Afrow UK
21st November 2005 14:35 UTC

Feature request perhaps
I have a feature request but I thought I'd ask you all about it first in case there is another way about it.

In the past few months I've written a number of plugins that modify existing NSIS pages (ScrollLicense, ToggleInstFiles etc) rather than create their own pages.

I've created a built-in Unload function which is called without /NOUNLOAD which puts the window procedures back to the originals and lets NSIS delete the plugin DLL (and $PLUGINSDIR folder).

The problem that I have is that there's no good way to unload the plugins. If you call the plugin Unload function from the Leave function, it crashes the installer which also occurs when calling it in the abort function (when user clicks Cancel). I'm guessing this is because the dialog is no longer in memory then?

So basically the problem is that I need to call this Unload function when the user leaves my modified page (Next, Back, Cancel) and before they close the installer. The best way that worked 100% for this was when using a Custom page and placing the Unload function directly under the InstallOptions::dialog call.

Now, my feature request would be for normal pages: Could a new optional parameter be added to the Page / PageCallbacks instructions to set a function which is called when the user clicks ANY of the Next, Back or Cancel buttons while the Page is still in view. Here I can safely call the Unload function.

Cheers!

-Stu

deguix
21st November 2005 20:23 UTC

Maybe there is a place where the "/NOUNLOAD" was not used before this call or, like you said, plug-in problem which doesn't return something to NSIS control or something not freed after the plug-in is freed from memory. Maybe some code would clarify this more.

btw, there is a very old InstallOptions modification which supports to unload the plug-in using a function. If I remember right, it is a little buggy in this too.

EDIT:

Now, my feature request would be for normal pages: Could a new optional parameter be added to the Page / PageCallbacks instructions to set a function which is called when the user clicks ANY of the Next, Back or Cancel buttons while the Page is still in view. Here I can safely call the Unload function.

Afrow UK
21st November 2005 22:06 UTC

Ok thanks I'll have a look at WM_NOTIFY_OUTER_NEXT.

There is still the problem that the plugin needs to be called atleast once without /NOUNLOAD before closing the installer. Otherwise the plugin won't get deleted. It seems that NSIS doesn't unload a plugin when closing the installer and it only becomes deletable after you close the installer.

-Stu

Animaether
21st November 2005 23:48 UTC

It's odd - the ScrollLicense example file, for example, works perfectly - but within my larger file (sorry, can't post/provide - if I get time to narrow it down, I will) I do get a crash when the installer closes. Nasty one, too, DrWatson gets all confused by it :)

I've since resorted to storing the plugin dir in a temporary registry location and launching a second, silent installer that pauses for a few seconds at the end of the first installer. This second installer grabs the plugin directory from the registry, zaps its contents, then the dir itself (if empty), then removes the registry entry.

Afrow UK
22nd November 2005 08:37 UTC

Yeh that's what I resorted to also when writing a plugin for a fellow NSIS member. The exe is ran in .onGUIEnd and deletes all ns*.tmp folders in $TEMP.

I'll have a look if I can fix the problem with ScrollLicense (and the others) because crashes are nasty :/

-Stu

kichik
22nd November 2005 19:04 UTC

Originally posted by Afrow UK
There is still the problem that the plugin needs to be called atleast once without /NOUNLOAD before closing the installer. Otherwise the plugin won't get deleted. It seems that NSIS doesn't unload a plugin when closing the installer and it only becomes deletable after you close the installer.

Afrow UK
22nd November 2005 20:28 UTC

Thanks kichik.
Here's the code that I've made but it doesn't seem to work.

HANDLE hNewThread;
HMODULE phModule = GetModuleHandle("ExitButton2.dll");

SetWindowLongPtr(hWndDlg, GWL_WNDPROC,  (LONG)ParentWndProcOld);
SetWindowLongPtr(hWndDlg, DWLP_DLGPROC, (LONG)ParentDlgProcOld);
SendMessage(hWndDlg, g_uMsgCreate, FALSE, (LPARAM)hWndDlg);

CreateThread(NULL, 0, UnloadPluginThread, phModule, 0, NULL);

...

DWORD WINAPI UnloadPluginThread(LPVOID lpParam)
{
  HMODULE hDll = (HMODULE)lpParam;
  FreeLibraryAndExitThread(hDll, 0);
}

Animaether
22nd November 2005 20:46 UTC

Could you post again when/if you've updated the plugins?
I'd love to give it a try again and see if things don't crash with the new methods - the post-install deleter thing scares me a bit :)

Afrow UK
24th November 2005 21:23 UTC

*bump* :)

-Stu

Animaether
24th November 2005 21:54 UTC

bump ? Not seeing the update - am I being too eager? ;)

oh, I'm blind. nevermind me.

I second the bump - Kichik ? :)

kichik
25th November 2005 16:09 UTC

Why not call the Unload function in .onGUIEnd like with BgImage? That callback function is executed after the dialog is ended. That means no further window messages will be processed.

Afrow UK
27th November 2005 18:26 UTC

That works lol
I didn't like the fact that my window procedures would still be in use until you close the installer, but I guess that'll just have to be... shouldn't cause any problems hopefully.

Uploaded ScrollLicense and ToggleInstFiles which both use .onGUIEnd to Unload in the examples.

-Stu

Animaether
28th November 2005 03:11 UTC

that works :D Thanks to both of you :)