The "Wait For Condition" System

This feature is present in release v30 onwards.

This is a simple system to allow people to wait for conditions, and mark when they have been met or updated.

Each condition has a "name" - if you mark a condition with that name as "met", then any listeners of that condition name will be notified (and any subsequent users who listen to a condition that has already been met will be notified immediately).

You can also optionally include a generic object with a certain condition, e.g. if you want to wait for a certain actor to be ready, you can have a "OnActor[X]Ready" condition, and listeners will be informed both of when the actor is ready, and what the actor is.

Includes the following helper functions:

• WaitForCondition: A simple "wait for condition" - provide a condition name and a "On Condition Met" event, and it will trigger the event once the condition has been marked as done (via MarkConditionMet), or will trigger immediately if the condition has already been marked as done.

• WaitForCondition_WithResultObject: Same as "WaitForCondition", but will also provide a "Result Object" associated with the condition, in the "On Condition Met" event.

• ListenToConditionUpdates: Same as WaitForCondition_WithResultObject, but also listens to any subsequent updates to the "Result Object". (This will call the "On Condition Met" event immediately if the "Result Object" has already been provided via an earlier MarkConditionMet_WithResultObject, and then again every subsequent time)

• WaitForConditions: Same as WaitForCondition, but takes a list of condition names, and only triggers if/when they have all been met.

• MarkConditionMet: Call this to mark a condition as having been "met", triggering any listeners waiting on the condition.

• MarkConditionMet_WithResultObject: Same as MarkConditionMet, but provides a "Result Object". This will trigger any listeners waiting on the condition, or having its result object updated. NOTE: This can be called multiple times with the same condition name to update the current "Result Object" associated with that condition.

• GetMetConditions: Returns the list of all conditions that have been met so far

• HasMetCondition: Returns true if the provided condition name has been marked as "met"

• GetConditionResultObject: Returns the current object for the provided condition name.

An example of a "skins system", that provides the starting skin asset on BeginPlay (providing the condition with the SkinConditionName with the SkinAsset), and informs the condition system whenever the asset is updated.

Examples of listeners to the condition system - you can listen to updates of a condition, e.g. listening to whenever the SkinAsset from the earlier example updates, or listening to when multiple conditions have been marked as met, to implement a basic bootflow system.