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Migration Guide

This page documents breaking changes and migration steps between versions of FWGASSystem.

Version 1.0 (Current)

This is the initial release. No migration steps are required.

Engine Version Compatibility

FWGASSystem includes engine version checks for API differences between UE versions:

#if ENGINE_MAJOR_VERSION == 5 && ENGINE_MINOR_VERSION >= 3
    virtual EDataValidationResult IsDataValid(class FDataValidationContext& Context) const override;
#else
    virtual EDataValidationResult IsDataValid(FDataValidationContext& Context) override;
#endif

When upgrading your project's engine version, the plugin handles these differences automatically. No manual changes are required.

Migrating from Raw GAS to FWGASSystem

If you have an existing project using raw Gameplay Ability System and want to adopt FWGASSystem, follow these steps:

Step 1: Replace the AbilitySystemComponent

AbilitySystem = CreateDefaultSubobject<UAbilitySystemComponent>(TEXT("ASC"));

AbilitySystem = CreateDefaultSubobject<UFWAbilitySystemComponent>(TEXT("ASC"));

Move your manual ability granting code into the GrantedAbilities array on the component, or into AbilitySet DataAssets.

Step 2: Add the Core Component

Add UFWGASCoreComponent to your character. Replace any manual attribute change delegates with the core component's events:

ASC->GetGameplayAttributeValueChangeDelegate(
    UFWAttributeSet::GetHealthAttribute())
    .AddUObject(this, &AMyChar::OnHealthChanged);

// In Blueprint: bind to OnHealthChange on the GAS Core Component
// Or in C++:
GASCoreComponent->OnHealthChange.AddDynamic(this, &AMyChar::HandleHealthChange);

Step 3: Replace Manual Input Binding

If you were manually binding Input Actions to ability activation:

void AMyChar::OnAttackPressed()
{
    ASC->TryActivateAbilityByClass(UGA_Attack::StaticClass());
}

Add UFWAbilityInputBindingComponent to your character and configure the InputAction field on the ability's FFWAbilityInputMapping entry. Input binding is handled automatically.

Step 4: Convert to AbilitySets (Optional)

Move groups of related abilities from per-component arrays to UFWAbilitySet DataAssets for better organization and reuse.

Step 5: Adopt Modular Base Classes (Optional)

Replace your character/controller/game mode base classes with the FW modular variants to enable GameFeature action support.

Future Migration Notes

When upgrading between major versions, this page will document:

  • Breaking API changes -- renamed or removed functions, changed signatures.
  • Component changes -- new required components, deprecated components.
  • AbilitySet schema changes -- new fields, deprecated properties.
  • Replication changes -- modifications to replicated properties.
  • Step-by-step upgrade instructions with before/after code examples.

Before Upgrading

Always follow these steps when upgrading the plugin:

  1. Back up your project (source control recommended).
  2. Read the Changelog for the target version.
  3. Review this migration guide for breaking changes.
  4. Update the plugin files.
  5. Regenerate project files (right-click .uproject > Generate Project Files).
  6. Build and resolve any compile errors using this guide.
  7. Test ability granting, input binding, combos, and replication in a PIE session.