Speaking Eloquent Eloquently

Getting the most out of your eloquent models.
Eloquent is an ORM, it is the default in Laravel applications

Transcript

1. SPEAKING ELOQUENT ELOQUENTLY
2. Stephen Afam‐Osemene https://stephenafamo.com @StephenAfamO
3. Thinking Eloquently Accessors & Mutators Scopes Collections Serialization Events & Observers Relationships Mutators OUTLINE
4. THINKING ELOQUENTLY
5. THINKING ELOQUENTLY Eloquent is not just a fancy way of specifying the table for the Query Builder
6. A Model, should enable us retrieve and manipulate EVERY information related to it THINKING ELOQUENTLY
7. Data manupulation belongs in the Model A model should completely define a unit of DATA THINKING ELOQUENTLY
8. ACCESSORS & MUTATORS
9. ACCESSORS Accessors allow us to format our data when we retrieve them
10. Instead of ACCESSORS $user = User::find(1); echo "http://myapp.com" . $user‐>avatar;
11. ACCESSORS We do class User extends Model { public function getAvatarAttribute($value) { return "http://myapp.com/" . $value; } }
12. MUTATORS Mutators allow us to format our data when we set them
13. Instead of $user‐>name = ucfirst("stephen"); MUTATORS
14. We do class User extends Model { public function setNameAttribute($value) { $this‐>attributes['name'] = ucfirst($value); } } MUTATORS
15. SCOPES
16. SCOPES Scopes are ways for us to store restraints which we can use repeatedly
17. SCOPES ‐ LOCAL Local scopes are specific to the model. Although, we can always extend the class ;‐﴿
18. SCOPES ‐ LOCAL Do this once class Developer extends Model { public function scopeSenior($query) { return $query‐>where('yrs_of_exp', '>', 3); } }
19. SCOPES ‐ LOCAL Use anytime! $senior_devs = App\Developer::senior()‐>get()
20. SCOPES ‐ LOCAL We can accept additional parameters to make our scopes dynamic
21. SCOPES ‐ LOCAL class Developer extends Model { public function scopeUses($query, $language) { return $query‐>where('language', $language); } } Make it dynamic
22. SCOPES ‐ LOCAL $php_devs = App\Developer::uses('php)‐>get() Use anytime!
23. SCOPES ‐ GLOBAL We can define a scope that will be applied to all queries by our Model
24. SCOPES ‐ GLOBAL use Illuminate\Database\Eloquent\Scope; class VerifiedScope implements Scope { public function apply($builder, $model) { $builder‐>where('verified', true); } } Define the scope
25. class Developer extends Model { protected static function boot() { parent::boot(); static::addGlobalScope(new VerifiedScope); } } SCOPES ‐ GLOBAL Include the scope
26. SCOPES ‐ GLOBAL Now all queries from our Developer model will retrieve only verified entries.
27. SCOPES ‐ GLOBAL // Global scope automatically applied $verified_devs = Developer::get() // Query without the Verified global scope Developer::withoutGlobalScope(VerifiedScope::class)‐>get() // Query without any global scope Developer:: withoutGlobalScopes()‐>get() Define the scope
28. COLLECTIONS
29. COLLECTIONS Anytime multiple records are retrieved, it is returned as a COLLECTION of Models
30. COLLECTIONS Collections are supercharged php arrays. learn about it https://laravel.com/docs/5.4/collections
31. COLLECTIONS We can define a custom Collection Object to be returned by our model.
32. COLLECTIONS use Illuminate\Support\Collection; class CustomCollection extends Collection { public function additionalMethod($var) { // do something unique } } Define our new collection class
33. COLLECTIONS Overwrite the newCollection method class Developer extends Model { public function newCollection(array $models = []) { return new CustomCollection($models); } }
34. SERIALIZATION
35. SERIALIZATION We can easily convert our Model into an array or JSON of it's attributes
36. SERIALIZATION Easy! $developer = App\Developer ::find(1); // For arrays $developer_array = $develooper‐>toArray(); // For JSON $developer_json = $developer‐>toJson()
37. Sometimes we need to hide stuff so... SERIALIZATION class User extends Model { protected $hidden = ['age', 'address']; // OR protected $visible = ['company', 'name']; }
38. Other times we want to access hidden stuff so... SERIALIZATION $user = App\User::find(1); // maybe when the user is viewing $with_age = $user‐>makeVisible('age')‐>toArray(); // for corporate reasons maybe ˉ\_(ツ)_/ˉ $without_company = $user‐>makeHidden('company')‐>toArray;
39. What if we just want to add stuff? SERIALIZATION class User extends Model { protected $appends = ['birth_year']; public function getIBirthYearAttribute() { return date("Y") ‐ $this‐>age; } }
40. EVENTS & OBSERVERS
41. EVENTS & OBSERVERS Laravel events are a great way to subscribe and listen for various events that occur in our application. https://laravel.com/docs/5.4/events
42. EVENTS & OBSERVERS Eloquent models fire several events. We can map these events to our event classes
43. EVENTS & OBSERVERS Define the events property to map events class User extends Model { protected $events = [ 'saved' => UserSaved::class, 'deleted' => UserDeleted::class, ]; }
44. EVENTS & OBSERVERS Full list of Eloquent events creating created updating updated saving saved deleting deleted restoring restored
45. EVENTS & OBSERVERS Observers are classes whose sole purpose is to listen to eloquent events
46. EVENTS & OBSERVERS Create the Observer class use App\Meetup; class MeetupObserver { public function saving (Meetup $meetup) { // do something for the 'saving' event // you an have more functions with 'event' names } }
47. EVENTS & OBSERVERS Register the observer in a ServiceProvider use App\Meetup; class MyServiceProvider { public function boot () { Meetup::observe(MeetupObserver::class); } }
48. RELATIONSHIPS
49. RELATIONSHIPS Eloquent makes is really easy to define and access related models
50. RELATIONSHIPS ‐ 1‐1 One‐to‐One relationships are where each model is tied to one of the other type
51. users id ‐ integer name ‐ string contact id ‐ integer user_id ‐ integer phone ‐ string email ‐ string website ‐ string Example Database schema RELATIONSHIPS ‐ 1‐1
52. Defining one side of the relationship class User extends Model { public function contact() { return $this‐>hasOne('App\Contact'); } } RELATIONSHIPS ‐ 1‐1
53. Defining the other side class Contact extends Model { public function user() { return $this‐>belongsTo('App\User'); } } RELATIONSHIPS ‐ 1‐1
54. $user = App\User::find(1); // Instead of $contact = App\Contact::select('contacts.*') ‐>where('user_id', '=', $user‐>id) ‐>first(); // We do $contact = $user‐>contact; RELATIONSHIPS ‐ 1‐1
55. RELATIONSHIPS ‐ 1‐n One‐to‐Many relationships are where one model is linked to many of another type
56. Example Database schema users id ‐ integer name ‐ string contact id ‐ integer user_id ‐ integer type ‐ string value ‐ string RELATIONSHIPS ‐ 1‐n
57. Defining one side of the relationship class User extends Model { public function contacts() { return $this‐>hasMany('App\Contact'); } } RELATIONSHIPS ‐ 1‐n
58. Defining the other side class Contact extends Model { public function user() { return $this‐>belongsTo('App\User'); } } RELATIONSHIPS ‐ 1‐n
59. RELATIONSHIPS ‐ 1‐n $user = App\User::find(1); // Instead of $contacts = App\Contact::select('contacts.*') ‐>where('user_id', '=', $user‐>id) ‐>get(); // We do $contacts = $user‐>contacts;
60. RELATIONSHIPS ‐ n‐n Many‐to‐Many relationships are more complicated
61. Example Database schema users id ‐ integer name ‐ string contact id ‐ integer user_id ‐ integer type_id ‐ integer value ‐ string type id ‐ integer name ‐ string RELATIONSHIPS ‐ n‐n
62. Defining one side of the relationship class User extends Model { public function types() { return $this‐>belongsToMany('App\Type') ‐>withPivot('id', 'value'); } } RELATIONSHIPS ‐ n‐n
63. Defining the other side class Type extends Model { public function users() { return $this‐>belongsToMany('App\User'); } } RELATIONSHIPS ‐ n‐n
64. RELATIONSHIPS ‐ 1‐n // Instead of $contacts = App\Contact::select('contacts.*') ‐>join('types', 'contact.type_id', '=', 'types.id') ‐>where('user_id', '=', $user‐>id) ‐>where('type.name', '=', 'phone') ‐>get(); // We do $types = $user‐>types; //access throught the pivot property
65. RELATIONSHIPS ‐ distant Distant relations can be accessed easily by using the hasManyThrough﴾﴿ relationship
66. Example Database schema users id ‐ integer name ‐ string posts id ‐ integer user_id ‐ integer title ‐ string body ‐ string comments id ‐ integer post_id ‐ integer title ‐ string body ‐ string RELATIONSHIPS ‐ distant
67. Defining the relationship class User extends Model { public function comments() { return $this‐>hasManyThrough('App\Post', 'App\Comment); } } RELATIONSHIPS ‐ distant
68. // Instead of $comments = App\Comment::select('comments.*') ‐>join('posts', 'comment.post_id', '=', 'posts.id') ‐>join('users', 'post.user_id', '=', 'users.id') ‐>where('user_id', '=', $user‐>id) ‐>get(); // We do $comments = $user‐>comments; RELATIONSHIPS ‐ distant
69. RELATIONSHIPS ‐ morph Polymorphic relationships can save us from creating many similar tables.
70. RELATIONSHIPS ‐ morph We can allow more than one model to relate with our model. Many applications
71. Example Database schema users id ‐ integer name ‐ string groups id ‐ integer name ‐ string pictures id ‐ integer path‐ string owner_id ‐ integer owner_type ‐ string RELATIONSHIPS ‐ morph
72. RELATIONSHIPS ‐ notes Dynamic properties $post‐>comments; //get all comments as a collection $post‐>comments(); //returns a relationship class // Can be used as query builders $post‐>comments()‐>where('like', '>', 5);
73. RELATIONSHIPS ‐ notes Check if it exists Post::has('comments', '>=', 3)‐>get(); Post::doesntHave('comments')‐>get();
74. RELATIONSHIPS ‐ notes Eager Loading // Instead of this $users = App\User::all(); foreach ($users as $user) { echo $user‐>contact‐>phone; } // We do this $user = App\User::with('contact')‐>get();
75. Inserting & Updating create﴾﴿ save﴾﴿ associate﴾﴿ dissociate﴾﴿ attach﴾﴿ detach﴾﴿ sync﴾﴿ toggle﴾﴿ RELATIONSHIPS ‐ notes We have many ways to modify relationships
76. RELATIONSHIPS ‐ notes So many more lovely capabilities. https://laravel.com/docs/5.4/ eloquent‐relationships
77. QUESTIONS? Twitter: @StephenAfamO GitHub: @StephenAfamO Website: https://stephenafamo.com
78. THANK YOU Twitter: @StephenAfamO GitHub: @StephenAfamO Website: https://stephenafamo.com