

ABOUT FORMAT.PS1XML


Short Description

The Format.ps1xml files in Windows PowerShell define the default display of
objects in the Windows PowerShell console. You can create your own
Format.ps1xml files to change the display of objects or to define default
displays for new object types that you create in Windows PowerShell.


Long Description

The Format.ps1xml files in Windows PowerShell define the default display of
objects in Windows PowerShell. You can create your own Format.ps1xml files
to change the display of objects or to define default displays for new
object types that you create in Windows PowerShell.

When Windows PowerShell displays an object, it uses the data in structured
formatting files to determine the default display of the object. The data
in the formatting files determines whether the object is rendered in a
table or in a list, and it determines which properties are displayed by
default.

The formatting affects the display only. It does not affect which object
properties are passed down the pipeline or how they are passed.
Format.ps1xml files cannot be used to customize the output format for
hashtables.

Windows PowerShell includes seven formatting files. These files are located
in the installation directory ($PSHOME). Each file defines the display of a
group of Microsoft .NET Framework objects:

1.  Certificate.Format.ps1xml

    Objects in the Certificate store, such as X.509 certificates and
    certificate stores.

2.  DotNetTypes.Format.ps1xml

    Other .NET Framework types, such as CultureInfo, FileVersionInfo, and
    EventLogEntry objects.

3.  FileSystem.Format.ps1xml

    File system objects, such as files and directories.

4.  Help.Format.ps1xml

    Help views, such as detailed and full views, parameters, and examples.

5.  PowerShellCore.format.ps1xml

    Objects generated by Windows PowerShell core cmdlets, such as
    Get-Member and Get-History.

6.  PowerShellTrace.format.ps1xml

    Trace objects, such as those generated by the Trace-Command cmdlet.

7.  Registry.format.ps1xml

    Registry objects, such as keys and entries.

A formatting file can define four different views of each object: table,
list, wide, and custom. For example, when the output of a Get-ChildItem
command is piped to a Format-List command, Format-List uses the view in the
FileSystem.format.ps1xml file to determine how to display the file and
folder objects as a list.

When a formatting file includes more than one view of an object, Windows
PowerShell applies the first view that it finds.

In a Format.ps1xml file, a view is defined by a set of XML tags that
describe the name of the view, the type of object to which it can be
applied, the column headers, and the properties that are displayed in the
body of the view. The format in Format.ps1xml files is applied just before
the data is presented to the user.


Creating New Format.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 change the display format of an existing object view,
or to add views for new objects, create your own Format.ps1xml files, and
then add them to your Windows PowerShell session.

To create a new file, copy an existing Format.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.

To change the formatting of a current view, locate the view in the
formatting file, and then use the tags to change the view. To create a view
for a new object type, create a new view, or use an existing view as a
model. (The tags are described in the next section of this topic.) You can
then delete all the other views in the file so that the changes are obvious
to anyone examining the file.

When you have saved the changes, use the Update-FormatData cmdlet to add
the new file to your Windows PowerShell session. If you want your view to
take precedence over a view defined in the built-in files, use the
PREPENDPATH parameter of Update-FormatData. Update-FormatData affects only
the current session. To make the change to all future sessions, add the
Update-FormatData command to your Windows PowerShell profile.

Example: Adding Calendar Data to Culture Objects

This example shows how to change the formatting of the culture objects
(System.Globalization.CultureInfo) generated by the Get-Culture cmdlet. The
commands in the example add the calendar property to the default table view
display of culture objects.

The first step is to find the Format.ps1xml file that contains the current
view of the culture objects. The following Select-String command finds the
file:

    Select-String -Path $PSHOME\*format.ps1xml `
      -Pattern System.Globalization.CultureInfo

This command reveals that the definition is in the
DotNetTypes.Format.ps1xml file.

The next command copies the file contents to a new file,
MyDotNetTypes.Format.ps1xml.

    Copy-Item DotNetTypes.Format.ps1xml MyDotNetTypes.Format.ps1xml

Next, open the MyDotNetTypes.Format.ps1xml file in any XML or text editor,
such as Notepad. Find the System.Globalization.CultureInfo object section.
The following XML defines the views of the CultureInfo object. The object
has only a TableControl view.

    <View>
      <Name>System.Globalization.CultureInfo</Name>
      <ViewSelectedBy>
        <TypeName>Deserialized.System.Globalization.CultureInfo</TypeName>
        <TypeName>System.Globalization.CultureInfo</TypeName>
      </ViewSelectedBy>
      <TableControl>
        <TableHeaders>
          <TableColumnHeader>
            <Width>16</Width>
          </TableColumnHeader>
          <TableColumnHeader>
            <Width>16</Width>
          </TableColumnHeader>
          <TableColumnHeader/>
        </TableHeaders>
        <TableRowEntries>
          <TableRowEntry>
            <TableColumnItems>
              <TableColumnItem>
                <PropertyName>LCID</PropertyName>
              </TableColumnItem>
              <TableColumnItem>
                <PropertyName>Name</PropertyName>
              </TableColumnItem>
              <TableColumnItem>
                <PropertyName>DisplayName</PropertyName>
              </TableColumnItem>
            </TableColumnItems>
          </TableRowEntry>
        </TableRowEntries>
      </TableControl>
    </View>

Delete the remainder of the file, except for the opening <?xml>,
<Configuration>, and <ViewDefinitions> tags and the closing
<ViewDefintions> and <Configuration> tags. You must also delete the digital
signature whenever you change the file.

    <?xml version="1.0" encoding="utf-8" ?>
    <Configuration>
    <ViewDefinitions>
    <View>
      <Name>System.Globalization.CultureInfo</Name>
      <ViewSelectedBy>
        <TypeName>Deserialized.System.Globalization.CultureInfo</TypeName>
        <TypeName>System.Globalization.CultureInfo</TypeName>
      </ViewSelectedBy>
      <TableControl>
        <TableHeaders>
          <TableColumnHeader>
            <Width>16</Width>
          </TableColumnHeader>
          <TableColumnHeader>
            <Width>16</Width>
          </TableColumnHeader>
          <TableColumnHeader/>
        </TableHeaders>
        <TableRowEntries>
          <TableRowEntry>
            <TableColumnItems>
              <TableColumnItem>
                <PropertyName>LCID</PropertyName>
              </TableColumnItem>
              <TableColumnItem>
                <PropertyName>Name</PropertyName>
              </TableColumnItem>
              <TableColumnItem>
                <PropertyName>DisplayName</PropertyName>
              </TableColumnItem>
            </TableColumnItems>
          </TableRowEntry>
        </TableRowEntries>
      </TableControl>
    </View>
    </ViewDefinitions>
    </Configuration>

Next, create a new column for the Calendar property by adding a new set of
<TableColumnHeader> tags. The value of the Calendar property can be long,
so a value of 45 characters is used, as follows:

    <TableHeaders>
      <TableColumnHeader>
        <Width>16</Width>
      </TableColumnHeader>
      <TableColumnHeader>
        <Width>16</Width>
      </TableColumnHeader>
      <TableColumnHeader>
        <Width>45</Width>
      </TableColumnHeader>
      <TableColumnHeader/>
    </TableHeaders>

Now, add a new column item in the table rows, as follows:

    <TableRowEntries>
      <TableRowEntry>
        <TableColumnItems>
          <TableColumnItem>
            <PropertyName>LCID</PropertyName>
          </TableColumnItem>
          <TableColumnItem>
            <PropertyName>Name</PropertyName>
          </TableColumnItem>
          <TableColumnItem>
            <PropertyName>Calendar</PropertyName>
          </TableColumnItem>
          <TableColumnItem>
            <PropertyName>DisplayName</PropertyName>
          </TableColumnItem>
        </TableColumnItems>
      </TableRowEntry>
    </TableRowEntries>

After saving the file and closing it, use an Update-FormatData command,
such as the following command, to add the new format file to the current
session. The command uses the PREPENDPATH parameter to place the new file
in a higher precedence order than the original file. For more information
about Update-FormatData, see Update-FormatData.

    Update-FormatData -PrependPath $PSHOME\MyDotNetTypes.format.ps1xml

To test the change, type Get-Culture, and then review the output, which
includes the Calendar property.

    PS C:\> Get-Culture

    LCID Name  Calendar                               DisplayName
    ---- ----  --------                               -----------
    1033 en-US System.Globalization.GregorianCalendar English (United States)


The XML in Format.ps1xml Files

The ViewDefinitions section of each Format.ps1xml file contains the <View>
tags that define each view. A typical <View> tag includes the following
tags:

-   <Name> identifies the name of the view
-   <ViewSelectedBy> specifies the object type or types to which the view
    applies
-   <GroupBy> specifies how items in the view will be combined in groups
-   <TableControl>, <ListControl>, <WideControl>, and <CustomControl>
    contain the tags that specify how each item will be displayed

The <ViewSelectedBy> tag can contain a <TypeName> tag for each object type
to which the view applies. Or, it can contain a <SelectionSetName> tag that
references a selection set that is defined elsewhere by using a
<SelectionSet> tag.

The <GroupBy> tag contains a <PropertyName> tag that specifies the object
property by which items are to be grouped. It also contains either a
<Label> tag that specifies a string to be used as a label for each group or
a <CustomControlName> tag that references a custom control defined
elsewhere using a <Control> tag. The <Control> tag contains a <Name> tag
and a <CustomControl> tag.

The <TableControl> tag typically contains <TableHeaders> and
<TableRowEntries> tags that define the formatting for the table’s heads and
rows. The <TableHeaders> tag typically contains <TableColumnHeader> tags
that contain <Label>, <Width>, and <Alignment> tags. The <TableRowEntries>
tag contains <TableRowEntry> tags for each row in the table. The
<TableRowEntry> tag contains a <TableColumnItems> tag that contains a
<TableColumnItem> tag for each column in the row. Typically, the
<TableColumnItem> tag contains either a <PropertyName> tag that identifies
the object property to be displayed in the defined location, or a
<ScriptBlock> tag that contains script code that calculates a result that
is to be displayed in the location.

Note: Script blocks can also be used elsewhere in locations where
calculated results can be useful.

The <TableColumnItem> tag can also contain a <FormatString> tag that
specifies how the property or the calculated results will be displayed.

The <ListControl> tag typically contains a <ListEntries> tag. The
<ListEntries> tag contains a <ListItems> tag. The <ListItems> tag contains
<ListItem> tags, which contain <PropertyName> tags. The <PropertyName> tags
specify the object property to be displayed at the specified location in
the list. If the view selection is defined using a selection set, the
<ListControl> tag can also contain an <EntrySelectedBy> tag that contains
one or more <TypeName> tags. These <TypeName> tags specify the object type
that the <ListControl> tag is intended to display.

The <WideControl> tag typically contains a <WideEntries> tag. The
<WideEntries> tag contains one or more <WideEntry> tags. A <WideEntry> tag
typically contains a <PropertyName> tag that specifies the property to be
displayed at the specified location in the view. The <PropertyName> tag can
contain a <FormatString> tag that specifies how the property is to be
displayed.

The <CustomControl> tag lets you use a script block to define a format. A
<CustomControl> tag typically contains a <CustomEntries> tag that contains
multiple <CustomEntry> tags. Each <CustomEntry> tag contains a <CustomItem>
tags that can contain a variety of tags that specify contents and
formatting of the specified location in the view, including <Text>,
<Indentation>, <ExpressionBinding>, and <NewLine> tags.


Update-FormatData

To load your Format.ps1xml files into a Windows PowerShell session, use the
Update-FormatData cmdlet. If you want the views in your file to take
precedence over the views in the built-in Format.ps1xml file, use the
PREPENDPATH parameter of Update-FormatData. Update-FormatData affects only
the current session. To make the change to all future sessions, add the
Update-FormatData command to your Windows PowerShell profile.


Default Displays in Types.ps1xml

The default displays of some basic object types are defined in the
Types.ps1xml file in the $PSHOME directory. The nodes are named
PsStandardMembers, and the subnodes use one of the following tags:

-   <DefaultDisplayProperty>
-   <DefaultDisplayPropertySet>
-   <DefaultKeyPropertySet>

For more information, see about_Types.ps1xml.


Tracing Format.ps1xml File Use

To detect errors in the loading or application of Format.ps1xml files, use
the Trace-Command cmdlet with any of the following format components as the
value of the NAME parameter:

-   FormatFileLoading
-   FormatViewBinding
-   UpdateFormatData

For more information, see Trace-Command and Get-TraceSource.


Signing a Format.ps1xml File

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


See Also

Update-FormatData

Trace-Command

Get-TraceSource
