Advanced Customization > Business Logic Customization > Windchill ProjectLink Customization > Writing Custom Windchill ProjectLink Algorithms > Supported APIs for Activity Calculation
  
Supported APIs for Activity Calculation
The following APIs are supported.
You can find additional information in the Windchill Javadoc.
* 
The EPPCustomUtils.java class provides helper APIs to retrieve data based on certain inputs.
PlannableHelper.service.getLeafActivitiesForSummary(plannable)
Returns WTCollection of individual activities (leaf activities) for a given summary or plan object.
AssignmentHelper.service.getResourceAssignmentsForPlannables(plannables)
Returns WTCollection of resource assignments for the given plan object.
PlanHelper.service.getPlansFromSummaryActivities(plannables)
Returns WTCollection of plans for a given set of activities.
PlanHelper.service.getProjectsForPlans(plans)
Returns WTHashSet of projects for a given list of plans.
PlanHelper.service.getSummaryActivities(plans,false)
Returns WTHashMap of summary activities. The key lists any child activities.