How can I set ProgId for an electron application?

Question

I have created an electron application. Post Windows 8, setting an application as a default mail client needs the registry value at the following location to be changed:

Computer\HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell\Associations\UrlAssociations\mailto\UserChoice

Since I am using electron-builder to build my application and using nsis target for Windows, where can I create/set/view the ProgId for my application? How can I create more than one ProgIds if it is possible?

Anders Anders · Accepted Answer · 2018-10-29T14:35:20

You cannot override the association like that.

The UserChoice (and FileExts) keys are undocumented and you should not write to them.

Because people force themselves and ignore the issue of "What if two programs did this?" Microsoft has made it increasingly difficult to programmatically set the default association for types/applications.

If you look inside a UserChoice key on recent versions of Windows you will also see a Hash value. If the ProgId value does not match the hash Windows will ignore your attempt to take over the association. Only the ControlPanel/Settings UI can successfully change the association on these systems.

In enterprise environments you can use DISM/GPO. Applications installed by normal users cannot do this, your only option is to follow the Microsoft guidelines:

Register your association the normal documented way in HKEY_CLASSES_ROOT.

Additionally you can:

WinVista & Win7: You can force yourself by using the IApplicationAssociationRegistration interface (Not recommended).
Win8: Ask the user if they want to change their associations and if they confirm you can call IApplicationAssociationRegistrationUI::LaunchAdvancedAssociationUI.
Win10: Call IApplicationAssociationRegistrationUI::LaunchAdvancedAssociationUI to display a help-popup instructing the user how they can change their associations.

LaunchAdvancedAssociationUI can be used in NSIS v3+ like this:

!include LogicLib.nsh
!include Win\COM.nsh
Section
!insertmacro ComHlpr_CreateInProcInstance ${CLSID_ApplicationAssociationRegistrationUI} ${IID_IApplicationAssociationRegistrationUI} r0 ""
${If} $0 P<> 0
    ${IApplicationAssociationRegistrationUI::LaunchAdvancedAssociationUI} $0 '("Internet Explorer")' ; Replace with your registered application name
    ${IUnknown::Release} $0 ""
${EndIf}
SectionEnd

How can I set ProgId for an electron application?

1 Answers