Enrollee Count

These functions provide comprehensive enrollment statistics for courses and projects, including both enrolled and completed participants across different policies and aliases.

enrolleeCount(core, policies)

Retrieves enrollment and completion statistics for a set of policies.

Signature

export async function enrolleeCount(core: Core, policies: string[]): Promise<{
  policy: string;
  state: string;
  enrolled: number;
  completed: number;
}[]>

Parameters

Returns

A promise that resolves to an array of objects, each containing:

• policy: The policy ID
• state: "Course" or "Project" (based on the state type)
• enrolled: Number of enrolled participants
• completed: Number of participants who completed the course/project

Behavior

1. Fetches completion data: Uses aliasesWhoCompletedByPolicies to get aliases that completed local states for the given policies.
2. Retrieves instance addresses: Gets all instance UTXOs and filters addresses by state:
   • ContributorStateScripts (for projects)
   • CourseStateScripts (for courses)
   • AssignmentValidator (for courses)
3. Counts enrollments:
   • For projects (ContributorStateScripts): Counts unique assets across UTXOs
   • For courses (CourseStateScripts/AssignmentValidator): Counts total UTXOs
4. Maps completion data: Associates completion counts with each policy from the earlier fetch.

State Mapping

• ContributorStateScripts → Project
• CourseStateScripts → Course
• AssignmentValidator → Course

Errors

Throws SdkError if:

• Failed to fetch completed local states
• Any other error occurs during processing

aliasesWhoCompletedByPolicies(core, policies)

Helper function that identifies which aliases have completed local states for given policies.

Signature

export async function aliasesWhoCompletedByPolicies(core: Core, policies: string[]): Promise<{
  policy: string;
  aliases: string[];
}[] | undefined>

Parameters

Returns

A promise that resolves to an array of objects containing:

• policy: The policy ID
• aliases: Array of alias names that completed states for this policy

Returns undefined if no completed states are found.

Behavior

1. Calls CompletedLocalStates to get all aliases with completed states.
2. For each policy, filters aliases that have completed local states matching that policy.
3. Returns the mapping of policies to their completing aliases.

CompletedLocalStates(core)

Internal helper function that retrieves all aliases with completed local states from the global state.

Signature

export async function CompletedLocalStates(core: Core): Promise<{
  alias: string;
  completedStates: any[];
}[] | undefined>

Parameters

Returns

A promise that resolves to an array of objects containing:

• alias: The alias name
• completedStates: Array of completed local state data (filtered for tag 121)

Returns undefined if no global state UTXOs are found.

Behavior

1. Fetches global state UTXOs.
2. Extracts datum information for each alias.
3. Filters credentials to only include completed states (tag 121).
4. Returns the processed data structure.

Examples

Basic Usage

// Get enrollment stats for specific policies
const policies = ["policy1", "policy2"];
const stats = await enrolleeCount(core, policies);
 
console.log(stats);
// Output:
// [
//   {
//     policy: "policy1",
//     state: "Course", 
//     enrolled: 25,
//     completed: 18
//   },
//   {
//     policy: "policy2",
//     state: "Project",
//     enrolled: 12, 
//     completed: 8
//   }
// ]

Check Completions Only

// Get just the completion data
const completions = await aliasesWhoCompletedByPolicies(core, policies);
 
console.log(completions);
// Output:
// [
//   {
//     policy: "policy1",
//     aliases: ["alice", "bob", "charlie"]
//   },
//   {
//     policy: "policy2", 
//     aliases: ["dave", "eve"]
//   }
// ]

Notes

• Unique Asset Counting: For projects, the system counts unique assets rather than total UTXOs to avoid double-counting participants with multiple contributions.
• State Detection: The function automatically detects whether a policy represents a course or project based on the instance state types found.
• Completion Tracking: Completion is tracked through global state entries with specific plutus data tags (tag 121).
• Error Handling: Returns empty arrays and logs errors for individual failures, but throws SdkError for critical failures.