Thursday, June 5, 2008

Scripting - Create a desktop shortcut to a URL (Updated for IE7)

This article discusses a script that creates a desktop shortcut to a particular URL, with a given custom icon. I know, pretty routine stuff, but when the requirement of a project is to deploy a 'desktop shortcut' to affected customers, I often find that deploying such a script on a web site, such that it can be accessed on demand, or pushing out via a login script or other type of automated technology meets the requirement.

The script:


  1. Copies a custom icon from a network share to the local computer (so the icon shows up, even if the user is offline)

  2. Creates a shortcut on the desktop, references the custom icon

  3. Prompts the user if they wish to launch the site immediately



I developed this script a number of years ago, and recently had the opportunity to re-use it for another app. Unfortunately, upon initial run, it worked except for the custom icon, it was using the default browser icon instead. Thought maybe I broke something because I had also modified the target location of the custom icon to support Vista (as well as 9x-XP). I then tested versions of it I had written in the past that were still in production, those had the same issue.

Turns out the issue was on computers with Internet Explorer 7. Internet Explorer 6 computers were fine. The IE7 computer had a slightly different format in the *.url files placed on the desktop. Didn't discover this until I opened up the .url file in notepad to compare one the script created, to one that was manually created.

In IE6, the url's were basically this format:



[InternetShortcut]
URL=http://intranet/MyApp
IconIndex=0
IconFile=C:\Documents and Settings\TestUser\Application Data\MyApp.ico

While it is in ini file format (note the section 'InternetShortcut' in square brackets), there was only one section, so we were able to get away with simply appending the property=value lines to the file, as in the following snippent



Dim fso
Set fso = WScript.createobject("Scripting.FileSystemObject")

Dim f
Set f = fso.getfile(sURLLinkFile)

Dim contents
contents = ""

Dim line

Dim ots
Set ots = f.openastextstream(1)

'read in contents of the file, except for any existin icon settings
do while not ots.atEndofstream
line = ots.readline
if instr(1,line,"IconIndex",1) = 0 and instr(1,line,"IconFile",1) = 0 then
contents = contents & line & vbcrlf
end if
loop
ots.close

'add the lines for iconindex and file
if not (isnull(iIconIndex) or isnull(IconLocation)) then
if not (isempty(iIconIndex) or isempty(IconLocation)) then
contents=contents &"IconIndex=" & cstr(iIconIndex) & vbcrlf
contents=contents & "IconFile=" & IconLocation
end if
end if

set ots = f.openastextstream(2)
ots.write contents
ots.close

set ots = nothing
set f = nothing
set fso = nothing

The IE7 version has added a section (notice the GUID in square brackets on the 4th line) and a few more properties


So, absent any change in the script, the .URL files were coming out as:



[InternetShortcut]
URL=http://intranet/MyApp
IDList=
HotKey=0
[{000214A0-0000-0000-C000-000000000046}]
Prop3=19,2
IconIndex=0
IconFile=C:\Documents and Settings\TestUser\Application Data\MyApp.ico

With the Icon reference essentially in the 'wrong' section, no .url appears with the standard browser icon. This appeared to be true regardless of default browser (i.e. FireFox, etc.) just having IE7 vs. IE6. (Computers that had created shortcuts while on IE6, then upgrading to IE7, appeared OK.)


To resolve, grabbed some INI read-write functions from http://www.motobit.com, which, after including the functions, cleaned up the core code quite a bit anyway:



WriteINIString "InternetShortcut", "IconIndex", iIconIndex, sURLLinkFile
WriteINIString "InternetShortcut", "IconFile", IconLocation, sURLLinkFile

So we end up with:



[InternetShortcut]
URL=http://intranet/MyApp
IDList=
HotKey=0
IconIndex=0
IconFile=C:\Documents and Settings\TestUser\Application Data\MyApp.ico
[{000214A0-0000-0000-C000-000000000046}]
Prop3=19,2

Excellent stuff, right? So here's the full code:



'-------------------------------------------------------------------------------
'Creates a desktop 'shortcut', or 'icon' to a given URL
'Runs with limited-rights user, so you can give users the ability to create a
'shortcut on-demand, or roll out with a login script or similar automated device
' Author Chris Anderson cander@realworldis.com
' - Modified the script to drop the custom icon, if specified into the current users 'app data' folder
' more logo-compliant than the old version which hard-coded c:\program files\. it will now run under a
' limited rights user
' - Added prompt to launch the site after creating the shortcut
' - Modified the shortcut creation to be compatible with IE7, the previous version would create the shortcut
' successfully, but the custom icon would not be used.
'-------------------------------------------------------------------------------
Option Explicit

Const URL_SHORTCUT_NAME = "My Intranet Application"
Const TARGET_PATH = "http://intranet/MyApp"
Const ICON_REMOTE_FILE_PATH = "\\server\public\MyApp\MyApp.ico"

'the icon index can allow you to reference an ico resource in the file with many resources (i.e. and .exe or .dll)
'if using a seperate .ico file, set to 0
Dim iIconIndex
iIconIndex = 0

Dim sLocalIconFilePath

'copy icon locally so it shows up regardless of network connection
'logo-compliancy - copy the file to the current users 'Application Data' as they should have write access even when not-admin
CopyIconToLocalApplicationData ICON_REMOTE_FILE_PATH, sLocalIconFilePath

'the script then creates a shortcut on their desktop, to the target url, with the local path of the icon
CreateURLShortcut URL_SHORTCUT_NAME, TARGET_PATH, sLocalIconFilePath

'prompt the user to open the shortcut now
Dim sMessage
sMessage = "There is now an icon on your desktop for " & URL_SHORTCUT_NAME & ". Would you like to open it now?"

if MsgBox(sMessage,vbYesNo) = vbYes then
OpenPath TARGET_PATH
end if

Private Sub CreateURLShortcut(ByVal ShortcutName, Byval TargetPath, ByVal IconLocation)

Dim WSHShell
Set WSHShell = createobject("wscript.shell")

Dim sDesktop
sDesktop= WSHShell.specialfolders("Desktop")

Dim oURLLink
Set oURLLink = WSHShell.createshortcut(sDesktop & "\" & ShortcutName & ".url")
oURLLink.targetpath = TargetPath
oURLLink.save

Dim sURLLinkFile
sURLLinkFile = oURLLink.FullName

'set the icon file
if Not IsEmpty(iIconIndex) AND NOT IsEmpty(IconLocation) Then

'WScript.Echo IconLocation

WriteINIString "InternetShortcut", "IconIndex", iIconIndex, sURLLinkFile
WriteINIString "InternetShortcut", "IconFile", IconLocation, sURLLinkFile

end if

set oURLLink = nothing
set WSHShell = nothing

End Sub

Private Sub CopyIconToLocalApplicationData(Byval RemotePath, ByRef LocalPath)

Dim WSHShell
Set WSHShell = WScript.CreateObject("WScript.Shell")

Dim fso
Set fso = CreateObject("Scripting.filesystemobject")

Dim objFile
Set objFile = fso.GetFile(RemotePath)

'local path will be directly under the users app data
LocalPath = WSHShell.ExpandEnvironmentStrings("%AppData%") & "\" & fso.GetFileName(objFile)

fso.CopyFile RemotePath, LocalPath

Set fso = Nothing

Set WSHShell = Nothing

End Sub

private sub OpenPath(byval TargetPath)

Dim WSHShell
Set WSHShell = createobject("shell.application")

WSHShell.Open TargetPath

set WSHShell = nothing

end sub


'----------------------------------------------------------------
'INI File Handling

'Work with INI files In VBS (ASP/WSH)
'v1.00
'2003 Antonin Foller, PSTRUH Software, http://www.motobit.com
'Function GetINIString(Section, KeyName, Default, FileName)
'Sub WriteINIString(Section, KeyName, Value, FileName)
'----------------------------------------------------------------

Sub WriteINIString(Section, KeyName, Value, FileName)
Dim INIContents, PosSection, PosEndSection

'Get contents of the INI file As a string
INIContents = GetFile(FileName)

'Find section
PosSection = InStr(1, INIContents, "[" & Section & "]", vbTextCompare)
If PosSection>0 Then
'Section exists. Find end of section
PosEndSection = InStr(PosSection, INIContents, vbCrLf & "[")
'?Is this last section?
If PosEndSection = 0 Then PosEndSection = Len(INIContents)+1

'Separate section contents
Dim OldsContents, NewsContents, Line
Dim sKeyName, Found
OldsContents = Mid(INIContents, PosSection, PosEndSection - PosSection)
OldsContents = split(OldsContents, vbCrLf)

'Temp variable To find a Key
sKeyName = LCase(KeyName & "=")

'Enumerate section lines
For Each Line In OldsContents
If LCase(Left(Line, Len(sKeyName))) = sKeyName Then
Line = KeyName & "=" & Value
Found = True
End If
NewsContents = NewsContents & Line & vbCrLf
Next

If isempty(Found) Then
'key Not found - add it at the end of section
NewsContents = NewsContents & KeyName & "=" & Value
Else
'remove last vbCrLf - the vbCrLf is at PosEndSection
NewsContents = Left(NewsContents, Len(NewsContents) - 2)
End If

'Combine pre-section, new section And post-section data.
INIContents = Left(INIContents, PosSection-1) & _
NewsContents & Mid(INIContents, PosEndSection)
else'if PosSection>0 Then
'Section Not found. Add section data at the end of file contents.
If Right(INIContents, 2) <> vbCrLf And Len(INIContents)>0 Then
INIContents = INIContents & vbCrLf
End If
INIContents = INIContents & "[" & Section & "]" & vbCrLf & _
KeyName & "=" & Value
end if'if PosSection>0 Then
WriteFile FileName, INIContents
End Sub

Function GetINIString(Section, KeyName, Default, FileName)
Dim INIContents, PosSection, PosEndSection, sContents, Value, Found

'Get contents of the INI file As a string
INIContents = GetFile(FileName)

'Find section
PosSection = InStr(1, INIContents, "[" & Section & "]", vbTextCompare)
If PosSection>0 Then
'Section exists. Find end of section
PosEndSection = InStr(PosSection, INIContents, vbCrLf & "[")
'?Is this last section?
If PosEndSection = 0 Then PosEndSection = Len(INIContents)+1

'Separate section contents
sContents = Mid(INIContents, PosSection, PosEndSection - PosSection)

If InStr(1, sContents, vbCrLf & KeyName & "=", vbTextCompare)>0 Then
Found = True
'Separate value of a key.
Value = SeparateField(sContents, vbCrLf & KeyName & "=", vbCrLf)
End If
End If
If isempty(Found) Then Value = Default
GetINIString = Value
End Function

'Separates one field between sStart And sEnd
Function SeparateField(ByVal sFrom, ByVal sStart, ByVal sEnd)
Dim PosB: PosB = InStr(1, sFrom, sStart, 1)
If PosB > 0 Then
PosB = PosB + Len(sStart)
Dim PosE: PosE = InStr(PosB, sFrom, sEnd, 1)
If PosE = 0 Then PosE = InStr(PosB, sFrom, vbCrLf, 1)
If PosE = 0 Then PosE = Len(sFrom) + 1
SeparateField = Mid(sFrom, PosB, PosE - PosB)
End If
End Function


'File functions
Function GetFile(ByVal FileName)
Dim FS: Set FS = CreateObject("Scripting.FileSystemObject")
'Go To windows folder If full path Not specified.
If InStr(FileName, ":\") = 0 And Left (FileName,2)<>"\\" Then
FileName = FS.GetSpecialFolder(0) & "\" & FileName
End If
On Error Resume Next

GetFile = FS.OpenTextFile(FileName).ReadAll
End Function

Function WriteFile(ByVal FileName, ByVal Contents)

Dim FS: Set FS = CreateObject("Scripting.FileSystemObject")
'On Error Resume Next

'Go To windows folder If full path Not specified.
If InStr(FileName, ":\") = 0 And Left (FileName,2)<>"\\" Then
FileName = FS.GetSpecialFolder(0) & "\" & FileName
End If

Dim OutStream: Set OutStream = FS.OpenTextFile(FileName, 2, True)
OutStream.Write Contents
End Function

2 comments:

Shawn said...

Chris,

I read your article about creating a desktop shortcut to a url and it has been very helpful. I am however running into a problem. Here’s my situation.

I have a website coded in asp. I have placed a button on the website that will allow the user to click and create a “One-click login” to our site. Basically it’s just a shortcut that has the url with username/password as parameters. Following your example I am able to create the shortcut on the desktop, but the shortcut is created on the desktop of the web server and not the desktop of the user connecting to the website.

Can this be done? Thank you for your time.

Chris Anderson said...

The problem discussed above is basically related to breaking out of the 'sandbox' that is the browser. Web pages/apps(server-side technologies such as ASP, ASP.net, PHP, etc. and client-side such as Javascript) generally can only interact within their own 'window'. For your web app to interact outside of that, would require either the user's security be set very low, or sometimes a trusted environment like a company intranet. Although this is germane to all server-side technologies, this is a common question of VBScript/ASP since the server-side ASP syntax is essentially the same as when using it under the Scripting Host on the desktop, but they are two different environments.

Two possible paths:
1. Simply link to the .vbs file on the server.
2. Create a HyperText application (HTA) with a user interface that will create the script. The ScriptCenter has a good article series, Wrap Your Scripts Up in a GUI Interface
Inside of an HTA, you can essentially write script that will operate as if you were sitting at the user's desktop.

Drawback of both of these is that the user needs to give explicit permission to message boxes that might not be the most user-friendly. Depending on browser settings and security software, the user may see one of the following in response to clicking your script:
1. Nothing at all
2. Prompt to save your VBS or HTA
2. Actually be able to run it after 1-2 clicks

I would recommend this only in a trusted environment like a company intranet. For an open web site, the confusion factor seems to outweigh the convenience for some.