (#PCDATA)> ÷ Name
<!ELEMENT Email (#PCDATA)> ÷ Email
<!ELEMENT Physical Address (street, unit#*,
city, state, zipcode)>
<!ELEMENT street (#PCDATA)>
<!ELEMENT unit# (#PCDATA)>
<!ELEMENT city (#PCDATA)>
<!ELEMENT state (#PCDATA)>
<!ELEMENT zipcode (#PCDATA)>
<!ELEMENT Shipment (ShipDate, ShipMode)>
<!ELEMENT ShipDate (#PCDATA)>
<!ELEMENT ShipMode (#PCDATA)>
]>
8. Sample DTD #2
<!DOCTYPE TVSCHEDULE [
<!ELEMENT TVSCHEDULE (CHANNEL+)>
<!ELEMENT CHANNEL (BANNER,DAY+)>
<!ELEMENT BANNER (#PCDATA)>
<!ELEMENT DAY (DATE,(HOLIDAY | PROGRAMSLOT+)+)>
<!ELEMENT HOLIDAY (#PCDATA)>
<!ELEMENT DATE (#PCDATA)>
<!ELEMENT PROGRAMSLOT (TIME,TITLE,DESCRIPTION?)>
<!ELEMENT TIME (#PCDATA)>
<!ELEMENT TITLE (#PCDATA)>
<!ELEMENT DESCRIPTION (#PCDATA)>
<!ATTLIST TVSCHEDULE NAME CDATA #REQUIRED>
<!ATTLIST CHANNEL CHAN CDATA #REQUIRED>
<!ATTLIST PROGRAMSLOT VTR CDATA #IMPLIED>
<!ATTLIST TITLE RATING CDATA #IMPLIED>
<!ATTLIST TITLE LANGUAGE CDATA #IMPLIED>
]>
9. Element Type Declarations
Element Type Declaration Definition
EMPTY No content allowed
ANY Any content allowed
a,b Specific order (a, followed by b)
X|Y Either/or (X or Y)
a,b,(X|Y) Groups (a, then b, then X or Y)
* Zero or more elements allowed
+ One or more elements allowed
? Zero or one element allowed
One and only one allowed
#PCDATA Parsed character data
10. Sample DTD #2 (again)
<!DOCTYPE TVSCHEDULE [
<!ELEMENT TVSCHEDULE (CHANNEL+)>
<!ELEMENT CHANNEL (BANNER,DAY+)>
<!ELEMENT BANNER (#PCDATA)>
<!ELEMENT DAY (DATE,(HOLIDAY | PROGRAMSLOT+)+)>
<!ELEMENT HOLIDAY (#PCDATA)>
<!ELEMENT DATE (#PCDATA)>
<!ELEMENT PROGRAMSLOT (TIME,TITLE,DESCRIPTION?)>
<!ELEMENT TIME (#PCDATA)>
<!ELEMENT TITLE (#PCDATA)>
<!ELEMENT DESCRIPTION (#PCDATA)>
<!ATTLIST TVSCHEDULE NAME CDATA #REQUIRED>
<!ATTLIST CHANNEL CHAN CDATA #REQUIRED>
<!ATTLIST PROGRAMSLOT VTR CDATA #IMPLIED>
<!ATTLIST TITLE RATING CDATA #IMPLIED>
<!ATTLIST TITLE LANGUAGE CDATA #IMPLIED>
]>
11. Attribute List
Attribute example in XML:
<example>
<quote type=“movie”>The dude abides.</quote>
</example>
Attribute example defined in DTD:
<!ELEMENT quote (#PCDATA)>
<!ATTLIST quote type CDATA #REQUIRED>
12. Now let’s try doing it!
http://tinyurl.com/3r5o9y2
1. Download two files to your
desktop
2. Save them in a new folder
called “xml_practice”
3. Open them in Oxygen
14. Applying XML
EAD!
• stands for Encoded Archival Description
• is a XSD (but all the rules are already made for you!)
• started in 1993 as part of The Berkeley Project at the Univ. of California –
Berkeley
• based on commonalities between finding aids sent in by archivists around the
world
• The prototype of EAD was released on February 26,1996!
• Today the official EAD standards are maintained by The Library of Congress
and the Society of American Archivists.
• If you’re in Archival Enterprise I and have any questions about the EAD
assignment, feel free to come to the lab and ask us questions!
http://www.loc.gov/ead/
http://www.archivists.org/saagroups/ead/
15. Applying XML (cont’d)
There are hundreds, but just to name a few…
• XHTML http://www.w3.org/TR/xhtml1/
• CML http://www.xml-cml.org/
• WML http://www.openmobilealliance.org/Technical/wapindex.aspx
• ThML http://www.ccel.org/ThML/
• WebML http://webml.org/webml/page1.do
• LegalXML http://www.legalxml.org/committees/index.shtml
• Text Encoding Initiative (TEI): http://www.tei-c.org/index.xml
16. Resources
• http://www.w3.org/XML/
• http://www.w3schools.com/xml/default.asp
• http://www.w3schools.com/dtd/default.asp
• http://www.tizag.com/xmlTutorial/
• http://www.loc.gov/ead/
• http://www.archivists.org/saagroups/ead/
• XML syntax validator:
http://www.w3schools.com/xml/xml_validator.asp
• More about ATTLIST:
http://www.w3schools.com/dtd/dtd_attributes.asp
