???????? ? ObjectXPathNavigator

1
???????? ? ObjectXPathNavigator

• ??????????
• ???????
• ???????????

2
??????????

• ???????? ??? ?????? ???????? ? ??????
• ??????????? ?? ?????? ????? ?????? ? ????????
  ?????.
• ????????????? ??????????? ?????? XML-?????.
• ??????? ?????? ???????? ????? XPath.
• ????????????? ????? ???????? ???
  XSLT-?????????????.

3
???????

• XPath Querying Over Objects with
  ObjectXPathNavigator
• ?????? ? MSDN March 2003. Steve Saxon, Dell
  Computer Corporation.
• JXPath
• ??????? ????????????? XPath ????? ???? ????????
  ? ??????? ?????? ????????.
• ????????? ????????? XPath-??????? ? ????????
  ?????????.
• ????????????, ????????, ????????? ? Prevayler.
• Prevayler
• ??????? ?? ????????? ????????, ??????????????
  ?????????? ? ?????????? ??????? ???-????????
  (POJO).
• ???? ??????????? - ?????? 2.3 (????) ???????? 7
  ???? 2006.
• Bamboo.Prevalence
• ?????? Prevayler ??? .NET.
• ???????? XPathObjectNavigator (?????? JXPath).

4
?????????? ?????? ??????? ??? .NET

• ????????????? ????????? ?????? XML
• ?? ??????????? ???????
• XmlSerializer
• ? ???????? ????????? ????????? ??????.
• ?? XmlSerializer ??????? ??????????? ??? ? XML, ?
  ?????? ????? ?????? ??? ??????????.

5
?????????????
?????????? ?????????????
ObjectXPathContext context new
ObjectXPathContext() XPathNavigator nav
context.CreateNavigator( o )
??????????? ???????????? ????
ObjectXPathContext context new
ObjectXPathContext( nsmgr ) context.NamespaceMana
ger.AddNamespace( "sdf", Namespaces.SDF
) XPathNavigator nav context.CreateNavigator(
o )
6
?????????????
??????????? ??????????? ???????? ? ??????????
ObjectXPathContext context new
ObjectXPathContext( nsmgr ) context.RegisterNode
Policy( typeof( INullableType ), typeof(
NullableNodePolicy ) ) context.ConverterFactory.
AddConverter( typeof( NullableDateTime ), new
NullableDateTimeConverter() ) XPathNavigator
nav context.CreateNavigator( o )
7
???????? ????????
??? ???????? ?????? ??????????
???????? XML ????
XmlRoot( "product", NamespaceNamespaces.SDF
) public class Product XmlAttribute( "id"
) public int ProductId get ... set ...
XmlAttribute( "name" ) public string
Field1 get ... set ... XmlElement(
"description" ) public string Description get
... set ... XmlElement( "Date",
FormXmlSchemaForm.Unqualified ) Converter(
typeof( SimpleConverter )) public DateTime
Date get ... set ... XmlAnyElement
public XmlElement Xml get ... set ...
ltsdfproduct id"123" name"Red button"
xmlnssdf"..."gt ltsdfdescriptiongt Red
button description lt/sdfdescriptiongt ltDategt10.
10.2006lt/Dategt ... lt/sdfproductgt
8
???????????

• ObjectXPathNavigator ??????????? ?????
• ????????? ? ?????? XPathNavigator.
• ???????????? ???????? ?? ?????? ????? (?????????,
  ?????????).
• ?????? ??????????? ????????? ?? ???? ?????? ??
  ????????.
• ????????? ????????? ??????????.
• ???? ?????? ???????? ? ???? ??????????? ??????
  Node.
• Node
• ?????????? ?????? XmlNode.
• ????????? ????????? ??????? ??? ????? ?????
  ?????????.
• ????????? ????????? ???????? ????????, ????? ???
  ??????? ?????????.

9
???????????

• NodePolicy ????????
• ???????? ???????? ?? ????????? ???? ????????.
• ????????????? ???????? Policy (Strategy).
• ???????? ??????????.
• ????????? ?????? ????????? ????? ?? ????.
• ????????? ??????????? ????????
• GenericNodePolicy. ??????????? ???????? ????????
  ??????? ? ???????? ? ????????.
• MemberNodePolicy ??????????? ????, ????????
  ??????? ??? ?? ?????????? ???????????.
• TextNodePolicy ??????????? ???? ???? ???????,
  ??????????? ? ????? ? ???????? ??????????.
• ListNodePolicy ????????? ???????????? ??
  ??????????? ????????, ??????????? ?????????
  IList.

10
???????????

• ??????????
• ? XML-?????? ????????? ????? ????? ???????
  ?????????????? ? ???? ???????? ??????.
• ?????????? ??????????? ???????? ????? ? ?????.
• ????? ?????? ????? ?????????? ? ?????????????? ??
  
• ????????? ??????????? ??????????
• GenericConverter ?????? ?????????? ToString().
• BooleanConverter, DateTimeConverter,
  DoubleConverter ? ?.?. ??????????? ????????? ?
  ??? ??????, ??????? ?????? ??? XML.
• EnumConverter ??????????? ???????? ? ????????,
  ??? ??? ?????? ? ????.

11
?????????? ????
????????, ??? ??????

• ?????????? ???? ?????? ?????????? ?????? XML.
• ????????? ?? ??????????????? ?? ?????????? ????
• ??????? ???? ??????????
• ??????? Transparent(true).
• ????? GetIsTransparent.
• ????????? ???? ???????? ??????????? ???
  ???????????? ???????? ?????? XmlSerializer.

public class Person string Name string
Alias
??????? XML
ltPersongt ltNamegtJohn Smithlt/Namegt ltAliasgt
ltstringgtJohnnylt/stringgt ltstringgtSmithylt/stri
nggt lt/Aliasgt lt/Persongt
? ???????? ?? ????????
ltpersongt ltnamegtJohn Smithlt/namegt
ltaliasgtJohnnylt/aliasgt ltaliasgtSmithylt/aliasgt
lt/persongt
12
?????????? ????? ???????
INodePolicy

• ???????? ????????? ????????? INodePolicy
• ?????? ????????????.
• GetNewPolicy ?????????? ??? ????????? ????????
  ???????.
• GetPolicy - ????? ??? ????????? ??????????
  ????????.
• ??????????? ????????
• ??????? NodePolicy ?? ???????? ??? ??????.
• ????? RegisterNodePolicy (??? ???????, ???
  ????????).
• ??? ??????? ????? ???? ???????????.
• ??????? NodePolicyGet.

public interface INodePolicy INodePolicy
GetNewPolicy( Node node ) string GetName( Node
node ) string GetNamespace( Node node
) XPathNodeType GetNodeType( Node node
) string GetValue( Node node ) bool
GetIsTransparent( Node node ) int
GetAttributesCount( Node node ) Node
GetAttribute( Node node, int index ) int
FindAttribute( Node node, string name, string ns
) int GetChildrenCount( Node node ) Node
GetChild( Node node, int index )
public static new INodePolicy GetPolicy() ...
13
?????????? ????? ???????????
IConverter

• ????????? ????????? ????????? IConverter
• ToString - ??????????? ???????? ??????? ? ?????.
• ParseString ? ?????? ?????? ?? ????????????.
• ??????????? ??????????
• ??????? Converter ?? ???????? ??? ??????.
• ????????? ????? AddConverter.

public interface IConverter string ToString(
object obj ) object ParseString( string str )
14
????????? ?????????

• ?????? ????????????? ?? ???????????
  ??????????????.
• ??????????? ?????? ??????.
• ?????????? ?????? ????? ?????????.
• ?????????? ?????.
• ?????????????? ????????????.
• ? ?.?.

15
??????????

• ???????? MIT-style.
• ??????? ?????? ?? ????? ?????http//blogs.byte-f
  orce.com/files/12/objectxpathnavigator/default.asp
  x
• ????? ?? ???????? http//blogs.byte-force.com/fo
  rums/28/ShowForum.aspx