Just some random gist, a demonstration of "return $this" pattern

StudentChecklist.php

<?php

namespace DeltaX\Aegis\ModelServices\GradesRegistry;

use DeltaX\Aegis\MenuServices\Checklist;
use Carbon\Carbon;
use DeltaX\Utilities as U;

class StudentChecklist extends Checklist {

	/**
	 * $student
	 * @var \DeltaX\Models\Student
	 */

	protected $student;

	/**
	 * columns
	 * @var array
	 */

	protected $columns = [
		'courses.code',
		'courses.name',
		'courses.credits_in_lecture',
		'courses.credits_in_lab',
		'curricula.lec_contact_hrs',
		'curricula.lab_contact_hrs',
		'curricula.is_nth_yr_standing',
		'curriculum_terms.year_level',		
		'instructor.first_name',
		'instructor.last_name',
		'semester_attended.date_start',
		'semester_attended.part_number',
		'semester_attended.division_type',
		'enrolled_courses.final_grade',
		'remarks.remark'
	];

	/**
	 * setDegree
	 * @param string $code
	 * @return self
	 */
	public function setStudent(string $studentNumber) {
		$student = $this->repoInvoker->find('student', $studentNumber);
		if (empty($student)){
			throw new InvalidStudentNumberException;
		}

		$this->student = $student;
		$this->searchFilter['student_id'] = ['enrolled_courses.student_id', '=', $this->student->id];
		return $this;
	}

	/**
	 * runQuery
	 * @return \Illuminate\Database\Eloquent\Collection|null
	 */
	protected function prepareQuery() {

		$this->repoInvoker->entity('curricula', function($entity){

			return $entity
				->selectRaw('GROUP_CONCAT(prerequisite_courses.code) AS prerequisite')
				->join('courses', 'curricula.course_id', '=', 'courses.id')
				->join('curriculum_terms', 'curricula.curriculum_term_id', '=', 'curriculum_terms.id')
				->leftJoin('curriculum_prerequisites', 'curriculum_prerequisites.dependent_id', '=', 'curricula.id')
				->leftJoin('curricula AS prerequisites', 'curriculum_prerequisites.prerequisite_id', '=', 'prerequisites.id')
				->join('courses AS prerequisite_courses','curricula.course_id', '=', 'prerequisite_courses.id')
				->leftJoin('enrolled_courses', 'enrolled_courses.curriculum_id', '=', 'curricula.id')
				->join('term_attendance', 'enrolled_courses.term_attendance_id', '=', 'term_attendance.id')
				->join('school_calendar AS semester_attended', 'term_attendace.school_calendar_id', '=', 'semester_attended.id')
				->leftJoin('remarks', 'enrolled_courses.remark_id', '=', 'remarks.id')
				->leftJoin('course_sessions', 'enrolled_courses.course_session_id', '=', 'course_sessions.id')
				->leftJoin('employees', 'course_sessions.employee_id', '=', 'employees.id')
				->leftJoin('users AS instructors', 'employees.user_id', '=', 'instructors.id')
				->groupBy('curricula.id');

		})->where($params);

		return $this;

	}

	protected function runQuery(){
		$this->outputData = $this
			->prepareTermFilter()
			->prepareYearLevelFilter()
			->repoInvoker
			->get();

		return $this;
	}

	protected function createInstructorColumn($collection){
		$this->outputData = $collection->map(function ($item){
			$initial = substr($item['first_name'], 0, 1) . '.';
			$item['instructor'] = $initial . ' ' . $item['last_name'];
			unset($item['first_name']);
			unset($item['last_name']);

			return $item;
		});

		return $this;
	}

	protected function createTermTakenColumn($collection){

		$termTypes = [
			'Semester' => 6,
			'Trimester' => 4,
			'Quarter' => 3
		];

		$this->outputData = $collection->map(function ($item) use ($termTypes) {

			$partNumber = $item['part_number'];
			$numberOfMonths = $termTypes[$item['division_type']];

			$subtrahend = ($part_number == 1) ?
				0 : ($partNumber * $numberOfMonths);

			$yearStart = Carbon::parse($item['date_start'])
				->subMonth($subtrahend)->year;

			$yearEnd = $yearStart + 1;
			$nthTerm = U\ordinal($item['part_number']);

			//(e.g. 2nd, 2012-2013)
			$item['term_taken'] = $nthTerm . ', ' . $yearStart . '-' .$yearEnd;

			unset($item['part_number']);
			unset($item['division_type']);
			unset($item['date_start']);

			return $item;
		});

		return $this;
	}

	public function getData(){

		$this
			->createPrerequisiteColumn()
			->createInstructorColumn()
			->createTermTakenColumn();

		return $this;
	}

}