Implementing optional cross-mod features

[Quboid 0]

I have a mod in development that includes a debug panel that shows the item Move It is currently hovering over. It has a button to load that item in the ModTools scene explorer, which works beautifully. But if the user doesn't have ModTools installed, they get this System.Reflection.ReflectionTypeLoadExection exception when the level loads and the mod doesn't run:

Quote

The Mod C:\Users\[Redacted]\AppData\Local\Colossal Order\Cities_Skylines\Addons\Mods\MITE [MITE.dll] has caused an error [ModException]

Details:
System.Reflection.ReflectionTypeLoadException: The classes in the module cannot be loaded.
  at (wrapper managed-to-native) System.Reflection.Assembly:GetTypes (bool)
  at System.Reflection.Assembly.GetTypes () [0x00000] in <filename unknown>:0 
  at Harmony.HarmonyInstance.PatchAll (System.Reflection.Assembly assembly) [0x00000] in <filename unknown>:0 
  at MITE.MITE.OnLevelLoaded (LoadMode loadMode) [0x00000] in <filename unknown>:0 
  at LoadingWrapper.OnLevelLoaded (UpdateMode mode) [0x00000] in <filename unknown>:0 

The mod uses Harmony, but not for the debug panel's ModTools button.

All the code that uses the ModTools reference is in one file, that isn't called by any of the rest of the code (as in, this class is never instantiated). If it uses anything to do with ModTools, the error occurs. So (with this as my entire debug-panel-ModTools-button file; SceneExplorer is a ModTools class), loading the game throws the exception:

using ModTools;

namespace MITE
{
    class ModToolsTest
    {
        public SceneExplorer scene;
    }
}

Whereas this does not throw any exception:

using ModTools;

namespace MITE
{
    class ModToolsTest
    {
        public int scene;
    }
}

Could it be a compiler or project configuration error? I have a reference to 000_ModTools.dll. Or is this a limitation of Harmony?

[boformer 3,169]

I was trying to help you with this, but didn't know you were using Harmony. Harmony causes this issue when you call PatchAll.

Here is what happens when you call it: https://github.com/pardeike/Harmony/blob/master/Harmony/HarmonyInstance.cs#L103-L115

It checks every single type/class of your assembly, also the one that requires ModTools.

Workarounds:

• Use Reflection to call ModTools methods (so that the ModTools assembly is not referenced at all)
• Write a replacement for PatchAll that doesn't load all types in your assembly

Reflection is the safest solution, especially if the integration with ModTools is basic.

[Quboid 0]

Yes, I made a lot of progress thanks to you. I didn't appreciate the importance of Harmony at the time because I was combining source code and getting other errors. I don't have plans beyond basic integration at this time so reflection should work, since the problem isn't just a fixable error in my code.

[AmiPolizeiFunk 446]

I was thinking how useful it would be to have something similar to an eyedropper tool. When I was working with the CSUE/CSUR roads, there were 150+ roads and I didn't have an easy way to figure out which roads were where. I wound up having to do something similar by opening up modtools to see what prefab I was selecting w MoveIt. Would be cool to have an eyedropper mod where you just select anything on the map, and then you can identify it and plop it. Kind of like FindIt!, but a simple point and click version.

[boformer 3,169]

23 minutes ago, AmiPolizeiFunk said:

I was thinking how useful it would be to have something similar to an eyedropper tool. When I was working with the CSUE/CSUR roads, there were 150+ roads and I didn't have an easy way to figure out which roads were where. I wound up having to do something similar by opening up modtools to see what prefab I was selecting w MoveIt. Would be cool to have an eyedropper mod where you just select anything on the map, and then you can identify it and plop it. Kind of like FindIt!, but a simple point and click version.

Sure that's possible.