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Helpers Class (Code Reference)

The Helpers class is the central utility component of the School Enrollment System.
It provides shared logic for validation, login, menu handling, enrollment operations, reporting, and safe input handling.

This page documents the structure and responsibilities of the class in a clean, readable format.

Class Overview

The Helpers class contains:

  • Input validation methods
  • Login and authentication logic
  • Menu printing methods
  • Field‑updating utilities
  • Enrollment helpers
  • Reporting and statistics helpers
  • Safe integer input handling

It acts as the backbone of all workflows.

Login System

Method: loginUser

A generic login method used by:

  • Students
  • Instructors
  • Administrators

Workflow:

  1. Prompt for ID
  2. Prompt for password
  3. Search the appropriate list in dataManager
  4. Validate credentials
  5. Return the matching user object or null

This method ensures consistent authentication across all roles.

The class includes methods to print:

  • Student menu
  • Instructor menu
  • Administrator menu

Each menu is displayed after successful login and drives the workflow logic.

Safe Integer Input

Method: getSafeIntInput

Prevents crashes caused by invalid numeric input.

Behavior:

  • Wraps input in a try‑catch block
  • Catches InputMismatchException
  • Clears the scanner buffer
  • Repeats until a valid integer is entered

This method is used throughout all workflows.

Validation Methods

The class centralizes all validation logic.

Password Validation

Checks:

  • Minimum length
  • Non‑empty input

Email Validation

Checks:

  • Contains @
  • Contains .
  • Reasonable length

Phone Number Validation

Checks:

  • Exactly 10 digits
  • Numeric only

Address Validation

Checks:

  • Non‑empty
  • Minimum length

Name Validation

Checks:

  • Non‑empty
  • Alphabetic characters

These methods return true or false, allowing workflows to loop until valid input is provided.

Field Updating

Method: updateFieldWithPrompt

A generic method that uses a Predicate<String> to validate new field values.

Workflow:

  1. Prompt for new value
  2. Validate using predicate
  3. If valid, update the field
  4. If invalid, repeat

This eliminates repetitive validation code.

User Creation

Method: createUserWithPrompt

Used when creating:

  • Students
  • Instructors

Behavior:

  • Prompts for each required field
  • Validates using predicates
  • Returns the validated value

This ensures all new users are created with valid data.

Enrollment Helpers

The class includes methods to support student enrollment.

Method: enrollStudentInCourse

Validates:

  • Course is open
  • Course is not full
  • Student has enough credit hours
  • Student is not already enrolled

If valid:

  • Adds course to student
  • Adds student to course

Method: dropCourse

Validates:

  • Student is enrolled
  • Course is open

If valid:

  • Removes course from student
  • Removes student from course

These helpers ensure consistent enrollment logic.

Grade Viewing Helpers

The class provides methods to support the Assessment class:

  • View all grades for a course
  • View specific exam scores
  • View average grade

These methods guide user interaction and input selection.

Reporting Helpers

The class includes:

viewEnrollmentStatistics

Displays:

  • Total enrolled students
  • Whether open courses exist
  • Enrollment distribution

generateReports

Identifies:

  • Most popular course

These methods support administrative reporting.

Summary

The Helpers class is the utility engine of the School Enrollment System.
By centralizing validation, login, menu handling, enrollment logic, and reporting, it ensures consistency and reduces duplication across all workflows.

This class is essential for maintaining clean, organized, and reliable system behavior.