Safe removal of a mod

[Ippo]

Hello everyone,

my testers users notified me of a problematic bug.

My mod uses PartModules extensively, and obviously they are saved in the ship's persistent file. If one has a ship in flight and removes my mod, then a long stream of NREs is thrown when the ship is selected in the tracking station, and cannot be flown.

I get that basically the game is trying to load the module from the save file, but the module doesn't exist anymore, therefore the failures.

My question is: is there a way to design a mod that can be safely removed from crafts that are in-flight?

[Diazo]

How exactly are you adding the partmodules and to what?

For my mod, I add the partmodule via modulemanager and a part.cfg. Removing my mod causes no errors to be thrown by KSP.

Now, I do have a pretty basic implementation of a partmodule that I'm just storing some strings in, but at a basic level it looks like partmodules should be okay to just leave behind when a mod is uninstalled..

D.

Edited June 29, 2014 by Diazo

[Ippo]

I am doing the same: I have some partmodules that are added via the module manager cfg files.

I add my modules to a lot of parts, and they all have a quite big state stored in them, but conceptually it seems to be just like your case.

[Diazo]

My only thought then is are you nesting partmodules somehow? Or it is the fancier data types maybe?

When I say I'm only storing strings, that is all I'm storing. Well, 5 strings and 1 bool, but I'd consider a bool an even simpler data type then a string.

Or have you got a custom data type that KSP can't recognize because the definition for it is in your mod?

I'm really just throwing things at the wall and seeing what sticks here. Is this for one of your mods that you have the source posted somewhere so I could take a look?

D.

[Mihara]

Generally, a module that is missing will not produce a NRE, the part loader will complain that the part cannot load a module, and it will be saved to the persistence without any records pertaining to this module when the next time to save persistence comes up. I.e. normally, a PartModule-installing plugin is perfectly safe to remove, though I suppose some things, like TweakScale, may be the exception, depending on whether they modify the part after it starts or not.

If you're getting NRE, there's got to be something more interesting going on in there.

[Ippo]

My only thought then is are you nesting partmodules somehow? Or it is the fancier data types maybe?

Actually no, it's just a plain part module. Also, I'm storing only floats, bools and in one case a string.

All my modules (except for one) are derived from this class.

There is also another class that acts as a runtime configuration manager.

If you're getting NRE, there's got to be something more interesting going on in there.

Well, the silver lining is that I'm not doing something glaringly wrong

[Mihara]

All my modules (except for one) are derived from this class.

Hmmmm... You know what, this might be it.

I'm not sure if everything that handles PartModules actually correctly handles classes that inherit classes that inherit PartModules. I know it's a problem with science modules, at least.

[Ippo]

hmmmm... You know what, this might be it.

I'm not sure if everything that handles partmodules actually correctly handles classes that inherit classes that inherit partmodules. I know it's a problem with science modules, at least.

awesome.