XML Information

General Tech

MapInfo / GIS

Oracle / Database

Misc / Useless

XML Information

XML Declaration Information

example: <?xml version="1.0" standalone="yes" encoding="ISO-8859-1"?>
version="" - value must be 1.0
standalone="" - a no value signals the parser that it should import other mark-up files, such as an external DTD
encoding="" - ISO-8859-1 is the default and is essentially the English character set

XSL/XSLT (XSL Transformations) Information

click here for info on XSL/XSLT

Document Type Declaration Information

it's a DOCTYPE processing instruction that goes into the prologue of a well-formed XML document, declaring the type of document - the root element serves as the name of the document type
to include the DTD within the XML document, the processing instruction would read:
<!DOCTYPE library [
. . . DTD goes in here . . .
]>
the DOCTYPE declaration to reference an external .dtd file (external subset) takes on the form:
<!DOCTYPE type(root element) SYSTEM "common.dtd">
<!DOCTYPE AddressBook SYSTEM "http://www.myserver.com/xml/address.dtd">
<!DOCTYPE Customer SYSTEM "file:/D:/JOHN/xmltips/test/common.dtd">
or
<!DOCTYPE type(root element) PUBLIC "DTD name" "DTD url">

DTD (document type definition) Syntax Information

element decalaration: <!ELEMENT elementName elementContents>
element contents:
(other elements) - nested elements listed within parentheses
- , - contents in () must occur in succession
- | - indicates an or relationship, it's a choice modifier, it allows you to specify a list of choices, for example: <!ELEMENT Sport (Football | Baseball | Basketball)> , so sport must contain one (and only one) of the tags in the choice list
ANY - indicates that any content is allowed
EMPTY - element has no content
(#PCDATA) - parseable character data
indicate # of times element may appear:
(no indicator) - element must appear once and only once
? - indictates optional element
+ - indictates element may be repeated more than once but must occur at least once
* - indicates that the content is optional (may occur zero or more times)
element's attribute list must be defined outside the element declaration; each with its own declaration
attribute declaration: <!ATTLIST elementName attributeName type default>
attribute types:
CDATA - character data, any text is allowed, values are not parsed like PCDATA (don't want to be mistaken for markup), i.e. <![CDATA['your stuff here']]>
(list of possible values) - i.e. (left|right|center)
ID - must be a unique name (must begin with one of the NAMESTRT (generally letter-like characters)
IDREF/IDREFS - value must be the value of a single ID attribute on some element in the document
ENTITY/ENTITIES - value must be the name of a single entity
NMTOKEN/NMTOKENS - a restricted form of string attribute
attribute defaults:
#REQUIRED - must have an explicitly specified value on every occurrence of the element in the document
#IMPLIED - value is not required, and no default value is provided
'value' - can be given any legal value as a default
#FIXED "value" - must have the specified value
XML macros
define a general entity in a DTD
<!ENTITY byline "by John Doe, (c) 1996">
reference it in your XML document
<Author> &byline;</Author>

or define a parameter entity in a DTD
<!ENTITY % dataid "dbid CDATA #REQUIRED">
reference it in your XML document
<!ATTLIST person %dataid;
name CDATA #REQUIRED
address CDATA #REQUIRED>
XML processing instructions (PIs) - example:
<? target ...instruction... ?>
<?xml version="1.0" encoding="UTF-8" standalone="y" ?>
character references - they start with &#x followed by the hexadecimal character code, or &# followed by the decimal character code - example:
<copyright>© 2000 My Company , all rights reserved.</copyright>
notations are a way to associate a name with an external application
<!NOTATION bmp SYSTEM "paint.exe">
<!NOTATION gif SYSTEM "gif.exe">
<!ATTLIST img type NOTATION (bmp|gif) "bmp" >

Example VB Information

to open and read code:
Set xmlDoc = New MSXML.XMLDocument
xmlDoc.URL = sFile

Example DTDs/Schemas

<!ELEMENT housePlan (floorPlan+, elevation+, crossSection+)>
<!ELEMENT floorPlan EMPTY>
<!ATTLIST floorPlan
name ID #REQUIRED
URL CDATA #REQUIRED
>
<!ENTITY xml "Extensible Markup Language">
<!ELEMENT library (book+)>
<!ELEMENT book (title,(author|editor)+,publisher,year)>
<!ATTLIST book call_no CDATA #REQUIRED>
<!ELEMENT title (#PCDATA)>
<!ELEMENT author (last_name,first_name)>
<!ELEMENT editor (last_name,first_name)>
<!ELEMENT last_name (#PCDATA)>
<!ELEMENT first_name (#PCDATA)>
<!ELEMENT publisher (#PCDATA)>
<!ELEMENT year (#PCDATA)>
following example allows for countries with multiple land borders, countries with multiple ocean borders, and countries with a combination of the two:
<!ELEMENT country (
officialCountryName,
(
(borderingBodyOfWater+, borderingCountry+)
| (borderingCountry+)
| (borderingBodyOfWater+)
)
)>
for DTD:
<!DOCTYPE Name [
<!ELEMENT Name (First,Last)>
<!ELEMENT First (#PCDATA)>
<!ELEMENT Last (#PCDATA)>
]>

the XML schema would be:
<schema xmlns="http://www.w3.org/1999/XMLSchema">
<element name="Name" type="NameType"/>
<complexType name="NameType">
<element name="First" type="string"/>
<element name="Last" type="string"/>
</complexType>
</schema>

XML Feature Chart

Feature	Property Bag	ADO	Comma-Delimited Text File	XML
Text Based		X	X	X
Readable				X
Hierarchical structure				X
Maintained easily				X
Self-validating				X
Self-documenting				X
Accessible with a wide variety of tools				X
Parser provided	X	X		X
Object model provided	X	X		X
Standard format				X
Simple to program		X		X
Fast	N/A	N/A		X
Allows excluding empty values	X			X