Extended Attributes

The BP_BaseExtendedAttribute class in the Advanced Attributes System provides a framework for adding custom functionality to attributes managed by the BP_AttributesComponent. It enables developers to implement project-specific logic, such as triggering events when an attribute reaches a threshold (e.g., death when health is zero) or managing regeneratable attributes. This class addresses the need for extensible attribute behavior in Action RPGs, allowing seamless integration with the attribute system without modifying core functionality.

Basic Usage

The BP_BaseExtendedAttribute is used by creating child classes and adding them to the ExtendedAttributes array of BP_AttributesComponent. Below are the primary methods for interacting with it in Blueprints.

1. OnAttributeValueModified:

   • Purpose: Responds to changes in the associated attribute’s value.
   • Usage: Override in a child Blueprint to implement custom logic when the attribute is modified.

2. OnCurrentAttributeValueUpdated:

   • Purpose: Reacts to updates to the associated attribute’s current value.
   • Usage: Override in a child Blueprint to handle value updates (e.g., UI or gameplay effects).

3. AddExtendedAttribute:

   • Purpose: Adds an instance of BP_BaseExtendedAttribute to an actor’s BP_AttributesComponent.
   • Usage: Call on BP_AttributesComponent to register the extended attribute.

Note:

Extended Attributes can also be added to default extended attributes array in the actors Attributes Component. If using attributes with Advanced ARPG Combat, the attributes array will need to be edited within the Player Info Data Asset or Enemy Info Data Asset

Key Properties

Property Name	Purpose
ExtendedAttributeTag	The Gameplay Tag linking the extended attribute to an attribute (e.g., Attribute.Health).
MaxAttributeTag	The Gameplay Tag of the max attribute for reference, used in derived classes like BP_BaseRegeneratableAttribute (e.g., Attribute.HealthMax).

Key Concepts

Custom Attribute Logic

The BP_BaseExtendedAttribute allows developers to define custom behavior for attributes, such as triggering abilities or updating systems when an attribute changes. This is achieved by overriding event functions like OnAttributeValueModified in child Blueprints.

• Purpose: Extends attribute functionality for project-specific needs.
• Usage: Create a child Blueprint and implement logic in OnAttributeValueModified.
• Benefit: Provides flexibility without altering the core attribute system.

Modular Attribute Behavior

• Purpose: Keeps logic isolated per attribute, avoiding bloated character Blueprints.
• Usage: Add multiple extended attributes to support unique logic for each stat.
• Benefit: Improves maintainability and code reusability.

Foundation for Regeneratable Attributes

The BP_BaseExtendedAttribute serves as the parent class for BP_BaseRegeneratableAttribute, enabling attributes like stamina to regenerate. This makes it a versatile base for both custom and specialized attribute behaviors.

• Purpose: Provides a reusable foundation for advanced attribute features.
• Usage: Derive new Blueprints from BP_BaseExtendedAttribute for custom or regeneratable attributes.
• Benefit: Streamlines development of complex attribute mechanics.

Best Practices

• Workflows:
  • Create specific child Blueprints (e.g., BP_HealthExtendedAttribute) for each attribute requiring custom logic.
  • Add extended attributes to PlayerInfoDataAsset or EnemyInfoDataAsset for centralized management in Advanced ARPG Combat projects.
• Pitfalls to Avoid:
  • Don’t skip setting ExtendedAttributeTag, as it links the extended attribute to the correct F_Attribute.
  • Avoid complex logic in OnAttributeValueModified to prevent performance bottlenecks.
• Performance Considerations:
  • Limit the number of ExtendedAttributes per actor to reduce processing overhead.
  • Cache frequently accessed attribute values in Blueprints to optimize event handling.