Content: - Structures - Datatypes References: - Beginning XML, 5th Edition, Joe Fawcett, Liam R. E. Quin, Danny Ayers - XML in a nutshell,3rd Edition, Elliotte Rusty Harold & W. Scott Means - http://www.w3schools.com/

1. Validation – XML Schemas
Nguyễn Đăng Khoa

2. Content
• Document Type Definitions (DTDs)
• XML Schemas

3. XML Schemas (XSD)
• Define XML vocabularies and grammars
• Describe the structure and content of XML
documents in more detail than DTDs
• XML Schema 1.0 specifications were first
published by the W3C in 2001, with a second
edition following in 2004
• XML Schema 1.1 became a W3C
Recommendation in April 2012

4. XSD’s goals
• Check XML document is valid or not

5. XSD – Benefits
• Are created using basic XML
• Fully support the Namespace Recommendation
• Validate text element content based on built-in
and user-defined data types
• Create complex and reusable content models
• Enable the modeling of programming concepts
such as object inheritance and type substitution

6. XSD 1.0 - Specifications
• Part 1: Structures
(http://www.w3.org/TR/xmlschema-1/)
• Part 2: Datatypes
(http://www.w3.org/TR/xmlschema-2/)

7. XSD - Example

8. XSD – Namespace in XSD & XML

9. XSD – Explicitly namespace

10. XSD – Default namespace

11. XSD – XML doesn’t use namespace
URI to xsd

12. XSD – XML uses namespace

13. XSD – XML uses namespace
URI to xsdnamespace blank

14. XSD – XML uses namespace

15. XSD – XML uses namespace

16. XSD – Element and Attribute
qualification

17. XSD – qualified vs. unqualified
qualified
unqualified

18. XSD – Global vs. Local
Global
Local

19. XSD – Global vs. Local
• Global declarations are declarations that
appear as direct children of the <schema>
element. Global element declarations can be
reused throughout the XML Schema.
• Local declarations do not have the <schema>
element as their direct parent and can be
used only in their specific context.

20. XSD – elementFormDefault
• qualified: nested elements must belong to the
target namespace of the schema
• unqualified is default value, a mix of qualified
and unqualified elements

21. XSD – elementFormDefault – Example
Valid

22. XSD – elementFormDefault – Example
Invalid
Element 'first': This element is not expected. Expected is ({http://www.example.com/name}first)

23. XSD – elementFormDefault – Example
Valid

24. XSD – elementFormDefault – Example
Invalid
Element '{http://www.example.com/name}first': This element is not expected. Expected is (first)

25. XSD – attributeFormDefault – Example
• Is same elementFormDefault
• unqualified is default value

26. XSD – attributeFormDefault – Example
Valid

27. XSD – attributeFormDefault – Example
Invalid

28. XSD – attributeFormDefault – Example
Invalid

29. XSD – Content Models
• Is allowable content (type) of elements and
attributes
• There are 2 content models
– <complexType>
– <simpleType>

30. XSD - <complexType>
• Defines types that contain attributes or
elements
• There are 3 ways of interpreting a list of
elements
– <sequence>: Elements must appear in the given
order
– <choice>: Only one of the elements in the list may
appear
– <all>: Elements can appear in any order, with each
child element occurring zero or one time

31. XSD – <complexType> – Example

32. XSD – <complexType> – Example

33. XSD – Rule of <all>
• The <all> declaration must be the only content
model declaration that appears as a child of a
<complexType> definition
• The <all> declaration can contain only
<element> declarations as its children
– No <sequence>, <choice>, <group> in it
• The <all> declaration’s children may appear
once each in the instance document

34. XSD - <element>

35. XSD - <element> – Name

36. XSD - <element> – Type

37. XSD - <element> – Local Type
include the type
declaration as a child of
the element declaration

38. XSD - <element> – Global Type

39. XSD - <element> – Cardinality

40. XSD - <element> – Cardinality
Default: 1

41. XSD - <element> – Default value

42. XSD - <element> – Fixed value

43. XSD – Mixed Content
• Enable you to include both text and element
content within a single content model

44. XSD – Simple Content
• Enable you to include only text within a single
content model

45. XSD – Empty Content

46. XSD – Elements Wildcards
• Suppose you want to specify that your
element can contain any of the elements
declared in your namespace, or any elements
from another namespace

47. XSD – Elements Wildcards
List of namespace URIs

48. XSD – Elements Wildcards
indicate that any element from the schema’s target namespace can be
used

49. XSD – Elements Wildcards
indicate that elements not in any namespace can be used

50. XSD – Elements Wildcards
indicate that all elements from any namespace or no namespace are allowed

51. XSD – Elements Wildcards
indicate that elements from namespaces other than the schema’s
target namespace can be used

52. XSD – Elements Wildcards
(Default) Elements represented by this <any> element must be
declared. Furthermore, the element must be valid according to its
declaration

53. XSD – Elements Wildcards
Elements represented by this <any> element need not be declared in
the schema and need not be valid even if they are declared

54. XSD – Elements Wildcards
Elements represented by this <any> element must be validated if they
are declared, but must not be validated if they are declared

55. XSD – Elements Wildcards – Rules
• The <any> declaration can appear only within a content model.
• You are not allowed to create global <any> declarations

56. XSD – <group>
• Enable you to define reusable groups of
elements

57. XSD – Exercise - No namespace

58. XSD – Exercise – Use namespace

59. XSD - <attribute>

60. XSD - <attributeGroup>
• Enable you to define reusable groups of
attributes

61. XSD – Built-in Data Types

62. XSD – Built-in Data Types

63. XSD – Built-in Data Types

64. XSD – Built-in Data Types

65. XSD – Built-in Data Types

66. XSD – Built-in Data Types
• In addition to the types listed, the XML Schema
Recommendation also allows the types defined
within the XML Recommendation
– ID
– IDREF
– IDREFS
– ENTITY
– ENTITIES
– NOTATION
– NMTOKEN
– NMTOKENS

67. XSD – Exercise

68. XSD – User-Defined Data Types
• When you declare a <simpleType>, you must always
base your declaration on an existing data type
– Built-in
– Custom
• <simpleType> definitions are often called derived
types. There are three primary derived types:
– Restriction types
– List types
– Union types

69. XSD – User-Defined Data Types
prevent a simple type from being subtyped

70. XSD – Restriction Type
• is a subset of its base type
Facet

71. XSD – Restriction Type – Constraining
FacetsConstraint Description
enumeration Defines a list of acceptable values
fractionDigits Specifies the maximum number of decimal places allowed. Must be equal to or greater than zero
length Specifies the exact number of characters or list items allowed. Must be equal to or greater than zero
maxExclusive Specifies the upper bounds for numeric values (the value must be less than this value)
maxInclusive Specifies the upper bounds for numeric values (the value must be less than or equal to this value)
maxLength Specifies the maximum number of characters or list items allowed. Must be equal to or greater than zero
minExclusive Specifies the lower bounds for numeric values (the value must be greater than this value)
minInclusive Specifies the lower bounds for numeric values (the value must be greater than or equal to this value)
minLength Specifies the minimum number of characters or list items allowed. Must be equal to or greater than zero
pattern Defines the exact sequence of characters that are acceptable
totalDigits Specifies the exact number of digits allowed. Must be greater than zero
whiteSpace Specifies how white space (line feeds, tabs, spaces, and carriage returns) is handled
Ref: http://www.w3schools.com/schema/schema_facets.asp

72. XSD – List Type
• create a list of items

73. XSD – Union Type
• allow potential values for elements and
attributes to have any of several types

74. XSD – Union Type