Method chaining (or fluent expressions) for any value using any method.
- Requirements
- How to install
- How to use
- What does it solve?
- Notes
- License
- Change log
- Testing
- Contributing
- Security
- Credits
- About
- PHP 8.1 or 8.2
Via Composer:
composer require sebastiaanluca/php-pipe-operator
The basic gist of the package is that it takes a value and performs one or more actions on it. A simple example:
use SebastiaanLuca\PipeOperator\Pipe;
Pipe::from('hello')->strtoupper()->get();
// "HELLO"
A few alternatives to create the same instance:
take('hello')->strtoupper()->get();
// "HELLO"
pipe('hello')->strtoupper()->get();
// "HELLO"
Of course that's not very useful since you could've just used strtoupper('hello')
and be done with it, but the goal is to make multi-method calls on a value easier to read and write:
$subdomain = Pipe::from('https://blog.sebastiaanluca.com')
->parse_url()
->end()
->explode('.', PIPED_VALUE)
->reset()
->get();
// "blog"
Note that in comparison to the original RFC, there's no need to pass the initial value to methods that receive the value as first parameter and have no other required parameters. The previous value is always passed as first parameter. In effect, both of the following examples will work:
Pipe::from('hello')->strtoupper()->get();
// "HELLO"
Pipe::from('hello')->strtoupper(PIPED_VALUE)->get();
// "HELLO"
In contrast, if a method takes e.g. a setting before the previous value, we need to set it manually using the replacement identifier (the globally available PIPED_VALUE
constant). This identifier can be placed anywhere in the method call, it will simply be replaced by the previous value.
Pipe::from(['key' => 'value'])
->array_search('value', PIPED_VALUE)
->get();
// "key"
Since PHP 8.1, you can use a first class callable syntax, or simply put an anonymous function, to pipe the value through. This enables full method autocompletion.
take('STRING')
->pipe(strtolower(...))
->get()
// "string"
Or using parameters:
Pipe::from('https://sebastiaanluca.com/blog')
->pipe(parse_url(...))
->end()
->pipe(substr(...), PIPED_VALUE, 3)
->pipe(strtoupper(...))
->get(),
// "OG"
Sometimes standard methods don't cut it and you need to perform a custom operation on a value in the process. You can do so using a closure:
Pipe::from('string')
->pipe(fn(string $value): string => 'prefixed-' . $value)
->get();
// "prefixed-string"
The same is possible using a class method (regardless of visibility):
class MyClass
{
public function __construct()
{
Pipe::from('HELLO')
->pipe($this)->lowercase()
->get();
// "hello"
}
/**
* @param string $value
*
* @return string
*/
private function lowercase(string $value) : string
{
return mb_strtolower($value);
}
}
If you don't want to use the internal pipe proxy and pass $this
, there are two other ways you can use class methods.
Using first class callable syntax:
class MyClass
{
public function __construct()
{
Pipe::from('HELLO')
->pipe($this->lowercase(...))
->get();
// "hello"
}
/**
* @param string $value
*
* @return string
*/
public function lowercase(string $value) : string
{
return mb_strtolower($value);
}
}
Using an array (for public methods only):
class MyClass
{
public function __construct()
{
Pipe::from('HELLO')
->pipe([$this, 'lowercase'])
->get();
// "hello"
}
/**
* @param string $value
*
* @return string
*/
public function lowercase(string $value) : string
{
return mb_strtolower($value);
}
}
By parsing the callable method to a closure:
use Closure;
class MyClass
{
public function __construct()
{
Pipe::from('HELLO')
->pipe(Closure::fromCallable([$this, 'lowercase']))
->get();
// "hello"
}
/**
* @param string $value
*
* @return string
*/
private function lowercase(string $value) : string
{
return mb_strtolower($value);
}
}
This package is based on the pipe operator RFC by Sara Golemon (2016), who explains the problem as:
A common PHP OOP pattern is the use of method chaining, or what is also known as “Fluent Expressions”. […] This works well enough for OOP classes which were designed for fluent calling, however it is impossible, or at least unnecessarily arduous, to adapt non-fluent classes to this usage style, harder still for functional interfaces.
Coming across the proposal, I also blogged about it.
Say you want to get the subdomain from a URL, you end up with something like this:
$subdomain = 'https://blog.sebastiaanluca.com/';
$subdomain = parse_url($subdomain, PHP_URL_HOST);
$subdomain = explode('.', $subdomain);
$subdomain = reset($subdomain);
// "blog"
This works, of course, but it's quite verbose and repetitive.
Same result, different style:
$subdomain = explode('.', parse_url('https://blog.sebastiaanluca.com/', PHP_URL_HOST))[0];
// "blog"
This might be the worst of all solutions, as it requires you to start reading from the center, work your way towards the outer methods, and keep switching back and forth. The more methods and variants, the more difficult to get a sense of what's going on.
See Sara's RFC for more complex and real-world examples.
While this packages makes a good attempt at bringing the pipe operator to PHP, it unfortunately does not offer autocompletion on chained methods. For that to work we need the real deal, so make some noise and get the people in charge to vote for Sara's RFC!
This package operates under the MIT License (MIT). Please see LICENSE for more information.
Please see CHANGELOG for more information what has changed recently.
composer install
composer test
Please see CONTRIBUTING and CONDUCT for details.
If you discover any security related issues, please email [email protected] instead of using the issue tracker.
My name is Sebastiaan and I'm a freelance Laravel developer specializing in building custom Laravel applications. Check out my portfolio for more information, my blog for the latest tips and tricks, and my other packages to kick-start your next project.
Have a project that could use some guidance? Send me an e-mail at [email protected]!