Using Help in PowerShell ISE

Windows PowerShell Integrated Scripting Environment (ISE) comes with a graphical help file (chm) which contains complete help for PowerShell as well as help for using ISE. The help file is located under C:\Windows\Help\Mui\<LCID>.

To invoke help, press F1:

ISE’s help is also context-sensitive in terms of cmdlet names. If you press F1 while your mouse cursor is positioned inside a cmdlet name, help is displayed for the corresponding cmdlet:

Note: Context sensitive help doesn’t work for aliases, more on this below.

You can also disable local help and force ISE to get help directly from Technet:

$psISE.Options.LocalHelp = $false

Now, verify that the cursor is positioned accordingly and press F1, help is coming in from the internet:

ISE support two types of help: Local and Online, both implemented in two variables: $psLocalHelp and $psOnlineHelp

PS > $psLocalHelp

Key                 Value                                                                    
---                 -----                                                                    
Add-Computer        WindowsPowerShellHelp.chm::/html/093f660c-b8d5-43cf-aa0c-54e5e54e76f9.htm
Add-Content         WindowsPowerShellHelp.chm::/html/0c836a1b-f389-4e9a-9325-0f415686d194.htm
Add-History         WindowsPowerShellHelp.chm::/html/9c7c19cd-56e8-4fb2-b476-3adc589f7a97.htm
Add-Member          WindowsPowerShellHelp.chm::/html/568588f6-4fed-47e5-819f-2cd326b71ed4.htm
Add-PsSnapin        WindowsPowerShellHelp.chm::/html/153a2236-80bd-4f12-9852-411471f92441.htm
(...)
 
 
PS > $psOnlineHelp

Key                 Value                                        
---                 -----                                        
Add-Computer        http://go.microsoft.com/fwlink/?LinkID=135194
Add-Content         http://go.microsoft.com/fwlink/?LinkID=113278
Add-History         http://go.microsoft.com/fwlink/?LinkID=113279
Add-Member          http://go.microsoft.com/fwlink/?LinkID=113280
Add-PsSnapin        http://go.microsoft.com/fwlink/?LinkID=113281
(...)

Both variables are generic types (System.Management.Automation.Host.ObservableDictionary`2), similar to Hash Tables they have Key/Value pair members, each of which contains a cmdlet name and a pointer to the help page location.

I wanted to mimic the way ISE’s help works when you press F1 and allow an alias to be expanded to cmdlet name. With these functions the cursor position doesn’t have to be inside the name, it can be on either side as well as inside a name/alias, allowing you to get help for one letter long aliases. To use the functions, execute the code in ISE or include them in your ISE profile (you can also download them from the ‘Attachment’ section at the end of this post).

function Get-LocalHelp{
    
   # check if local help is disabled
   if(!$psIse.Options.LocalHelp)
    {
       throw 'Local help is disabled. To enable Local help execute:'+"`n"+ 
           'PS > $psISE.Options.LocalHelp=$true'
    }
    
   # get the caret position and current line
   $col = $psIse.CurrentOpenedFile.Editor.CaretColumn 
   $line = $psIse.CurrentOpenedFile.Editor.CaretLine
    
   # tokenize the active editor script
   $content = $psIse.CurrentOpenedFile.Editor.Text
   $tokens = [System.Management.Automation.PsParser]::Tokenize($content,[ref]$null)
    
   #                                       
   $cmd = $tokens |where {$_.StartLine -eq $line `
                           -AND $_.StartColumn -le $col -AND $_.EndColumn -ge $col }
       
   if($cmd)
    {    
       if($psLocalHelp.ContainsKey($cmd.content))
        {
            hh.exe$psLocalHelpitem($cmd.content)
           return
        }


       $alias =  (Get-Alias |where {$_.Name -eq $cmd.content}).Definition
       if ($alias)
        {
            hh.exe $psLocalHelp.item($alias)    
        }
    }                

}

function Get-OnlineHelp{
   # online help is displayed in default browser

   $col = $psIse.CurrentOpenedFile.Editor.CaretColumn 
   $line = $psIse.CurrentOpenedFile.Editor.CaretLine
    
   $content = $psIse.CurrentOpenedFile.Editor.Text
   $tokens = [System.Management.Automation.PsParser]::Tokenize($content,[ref]$null)
    
   $cmd = $tokens | where {$_.StartLine -eq $line `
                           -AND $_.StartColumn -le $col -AND $_.EndColumn -ge $col }
    

   if($cmd)
    {
       if($psOnlineHelp.ContainsKey($cmd.content))
        {
            [Diagnostics.Process]::Start($psOnlineHelp.item($cmd.content))
           return
        }


       $alias = (Get-Alias | where {$_.Name -eq $cmd.content}).Definition
       if ($alias)
        {   
            [Diagnostics.Process]::Start($psOnlineHelp.item($alias))
        }
    }

}


# register shortcut keys
$null = $psIse.customMenu.subMenus.add("Get-PSLocalHelp",{Get-LocalHelp},"CTRL+F1")
$null = $psIse.customMenu.subMenus.add("Get-PSOnlineHelp",{Get-OnlineHelp},"CTRL+F2")