In this talk, Stephen talks about working with Eloquent in a manner that it helps you build world class applications

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 = AppDeveloper::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 = AppDeveloper::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 IlluminateDatabaseEloquentScope;
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 IlluminateSupportCollection;
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 = AppDeveloper ::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 = AppUser::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 AppMeetup;
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 AppMeetup;
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('AppContact');
}
}
RELATIONSHIPS ‐ 1‐1

53. Defining the other side
class Contact extends Model
{
public function user()
{
return $this‐>belongsTo('AppUser');
}
}
RELATIONSHIPS ‐ 1‐1

54. $user = AppUser::find(1);
// Instead of
$contact = AppContact::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('AppContact');
}
}
RELATIONSHIPS ‐ 1‐n

58. Defining the other side
class Contact extends Model
{
public function user()
{
return $this‐>belongsTo('AppUser');
}
}
RELATIONSHIPS ‐ 1‐n

59. RELATIONSHIPS ‐ 1‐n
$user = AppUser::find(1);
// Instead of
$contacts = AppContact::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('AppType')
‐>withPivot('id', 'value');
}
}
RELATIONSHIPS ‐ n‐n

63. Defining the other side
class Type extends Model
{
public function users()
{
return $this‐>belongsToMany('AppUser');
}
}
RELATIONSHIPS ‐ n‐n

64. RELATIONSHIPS ‐ 1‐n
// Instead of
$contacts = AppContact::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('AppPost', 'AppComment);
}
}
RELATIONSHIPS ‐ distant

68. // Instead of
$comments = AppComment::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
$users = AppUser::all();
foreach ($users as $user) {
echo $user‐>contact‐>phone;
}
// We do this
$user = AppUser::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