Module setup with UDeveloperSetting validation

MyConfigModule.cpp

#include "MyConfigModule.h"

#include <Core/Public/Misc/MessageDialog.h>
#include <CoreUObject/Public/Misc/DataValidation.h>
#include <CoreUObject/Public/Misc/UObjectToken.h>
#include <UnrealEd/Public/Editor.h>

#include "MyConfig/ProjectSetting/MyConfig.h"

namespace
{
const auto RunConfigValidation = []() -> FMessageLog
{
	FMessageLog ConfigLoadLog("LoadErrors");

	// Need a mutable version of the config to call IsDataValid
	const auto Config = GetMutableDefault<UMyConfig>();
	if (!IsValid(Config))
	{
		return ConfigLoadLog;
	}

	FDataValidationContext ValidationContext;
	const auto ValidationResult = Config->IsDataValid(ValidationContext);

	if (ValidationResult == EDataValidationResult::Valid)
	{
		return ConfigLoadLog;
	}

	ConfigLoadLog
		.Error() //
		->AddToken(FUObjectToken::Create(Config))
		->AddToken(FTextToken::Create(INVTEXT("has validation issues! See messages below:")));

	for (auto& Issue : ValidationContext.GetIssues())
	{
		ConfigLoadLog
			.Message(Issue.Severity) //
			->AddToken(FUObjectToken::Create(Config))
			->AddToken(FTextToken::Create(Issue.Message));
	}

	return ConfigLoadLog;
};
} // namespace

void FMyConfig::StartupModule()
{
	FCoreDelegates::OnPostEngineInit.AddLambda(
		[]
		{
			auto ResultLog = RunConfigValidation();
			if (ResultLog.NumMessages(EMessageSeverity::Warning) > 0)
			{
				FMessageDialog::Open(EAppMsgType::Ok, INVTEXT("UI Config is invalid! UI will be unpredictable. Check the file Config/DefaultUIConfig.ini"));
			}
		});
	FCoreDelegates::OnEnginePreExit.AddLambda(
		[]
		{
			auto ResultLog = RunConfigValidation();
			if (ResultLog.NumMessages(EMessageSeverity::Warning) > 0)
			{
				FMessageDialog::Open(EAppMsgType::Ok, INVTEXT("UI Config is invalid! Check the file Config/DefaultUIConfig.ini"));
			}
		});

#if WITH_EDITOR
	FEditorDelegates::BeginPIE.AddLambda(
		[](bool bIsSimulating)
		{
			auto ResultLog = RunConfigValidation();
			if (ResultLog.NumMessages(EMessageSeverity::Warning) > 0)
			{
				ResultLog.Notify(INVTEXT("UI Config has validations issues that needs to be fixed! UI will be unpredictable."), EMessageSeverity::Warning);

				FMessageDialog::Open(EAppMsgType::Ok, INVTEXT("UI Config is invalid! See the LoadErrors message log."));
			}
		});
#endif
}

void FMyConfig::ShutdownModule()
{
#if WITH_EDITOR
	FEditorDelegates::BeginPIE.RemoveAll(this);
#endif
	FCoreDelegates::OnEnginePreExit.RemoveAll(this);
	FCoreDelegates::OnPostEngineInit.RemoveAll(this);
}

IMPLEMENT_MODULE(FMyConfig, MyConfig)

MyConfigModule.h

#pragma once

#include <CoreMinimal.h>
#include <Modules/ModuleManager.h>

class FMyConfig : public IModuleInterface
{
public:
	// Begin IModuleInterface
	void StartupModule() override;
	void ShutdownModule() override;
	// End IModuleInterface
};