XML
Rule - Opening and closing tag
All XML Elements must have opening and closing tag.
Rule - Nesting
All nested elements must be properly nested. A child element's opening and closing tags must be within the parent element's opening and closing tags.
Child element
An element nested within another element.
Rule - Attribute and value
Attributes must be in OPENING TAG, and must be in the form: name="value". The attribute value must be in quotes.
CSS
Cascading Style Sheet (CSS) is a language that can be used to describe the presentation of XML elements.
XML Schema
Describe the structure of an XML document and defines the building blocks
Rule - Root Element
Every XML document must have a SINGLE root element that contains all other elements.
XML
Extensible Markup Language
XPATH
Extensible Path Language, used to extract data from an XML file.
XSL-FO
Extensible Stylesheet Language Formatting Objects is a language for formatting XML documents into PDF documents
XSLT
Extensible Stylesheet Language Transformations, a styling language that can transform XML file into another file type (HTML, PDF, MS Word, etc.)
Prolog
First line of the XML document, usually includes the XML declaration which defines the XML VERSION, and the document ENCODING.
XML vs HTML TAGs
HTML tags are pre-defined; XML tags are *not* pre-defined.
Rule - Special characters
Less than, greater than, ampersand, apostrophe, and quotation marks within an element must be specified differently. <, >, &, &apos, ".
Element
Piece of data in XML, bounded by a start and end tag. Elements may contain attributes, text, or child elements.
Attribute
Special information about an element that contains additional information about the element. Attributes are contained within the element's opening tag.
Root Element
The outermost element defined for the XML document.
Rule - Case sensitivity
XML tags *are* case senstitive.
XML vs HTML
XML used to STRUCTURE, DESCRIBE, and CARRY data; HTML is to DISPLAY data.
Benefits of having a schema
1. Better define, restrict, and convert specific data types. 2. Allows us to validate our data and ensure conformance to standard. 3. Encourages standardization. 4. Can be re-used.
Rule - Comments
<!-- This is a comment -->
XQUERY
Used to perform query functions on XML data, similar to SQL for databases
Rule - White space
White space within an XML element is preserved. <Name>Thomas E. Littlejohn</Name>
XSD
XML Schema Definition, a file that describes the structure of an XML document. Describes the valid format of an XML data set. Mandatory/optionality, cardinality, etc.
