README

Guard container object for dealing with optional/null values.

use Xtompie\Guard\Guard;

$user = Guard::of(request()->input('id'))
    ->filter(fn($id) => ctype_digit($id))
    ->map(fn($id) => User::find($id))
    ->not(fn() => abort(404))
    ->is(fn($user) => info("User found {$user->id}"))
    ->get();

Installation

Using composer

composer require xtompie/guard

Docs

Guard protects for calling methods on nulls values. The value might or might not be present. It has elegant fluent chaining syntax. No need for if/else statments and additional variables. Guard syntax is cleaner and more readable. Guard object is immutable.

Methods:

of - Creates guard
ofEmpty - Creates empty guard
is - Tells if value present or runs callback when value present
not - Same as is but negation
get - Gets raw value
getFn - Gets raw value with fallback callback
filter - Filter the value if present
reject - Same as filter but negation
map - Maps value if present
assert - Throw exception if value is not present
blank - Gets guard with provided value if current is not present
blankFn - Same as blank but with callback
let - Returns guard capture mechanism for nested properties, calls, array offsets

More info in source Guard.php

Usage

NoValueException

use Xtompie\Guard\Guard;

Guard::of(null)->assert()->get(); // NoValueException will be thrown

Default value

use Xtompie\Guard\Guard;

echo Guard::of(null)->get('default'); // -> default

Complex type and value

use Xtompie\Guard\Guard;

function divide($a, $b) {
    $b = Guard::of($b)
        ->map(fn($i) => (int)$i)
        ->reject(fn($i) => $i === 0)
        ->assert(\UnexpectedValueException::class)
        ->get();
    return $a / $b;
}

Let

let() Returns Let object. Offset get, property get, method call can be called on Let. After that operation new Guard with operation result will be returned. When offset, property, method not exist, empty Guard will be returned.

use Xtompie\Guard\Guard;

$options = [
    'a' => 'A',
    'b' => 'B',
];
$key = 'c';
echo Guard::of($options)->let()[$key]->get();

use Xtompie\Guard\Guard;

echo Guard::of(new \stdClass())
    ->let()->nonExistingMethod()
    ->let()->nonExistingProperty
    ->let()['nonExistingOffset']
    ->get('Undefined')
;

Extending

namespace MyApp\Util;

use Xtompie\Guard\Guard as BaseGuard;

class Guard extends BaseGuard
{
    public function or404()
    {
        $this->not(fn() => abort(404));
    }

    public function reject0()
    {
        return $this->reject(fn($i) => $i === 0);
    }
}

echo gettype(Guard::of(0)->reject0()->get());

xtompie / guard

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