I was moved to the feature "Higher Order Messages" in Laravel added at 5.4.

https://laravel.com/docs/5.5/collections#method-flatmap

I would like to show some examples.

Prerequisite

There are two models Company and User.

The obvious relationship is:

• Company hasMany Users
• User belongsTo Company

Company Model has these methods:

• getIsContractExpiredAttribute
• notifyContractExpiration

(This example has some problems but this is for just example)

Then we will take 5 contract expired companies randomly and send emails to those companies.

Before (~ 5.3)

Company::with('users')
    ->all()
    ->filter(function ($company) {
        return $company->isContractExpired;
    })
    ->take(5)
    ->pluck('users')->flatten()
    ->each(function ($user) {
        $user->notifyContractExpiration;
    });

After (5.4 ~)

Company::with('users')
    ->all()
    ->filter->isContractExpired
    ->take(5)
    ->flatMap->users
    ->each->notifyContractExpiration;

There are less closure. Simple, great readability.

Detail

In the above example, Company::all()->map returns Illuminate\Support\HigherOrderCollectionProxy which has a lot of tasks.

The following methods support HigherOrderCollectionProxy.

• average
• avg
• contains
• each
• every
• filter
• first
• flatMap
• map
• partition
• reject
• sortBy
• sortByDesc
• sum

For example, Company::all()->sum->isContractExpired returns count of contract expired companies.

A lot of fun like SQL, right?