about_Data_Sections

TOPIC
	about_Data_Sections

SHORT DESCRIPTION
	Explains Data sections, which isolate text strings and other read-only
	data from script logic.


LONG DESCRIPTION
	Scripts that are designed for Windows PowerShell can have one or more
	Data sections that contain only data. You can include one or more Data 
	sections in any script, function, or advanced function. The content of
	the Data section is restricted to a specified subset of the Windows
	PowerShell scripting language.

	Separating data from code logic makes it easier to identify and manage 
	both logic and data. It lets you have separate string resource files for 
	text, such as error messages and Help strings. It also isolates the code 
	logic, which facilitates security and validation tests. 

	In Windows PowerShell, the Data section is used to support script
	internationalization. You can use Data sections to make it easier to
	isolate, locate, and process strings that will be translated into many
	user interface (UI) languages. 

	The Data section is a Windows PowerShell 2.0 feature. Scripts with Data
	sections will not run in Windows PowerShell 1.0 without revision.


  Syntax

	The syntax for a Data section is as follows:

		DATA [-supportedCommand <cmdlet-name>] {

			<Permitted content>
	}


	The Data keyword is required. It is not case-sensitive.


	The permitted content is limited to the following elements:

		- All Windows PowerShell operators, except -match	 
		 
		- If, Else, and ElseIf statements
		 
		- The following automatic variables: $PsCulture,  $PsUICulture,  $True,
		$False, and $Null

		- Comments

		- Pipelines

		- Statements separated by semicolons (;)

		- Literals, such as the following:

			a

			1
  
			1,2,3
	
			"Windows PowerShell 2.0"

			@( "red", "green", "blue" )

			@{ a = 0x1; b = "great"; c ="script" }

			[XML] @'
			 <p> Hello, World </p>
			'@

		- Cmdlets that are permitted in a Data section. By default, only the 
		ConvertFrom-StringData cmdlet is permitted.

		- Cmdlets that you permit in a Data section by using the 
		SupportedCommand parameter.


	When you use the ConvertFrom-StringData cmdlet in a Data section, you can
	enclose the key/value pairs in single-quoted or double-quoted strings or in 
	single-quoted or double-quoted here-strings. However, strings that contain
	variables and subexpressions must be enclosed in single-quoted strings or
	in single-quoted here-strings so that the variables are not expanded and the
	subexpressions are not executable. 


  SupportedCommand

	The SupportedCommand parameter allows you to indicate that a cmdlet or 
	function generates only data. It is designed to allow users to include 
	cmdlets and functions in a data section that they have written or tested.

	The value of SupportedCommand is a comma-separated list of one or more 
	cmdlet or function names.

	For example, the following data section includes a user-written cmdlet, 
	Format-XML, that formats data in an XML file:

		DATA -supportedCommand Format-XML 
		{ 
			 Format-XML -strings string1, string2, string3
	}
	 


  Using a Data Section

	To use the content of a Data section, assign it to a variable and use
	variable notation to access the content.

	For example, the following data section contains a ConvertFrom-StringData
	command that converts the here-string into a hash table. The hash table
	is assigned to the $TextMsgs variable. 

	The $TextMsgs variable is not part of the data section.
 
		$TextMsgs = DATA {
			ConvertFrom-StringData -stringdata @'
				Text001 = Windows 7
				Text002 = Windows Server 2008 R2
		'@
	}
	 
	To access the keys and values in hash table in $TextMsgs, use the
	following commands.

		$TextMsgs.Text001
		$TextMsgs.Text002



EXAMPLES

	Simple data strings.

		DATA {
			"Thank you for using my Windows PowerShell Organize.pst script."
			"It is provided free of charge to the community."
			"I appreciate your comments and feedback."
	}


	Strings that include permitted variables.

		DATA {
			if ($null) {
			 "To get help for this cmdlet, type get-help new-dictionary."
		}
	}	 
			

	A single-quoted here-string that uses the ConvertFrom-StringData cmdlet:

		DATA {
		ConvertFrom-StringData -stringdata @'
			Text001 = Windows 7
			Text002 = Windows Server 2008 R2
		'@
	}



	A double-quoted here-string that uses the ConvertFrom-StringData cmdlet:

		DATA  {
		ConvertFrom-StringData -stringdata @"
			Msg1 = To start, press any key.
			Msg2 = To exit, type "quit".
		"@
	}



	A data section that includes a user-written cmdlet that generates data:

		DATA -supportedCommand Format-XML { 
		 Format-XML -strings string1, string2, string3
	}


SEE ALSO
	about_Automatic_Variables
	about_Comparison_Operators
	about_Hash_Tables
	about_If
	about_Operators
	about_Quoting_Rules
	about_Script_Internationalization
	ConvertFrom-StringData
	Import-LocalizedData