README

A package for chain calling Laravel relationships. Some relationships return collections so can't be chained. This package provides a way to get past that.

Installation

Install with composer

composer require zerochip/laravel-lineage

Add the ServiceProvider to your providers array in config/app.php

'providers' => [
    // Other Service Providers

    Zerochip\LineageServiceProvider::class,
];

Quickstart

Add the lineage trait to your model

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;
use Zerochip\Lineage\LineageTrait

class Subject extends Model
{
    use LineageTrait;
}

For example to get a quizzes for a subject.

Without lineage we would have had to do this:

$subject = Subject::find(1);
$quizzes = [];

foreach ($subject->courses as $course) {

    foreach ($course->chapters as $chapter) {

        foreach($chapter->topics as $topic) {

            foreach($topic->sections as $section) {
               
                $quizzes = $quizzes->merge($section->quizzes);
            }
        }
    }
}

Using Laravel-Lineage we just do the following

$subject = Subject::find(1);
$quizzes = $subject->lineage('courses->chapters->topics->sections->quizzes');

You can also get the lineage for a collection.

$subjects = Subject::get();
$quizzes = $subjects->lineage('courses->chapters->topics->sections->quizzes');

We can even get the inverse of that

$quiz = Quiz::find(1);
$subject = $quiz->lineage('section->topic->chapter->course->subject')->first();

NB: lineage always returns a collection hence the use of first in the above

Lineage format

Lineage format rules are as follows:

1. Uses the delimiter ->.

2. Should be a string

   $subject->lineage('course->chapters');
   
   // the following won't work
   $subject->lineage(course->chapters);

3. Should have at least 2 levels

   $subject->lineage('course->chapters');
   
   // the following will cause an error
   $subject->lineage('course');

4. If preferred can start with ->

   $subject->lineage('course->chapters');
   
   // produces the same result as above
   $subject->lineage('->course->chapters');

5. Can not be open ended

   $subject->lineage('course->chapters');
   
   // the following will cause an error
   $subject->lineage('course->chapters->');

Usage without trait and collection macro

The lineage class can be used directly. This class has one static method get() which takes the object (model or collection) as the first parameter and the lineage as the second

use Zerochip\Lineage;

$subject = Subject::find(1);
$topics = Lineage::get($subject, 'course->chapters->topics');

// The same with a collection
$courses = Courses::get();
$sections = Lineage::get($courses, 'chapters->topics->sections');