TOPIC
    about_Types.ps1xml

SHORT DESCRIPTION
    Explains how the Types.ps1xml files let you extend the Microsoft .NET 
    Framework types of the objects that are used in Windows PowerShell. 

LONG DESCRIPTION
    The Types.ps1xml file in the Windows PowerShell installation directory
    ($pshome) is an XML-based text file that lets you add properties and 
    methods to the objects that are used in Windows PowerShell. Windows 
    PowerShell has a built-in Types.ps1xml file that adds several elements
    to the .NET Framework types, but you can create additional Types.ps1xml
    files to further extend the types.

    For example, by default, array objects (System.Array) have a Length 
    property that lists the number of objects in the array. However, because
    the name "length" does not clearly describe the property, Windows 
    PowerShell adds an alias property named "Count" that displays the same 
    value. The following XML adds the Count property to the System.Array type.

        <Type>
            <Name>System.Array</Name>
            <Members>
                <AliasProperty>
                    <Name>Count</Name>
                    <ReferencedMemberName>
                        Length
                    </ReferencedMemberName>
                </AliasProperty>
            </Members>
        </Type>

    To get the new AliasProperty, use a Get-Member command on any array, as shown
    in the following example.

        Get-Member -inputobject (1,2,3,4)


    The command returns the following results.

	Name           MemberType    Definition
	----           ----------    ----------
	Count          AliasProperty Count = Length
	Address        Method        System.Object& Address(Int32 )
	Clone          Method        System.Object Clone()
	CopyTo         Method        System.Void CopyTo(Array array, Int32 index):
	Equals         Method        System.Boolean Equals(Object obj)
	Get            Method        System.Object Get(Int32 )
	...


    As a result, you can use either the Count property or the Length property 
    of arrays in Windows PowerShell. For example:

	C:\PS> (1, 2, 3, 4).count
	4

	C:\PS> (1, 2, 3, 4).length
	4
 

  Creating New Types.ps1xml Files

      The .ps1xml files that are installed with Windows PowerShell are 
      digitally signed to prevent tampering because the formatting can include
      script blocks. Therefore, to add a property or method to a .NET Framework
      type, create your own Types.ps1xml files, and then add them to your 
      Windows PowerShell console.

      To create a new file, start by copying an existing Types.ps1xml file. The
      new file can have any name, but it must have a .ps1xml file name 
      extension. You can place the new file in any directory that is accessible
      to Windows PowerShell, but it is useful to place the files in the Windows
      PowerShell installation directory ($pshome) or in a subdirectory of the 
      installation directory.

      When you have saved the new file, use the Update-TypeData cmdlet to add 
      the new file to your Windows PowerShell console. If you want your types
      to take precedence over the types that are defined in the built-in file,
      use the PrependData parameter of the Update-TypeData cmdlet. 
      Update-TypeData affects only the current console. To make the change to
      all future consoles, export the console, or add the Update-TypeData 
      command to your Windows PowerShell profile.


  Types.ps1xml and Add-Member

      The Types.ps1xml files add properties and methods to all the instances 
      of the objects of the specified .NET Framework type in the affected 
      Windows PowerShell console. However, if you need to add properties or 
      methods only to one instance of an object, use the Add-Member cmdlet.

      For more information,see Add-Member.


  Example: Adding an Age Member to FileInfo Objects

      This example shows how to add an Age property to file objects 
      (System.IO.FileInfo). The age of a file is the difference between
      its creation time and the current time in days.

      It is easiest to use the original Types.ps1xml file as a template
      for the new file. The following command copies the original file to
      a file called MyTypes.ps1xml in the $pshome directory.

          copy-item Types.ps1xml MyTypes.ps1xml


      Next, open the Types.ps1xml file in any XML or text editor, such
      as Notepad. Because the Age property is calculated by using a script
      block, find a <ScriptProperty> tag to use as a model for the new Age 
      property. 

      Copy the XML between the <Type> and </Type> tags of the code to create
      the script property. Then, delete the remainder of the file, except for 
      the opening <?xml> and <Types> tags and the closing </Types> tag. You 
      must also delete the digital signature to prevent errors.

      Begin with the model script property, such as the following script 
      property, which was copied from the original Types.ps1xml file.

          <?xml version="1.0" encoding="utf-8" ?>
          <Types>
              <Type>
                 <Name>System.Guid</Name>
                    <Members>
                        <ScriptProperty>
                            <Name>Guid</Name>
                            <GetScriptBlock>$this.ToString()</GetScriptBlock>
                        </ScriptProperty>
                    </Members>
              </Type>
          </Types>


      Then, change the name of the .NET Framework type, the name of the 
      property, and the value of the script block to create an Age property 
      for file objects.


          <?xml version="1.0" encoding="utf-8" ?>
          <Types>
              <Type>
                 <Name>System.IO.FileInfo</Name>
                    <Members>
                        <ScriptProperty>
                            <Name>Age</Name>
                            <GetScriptBlock>
                               ((get-date) - ($this.creationtime)).days
                            </GetScriptBlock>
                        </ScriptProperty>
                    </Members>
              </Type>
          </Types>


      After you save the file and close it, use an Update-TypeData command,
      such as the following command, to add the new Types.ps1xml file to the
      current console. The command uses the PrependData parameter to place the
      new file in a higher precedence order than the original file. (For more
      information about Update-TypeData, see Update-TypeData.)

          update-typedata -prependpath $pshome\MyTypes.ps1xml

      To test the change, use a Get-ChildItem command to get the 
      PowerShell.exe file in the $pshome directory, and then pipe the file to
      the Format-List cmdlet to list all of the properties of the file. As a 
      result of the change, the Age property appears in the list.

        get-childitem $pshome\powershell.exe | format-list -property *	


        PSPath            : Microsoft.PowerShell.Core\FileSystem::C:\WINDOWS...
        PSParentPath      : Microsoft.PowerShell.Core\FileSystem::C:\WINDOWS...
        PSChildName       : powershell.exe
        PSDrive           : C
        PSProvider        : Microsoft.PowerShell.Core\FileSystem
        PSIsContainer     : False
        Age               : 16
        VersionInfo       : File:             C:\WINDOWS\system32\WindowsPow...
                    InternalName:     POWERSHELL
                    OriginalFilename: PowerShell.EXE
	...


      You can also display the Age property of the file by using the following
      command.

	  (get-childitem $pshome\powershell.exe).age
          16
 

  The XML in Types.ps1xml Files

      The <Types> tag encloses all of the types that are defined in the file.
      There should be only one pair of <Types> tags.

      Each .NET Framework type mentioned in the file should be represented by 
      a pair of <Type> tags. 

      The type tags must contain the following tags:

          <Name>: A pair of <Name> tags that enclose the name of the affected 
                  .NET Framework type.

          <Members>: A pair of <Members> tags that enclose the tags for the 
                     new properties and methods that are defined for the
                     .NET Framework type.

      Any of the following member tags can be inside the <Members> tags.

      <AliasProperty>: Defines a new name for an existing property.

         The <AliasProperty> tag must have a pair of <Name> tags that specify
         the name of the new property and a pair of <ReferencedMemberName> tags
         that specify the existing property.       
            
         For example, the Count alias property is an alias for the Length     
         property of array objects.

             <Type>
                 <Name>System.Array</Name>
                 <Members>
                     <AliasProperty>
                         <Name>Count</Name>
                         <ReferencedMemberName>Length</ReferencedMemberName>
                     </AliasProperty>
                 </Members>
             </Type>


      <CodeMethod>:  References a static method of a .NET Framework class.

         The <CodeMethod> tag must have a pair of <Name> tags that specify
         the name of the new method and a pair of <GetCodeReference> tags
         that specify the code in which the method is defined.       
            
         For example, the Mode property of directories (System.IO.DirectoryInfo
         objects) is a code property defined in the Windows PowerShell 
         FileSystem provider.
        
             <Type>
                 <Name>System.IO.DirectoryInfo</Name>
                 <Members>
                     <CodeProperty>
                        <Name>Mode</Name>
                        <GetCodeReference>
                           <TypeName>Microsoft.PowerShell.Commands.FileSystemProvider</TypeName>
                           <MethodName>Mode</MethodName>
                        </GetCodeReference>
                     </CodeProperty>
                 </Members>
             </Type>

 
      <CodeProperty>: References a static method of a .NET Framework class.

         The <CodeProperty> tag must have a pair of <Name> tags that specify
         the name of the new property and a pair of <GetCodeReference> tags
         that specify the code in which the property is defined.       
            
         For example, the Mode property of directories (System.IO.DirectoryInfo
         objects) is a code property defined in the Windows PowerShell 
         FileSystem provider.
        
             <Type>
                 <Name>System.IO.DirectoryInfo</Name>
                 <Members>
                     <CodeProperty>
                        <Name>Mode</Name>
                        <GetCodeReference>
                           <TypeName>Microsoft.PowerShell.Commands.FileSystemProvider</TypeName>
                           <MethodName>Mode</MethodName>
                        </GetCodeReference>
                     </CodeProperty>
                 </Members>
             </Type>


      <MemberSet>: Defines a collection of members (properties and methods). 

         The <MemberSet> tags appear within the primary <Members> tags. The 
         tags must enclose a pair of <Name> tags surrounding the name of the
         member set and a pair of secondary <Members> tags that surround the 
         members (properties and methods) in the set. Any of the tags that 
         create a property (such as <NoteProperty> or <ScriptProperty>) or a
         method (such as <Method> or <ScriptMethod>) can be members of the set.

         In Types.ps1xml files, the <MemberSet> tag is used to define the 
         default views of the .NET Framework objects in Windows PowerShell. In
         this case, the name of the member set (the value within the <Name> 
         tags) is always "PsStandardMembers", and the names of the properties
         (the value of the <Name> tag) are one of the following:

	    - DefaultDisplayProperty: A single property of an object.

            - DefaultDisplayPropertySet: One or more properties of an object.

            - DefaultKeyPropertySet: One or more key properties of an object. 
              A key property identifies instances of property values, such as
              the ID number of items in a session history.

         For example, the following XML defines the default display of services
         (System.ServiceProcess.ServiceController objects) that are returned by
         the Get-Service cmdlet. It defines a member set named 
         "PsStandardMembers" that consists of a default property set with the 
         Status, Name, and DisplayName properties.

             <Type>
                <Name>System.ServiceProcess.ServiceController</Name>
                <Members>
                   <MemberSet>
                       <Name>PSStandardMembers</Name>
                       <Members>
                           <PropertySet>
                             <Name>DefaultDisplayPropertySet</Name>
                             <ReferencedProperties>
                                <Name>Status</Name>
                                <Name>Name</Name>
                                <Name>DisplayName</Name>
                             </ReferencedProperties>
                           </PropertySet>
                       </Members>
                   </MemberSet>
                </Members>
             </Type>

   
      <Method>: References a native method of the underlying object. 

      <Methods>: A collection of the methods of the object.

      <NoteProperty>: Defines a property with a static value.

         The <NoteProperty> tag must have a pair of <Name> tags that specify
         the name of the new property and a pair of <Value> tags that specify
         the value of the property.       
            
         For example, the following XML creates a Status property for 
         directories (System.IO.DirectoryInfo objects). The value of the 
         Status property is always "Success".

             <Type>
                 <Name>System.IO.DirectoryInfo</Name>
                 <Members>
                     <NoteProperty>
                        <Name>Status</Name>
	                <Value>Success</Value>
                     </NoteProperty>
                 </Members>
             </Type>


      <ParameterizedProperty>: Properties that take arguments and return a 
                               value.

      <Properties>: A collection of the properties of the object.

      <Property>: A property of the base object.

      <PropertySet>: Defines a collection of properties of the object.

         The <PropertySet> tag must have a pair of <Name> tags that specify
         the name of the property set and a pair of <ReferencedProperty> tags
         that specify the properties. The names of the properties are enclosed
         in <Name> tag pairs.       

         In Types.ps1xml, <PropertySet> tags are used to define sets of 
         properties for the default display of an object. You can identify the
         default displays by the value "PsStandardMembers" in the <Name> tag 
         of a <MemberSet> tag.
            
         For example, the following XML creates a Status property for 
         directories (System.IO.DirectoryInfo objects). The value of the Status
         property is always "Success".

             <Type>
                 <Name>System.ServiceProcess.ServiceController</Name>
                 <Members>
                     <MemberSet>
                         <Name>PSStandardMembers</Name>
                         <Members>
                             <PropertySet>
                                 <Name>DefaultDisplayPropertySet</Name>
                                 <ReferencedProperties>
                                     <Name>Status</Name
                                     <Name>Name</Name>
                                     <Name>DisplayName</Name>
                                 </ReferencedProperties>
                             </PropertySet>
                         <Members>
                     <MemberSet>
                 <Members>
             <Type>


     <ScriptMethod>: Defines a method whose value is the output of a script.

         The <ScriptMethod> tag must have a pair of <Name> tags that specify
         the name of the new method and a pair of <Script> tags that enclose
         the script block that returns the method result.       
            
         For example, the ConvertToDateTime and ConvertFromDateTime methods of 
         management objects (System.System.Management.ManagementObject) are
         script methods that use the ToDateTime and ToDmtfDateTime static 
         methods of the System.Management.ManagementDateTimeConverter class. 

             <Type>
                 <Name>System.Management.ManagementObject</Name>
                 <Members>
                     <ScriptMethod>
                         <Name>ConvertToDateTime</Name>
                         <Script>
                             [System.Management.ManagementDateTimeConverter]::ToDateTime($args[0])
                         </Script>
                     </ScriptMethod>
                     <ScriptMethod>
                         <Name>ConvertFromDateTime</Name>
                         <Script>
                             [System.Management.ManagementDateTimeConverter]::ToDmtfDateTime($args[0])
                         </Script>
                     </ScriptMethod>
                 </Members>
             </Type>


      <ScriptProperty>: Defines a property whose value is the output of a 
                        script.

         The <ScriptProperty> tag must have a pair of <Name> tags that specify
         the name of the new property and a pair of <GetScriptBlock> tags
         that enclose the script block that returns the property value.       
            
         For example, the VersionInfo property of files (System.IO.FileInfo
         objects) is a script property that results from using the FullName 
         property of the GetVersionInfo static method of 
         System.Diagnostics.FileVersionInfo objects.

             <Type>
                <Name>System.IO.FileInfo</Name>
                <Members>
                    <ScriptProperty>
                       <Name>VersionInfo</Name>
                       <GetScriptBlock>
                           [System.Diagnostics.FileVersionInfo]::GetVersionInfo($this.FullName)
                       </GetScriptBlock>
                    </ScriptProperty>   
                </Members>
             </Type>


      For more information, see the Windows PowerShell Software Development 
      Kit (SDK) in the MSDN (Microsoft Developer Network )library 
      at http://go.microsoft.com/fwlink/?LinkId=144538.


  Update-TypeData
    
      To load your Types.ps1xml files into a Windows PowerShell console, use
      the Update-TypeData cmdlet. If you want the types in your file to take
      precedence over types in the built-in Types.ps1xml file, use the 
      PrependData parameter of Update-TypeData. Update-TypeData affects only 
      the current console. To make the change to all future consoles, export
      the console, or add the Update-TypeData command to your Windows 
      PowerShell profile.


  Signing a Types.ps1xml File

      To protect users of your Types.ps1xml file, you can sign the file using
      a digital signature. For more information, see about_Signing.
    	

SEE ALSO
    about_Signing
    Copy-Item
    Get-Member
    Update-TypeData

