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.
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