Parameter

Summary

Parameter is a library around parameter-argument which provides additional functionality with validation rules and schema introspection.

Installing

Parameter is available through Packagist (opens new window) and the repository source is at chevere/parameter (opens new window).

composer require chevere/parameter

What it does?

Parameter enables to spawn dynamic parameters of any type with extra rules.

For example, an integer of minimum value 10.

use function Chevere\Parameter\int;

$int = int(min: 10);
$int($var); // exception if $var < 10

In function or method parameters you can use attributes to define validation rules for parameters and return value.

use Chevere\Parameter\Attributes\FloatAttr;
use Chevere\Parameter\Attributes\IntAttr;
use Chevere\Parameter\Attributes\ReturnAttr;
use function Chevere\Parameter\returnAttr;
use function Chevere\Parameter\validated;

#[ReturnAttr(
    new FloatAttr(min: 0, max: 2400)
)]
function wageWeekWA(
    #[IntAttr(min: 1628)]
    int $cents,
    #[FloatAttr(min: 0, max: 40)]
    float $hours
) {
    return $cents*$hours/100;
}
validated('wageWeekWA', $cents, $hours);

Validation can be triggered using validated (example above), inline and/or delegated to a caller wrapper. Parameter provides helpers to access rules for both parameters and return value to ease wiring process.

Rules defined by each parameter provide a human-readable schema which allows to expose the validation criteria.

How to use

Parameter provides an API which can be used to create parameters using functions and/or attributes. Parameter objects can be used directly in the logic while attributes requires a read step.

Inline usage

Use inline validation to go from this:

if($var > 10 || $var < 1) {
    throw new InvalidArgumentException();
}

To this:

use function \Chevere\Parameter\int;

int(min: 1, max: 10)($var);

Attribute-based usage

Use attributes to define rules for parameters and return value.

Use attribute delegated validation with the validated() function to go from this:

function myFunction(int $var): string
{
    if($var > 10 || $var < 1) {
        throw new InvalidArgumentException();
    }
    $return = 'done ok';
    return preg_match('/ok$/', $return)
        ? $return
        : throw new InvalidArgumentException();
}
$result = myFunction($var);

To this:

use Chevere\Parameter\Attributes\IntAttr;
use Chevere\Parameter\Attributes\ReturnAttr;
use Chevere\Parameter\Attributes\StringAttr;
use function Chevere\Parameter\validated;

#[ReturnAttr(
    new StringAttr('/ok$/')
)]
function myFunction(
    #[IntAttr(min: 1, max: 10)]
    int $var
): string
{
    return 'done ok';
}
$result = validated('myFunction', $var);

Use reflectionToParameters and reflectionToReturn functions for manual validation for arguments and return value:

use ReflectionFunction;
use function Chevere\Parameter\reflectionToParameters;
use function Chevere\Parameter\reflectionToReturn;

$reflection = new ReflectionFunction('myFunction');
$parameters = reflectionToParameters($reflection);
$return = reflectionToReturn($reflection);
$parameters(...$args); // valid $args
$result = myFunction(...$args); // myFunction call
$return($result); // valid $result

Use attribute inline validation for manual validation within the function body:

use Chevere\Parameter\Attributes\IntAttr;
use Chevere\Parameter\Attributes\ReturnAttr;
use Chevere\Parameter\Attributes\StringAttr;
use function Chevere\Parameter\valid;
use function Chevere\Parameter\returnAttr;

#[ReturnAttr(
    new StringAttr('/ok$/')
)]
function myFunction(
    #[IntAttr(min: 1, max: 10)]
    int $var
): string
{
    valid(); // valid $var
    $return = 'ok';

    return returnAttr()($return); // valid $return
}

CallableAttr

Attributes in PHP only support expressions you can use on class constants. Is not possible to directly define dynamic parameters using attributes.

To avoid this limitation you can use CallableAttr attribute which enables to forward parameter resolution to a callable returning a ParameterInterface instance.

use Chevere\Parameter\Interfaces\ParameterInterface;
use Chevere\Parameter\Attributes\CallableAttr;

function myCallable(): ParameterInterface
{
    return arrayp(
        email: string(),
    )->withOptional(
        name: string(),
    );
}

#[CallableAttr('myCallable')]

Parameter types

A Parameter is an object implementing ParameterInterface. There are several Parameter types, each one with its own validation rules. Every Parameter can define a description and a default value, plus additional validation rules depending on the type.

A Parameter can be defined using functions and/or attributes, it takes the same arguments for both.

When invoking a Parameter it will trigger validation against the passed argument.

String

Use function string to create a StringParameter. Pass a regex for string matching.

use function Chevere\Parameter\string;

// Any string
$string = string();
// String matching bin-<digits>
$string = string('/^bin-[\d]+$/');
$string('bin-123');

Use StringAttr attribute to define a string parameter.

use Chevere\Parameter\Attributes\StringAttr;

#[StringAttr('/^bin-[\d]+$/')]

String pseudo-parameters

The following parameters are based on String.

Enum string

Use function enum to create a StringParameter matching a list of strings.

use function Chevere\Parameter\enum;

$enum = enum('on', 'off');
$enum('on');
$enum('off');

Use EnumAttr attribute to define an enum string parameter.

use Chevere\Parameter\Attributes\EnumAttr;

#[EnumAttr('on', 'off')]

Int string

Use function intString to create a StringParameter matching a string integers.

use function Chevere\Parameter\intString;

$int = intString();
$int('100');

Bool string

Use function boolString to create a StringParameter matching 0 and 1 strings.

use function Chevere\Parameter\boolString;

$bool = boolString();
$bool('0');
$bool('1');

Date string

Use function date to create a StringParameter matching YYYY-MM-DD strings.

use function Chevere\Parameter\date;

$date = date();
$date('2021-01-01');

Time string

Use function time to create a StringParameter matching hh:mm:ss strings.

use function Chevere\Parameter\time;

$time = time();
$time('12:00:00');

Datetime string

Use function datetime to create a StringParameter matching YYYY-MM-DD hh:mm:ss strings.

use function Chevere\Parameter\datetime;

$datetime = datetime();
$datetime('2024-01-09 10:53:00');

Int

Use function int to create a IntParameter. Pass min and max values for integer range, accept for a list of accepted integers and reject for a list of rejected integers.

use function Chevere\Parameter\int;

// Any int
$int = int();
$int(1);
// Integer between 0 and 100
$int = int(min: 0, max: 100);
$int(50);
// Integer matching 1, 2 or 3
$int = int(accept: [1, 2, 3]);
$int(2);
// Integer not-matching 1, 2 or 3
$int = int(reject: [1, 2, 3]);
$int(4);

Use IntAttr attribute to define an integer parameter.

use Chevere\Parameter\Attributes\IntAttr;

#[IntAttr(min: 0, max: 100)]

Int pseudo-parameters

The following parameters are based on Int.

Bool int

Use function boolInt to create a IntParameter matching 0 and 1 integers.

use function Chevere\Parameter\boolInt;

$bool = boolInt();
$bool(0);
$bool(1);

Float

Use function float to create a FloatParameter. Pass min and max values for float range, accept for a list of accepted floats and reject for a list of rejected floats.

use function Chevere\Parameter\float;

// Any float
$float = float();
$float(1.5);
// Float between 0 and 100
$float = float(min: 0, max: 100);
$float(50.5);
// Float matching 1.5, 2.5 or 3.5
$float = float(accept: [1.5, 2.5, 3.5]);
$float(2.5);
// Float not-matching 1.5, 2.5 or 3.5
$float = float(reject: [1.5, 2.5, 3.5]);
$float(4.5);

Use FloatAttr attribute to define a float parameter.

use Chevere\Parameter\Attributes\FloatAttr;

#[FloatAttr(min: 0, max: 100)]

Bool

Use function bool to create a BoolParameter.

use function Chevere\Parameter\bool;

$bool = bool();
$bool(true);
$bool(false);

Use BoolAttr attribute to define a bool parameter.

use Chevere\Parameter\Attributes\BoolAttr;

#[BoolAttr]

Null

Use function null to create a NullParameter.

use function Chevere\Parameter\null;

$null = null();
$null(null);

Use NullAttr attribute to define a null parameter.

use Chevere\Parameter\Attributes\NullAttr;

#[NullAttr]

Object

Use function object to create a ObjectParameter. Pass a className for the object class name.

use function Chevere\Parameter\object;

$object = object(stdClass::class);
$object(new stdClass());

Use ObjectAttr attribute to define an object parameter.

use Chevere\Parameter\Attributes\ObjectAttr;

#[ObjectAttr(stdClass::class)]

Mixed

Use function mixed to create a MixedParameter.

use function Chevere\Parameter\mixed;

$mixed = mixed();
$mixed(1);
$mixed('1');
$mixed(true);
$mixed(null);

Union

Use function union to create a UnionParameter. Pass a list of parameters to match, target value must match at least one.

use function Chevere\Parameter\union;

// Any string or null
$union = union(string(), null());
$union('abc');
$union(null);
// Any digit string or any integer
$union = union(
    intString(),
    integer()
);
$union('100');
$union(100);

Array

Parameter for type array is handled as a composite Parameter holding parameter definition for each one of its members.

Use function arrayp to create an ArrayParameter for named arguments as required array keys.

use function Chevere\Parameter\arrayp;

// Empty array
$array = arrayp();
$array([]);
// Required 'a' => <string>
$array = arrayp(a: string());
$array(['a' => 'Hello world']);

Parameter supports nested arrays of any depth:

use function Chevere\Parameter\arrayp;
use function Chevere\Parameter\float;
use function Chevere\Parameter\int;

$array = arrayp(
    id: int(min: 0),
    items: arrayp(
        id: int(min: 0),
        price: float(min: 0),
    ),
);
$array([
    'id' => 1,
    'items' => [
        'id' => 25,
        'price' => 16.5,
    ]
]);

Use ArrayAttr attribute to define an array parameter.

use Chevere\Parameter\Attributes\ArrayAttr;
use Chevere\Parameter\Attributes\FloatAttr;
use Chevere\Parameter\Attributes\IntAttr;

#[ArrayAttr(
    id: new IntAttr(),
    items: new ArrayAttr(
        id: new IntAttr(),
        price: new FloatAttr(),
    ),
)]

With required

use method withRequired to define required parameters.

$array = $array
    ->withRequired(
        username: string(),
        email: string()
    );

With optional

use method withOptional to define optional parameters.

$array = $array
    ->withOptional(address: string());

👉 Note: Optional parameters will be validated only if a matching key is provided.

With modify

use method withModify to define modify parameters.

$array = $array
    ->withModify(
        username: string('/\w+/'),
    );

With make optional

use method withMakeOptional to make required parameters optional.

$array = $array
    ->withMakeOptional('username');

With make required

use method withMakeRequired to make optional parameters required.

$array = $array
    ->withMakeRequired('email');

Without

use method without to remove parameters.

$array = $array
    ->without('a');

With optional minimum

use method withOptionalMinimum to define a minimum number of optional parameters. Useful if all parameters are optional but 1.

$array = $array
    ->withOptionalMinimum(1);

Array pseudo-parameters

The following parameters are based on Array.

Array String

Use function arrayString to create an ArrayStringParameterInterface for string values. It only supports string parameters.

use function Chevere\Parameter\arrayString;
use function Chevere\Parameter\string;

$array = arrayString(
    test: string(),
);
$array(['test' => 'foo']);

File

Use function file to create an ArrayParameter for file uploads.

use function Chevere\Parameter\file;

$array = file();
$file = [
    'name' => 'foo.txt',
    'type' => 'text/plain',
    'tmp_name' => '/tmp/phpYzdqkD',
    'error' => 0,
    'size' => 123,
];
$array($file);

By default it provides validation for $_FILES shape, but you can define your own validation rules. For example, to validate name and contents:

use function Chevere\Parameter\file;

$array = file(
    name: string('/^\.txt$/'),
    contents: string('/wage-/'),
);
$array(
    'name' => 'wage-2024.txt',
    'type' => 'text/plain',
    'tmp_name' => '/tmp/phpYzdqkD',
    'error' => 0,
    'size' => 27,
    'contents' => 'yada yada wage-2024 bla bla',
);

Iterable

Iterable type Traversable|array is considered as a composite Parameter holding a generic definition for key and value. Parameter enables to describe this collection of items sharing the same shape.

Use function iterable to create an IterableParameter. Pass a V and K parameters for generic key and value.

use function Chevere\Parameter\int;
use function Chevere\Parameter\iterable;

$iterable = iterable(int(min: 0));
$iterable([0, 1, 2, 3]);

It also works with named keys:

use function Chevere\Parameter\int;
use function Chevere\Parameter\iterable;
use function Chevere\Parameter\string;

$iterable = iterable(
    V: arrayp(
        id: int(min: 0),
        name: string('^[\w]{1,255}'),
    )
    K: string(),
);
$iterable([
    'based' => [
        'id' => 1,
        'name' => 'OscarGangas'
    ],
    'fome' => [
        'id' => 2,
        'name' => 'BomboFica'
    ],
]);

Cookbook

Inline validation

• Validate string starting with "a":

use function Chevere\Parameter\string;

$value = 'ahhh';
string('/^a.+/')($value);

• Validate an int of min value 100:

use function Chevere\Parameter\int;

$value = 100;
int(min: 100)($value);

• Validate an int accept list:

use function Chevere\Parameter\int;

$value = 1;
int(accept: [1, 2, 3])($value);

• Validate a float reject list:

use function Chevere\Parameter\float;

$value = 3.1;
float(reject: [1.1, 2.1])($value);

• Validate an array:

use function Chevere\Parameter\arrayp;
use function Chevere\Parameter\int;
use function Chevere\Parameter\string;

$value = [
    'id' => 1,
    'name' => 'Pepe'
];
arrayp(
    id: int(min: 1),
    name: string('/^[A-Z]{1}\w+$/')
)($value);

• Validate an iterable int list:

use function Chevere\Parameter\int;
use function Chevere\Parameter\iterable;

$value = [1, 2, 3];
iterable(int())($value);

• Validate an iterable int list with string key type rules:

use function Chevere\Parameter\int;
use function Chevere\Parameter\iterable;

$value = [
    'unila' => 1,
    'dorila' => 2,
    'tirifila' => 3,
];
iterable(
    K: string('/ila$/'),
    V: int(min: 1)
)($value);

• Validate an union of type ?int:

use function Chevere\Parameter\int;
use function Chevere\Parameter\null;

$value = 1;
union(int(), null())($value);

Attribute delegated validation

• Use function validated() to get a return validated against all rules.

use function Chevere\Parameter\validated;

$result = validated('myFunction', $var);

• Use function reflectionToParameters() to get rules for validating arguments.

use ReflectionMethod;
use Chevere\Parameter\Attributes\IntAttr;
use function Chevere\Parameter\arguments;
use function Chevere\Parameter\reflectionToParameters;

$class = new class() {
    public function wea(
        #[IntAttr(accept: [1, 10, 100])]
        int $base
    ): void {
    }
};
$object = new $class();
$reflection = new ReflectionMethod($object, 'wea');
$parameters = reflectionToParameters($reflection);
$args = ['base' => 10];
$parameters(...$args); // valid $args
$result = $object->wea(...$args);

• Use function reflectionToReturn() to get rules for validating function/method return value:

use ReflectionFunction;
use Chevere\Parameter\Attributes\IntAttr;
use Chevere\Parameter\Attributes\ReturnAttr;
use function Chevere\Parameter\reflectionToReturn;

$function =
    #[ReturnAttr(
        new IntAttr(min: 1000)
    )]
    function (int $base): int {
        return 10 * $base;
    };
$reflection = new ReflectionFunction($function);
$return = reflectionToReturn($reflection);
$base = 10;
$result = $function($base);
$result = $return($result); // Validates result

Attribute inline validation

Use valid() on the function/method body to trigger validation for arguments.

• Validate an string enum for Hugo, Paco, Luis:
• Validate a min float value of 1000:

use Chevere\Parameter\Attributes\EnumAttr;
use function Chevere\Parameter\validate;

function myEnum(
    #[EnumAttr('Hugo', 'Paco', 'Luis')]
    string $name,
    #[FloatAttr(min: 1000)]
    float $money
): void
{
    valid();
    // Or single...
    valid('name');
    valid('money');
}
$arg1 = 'Paco';
$arg2 = 1000.50;
myEnum($arg1, $arg2);

• Validate an int of any value but 0 and 100:

use Chevere\Parameter\Attributes\IntAttr;
use function Chevere\Parameter\validate;

function myInt(
    #[IntAttr(reject: [0, 100])]
    int $id
): void
{
    valid();
}
$value = 50;
myInt($value);

• Validate a nasty nested array:

use Chevere\Parameter\Attributes\ArrayAttr;
use Chevere\Parameter\Attributes\IntAttr;
use Chevere\Parameter\Attributes\StringAttr;
use Chevere\Parameter\Attributes\IterableAttr;
use function Chevere\Parameter\validate;

function myArray(
    #[ArrayAttr(
        id: new IntAttr(min: 1),
        role: new ArrayAttr(
            mask: new IntAttr(accept: [64, 128, 256]),
            name: new StringAttr('/[a-z]+/'),
            tenants: new IterableAttr(
                new IntAttr(min: 1)
            )
        ),
    )]
    array $spooky
): void
{
    valid();
}
$value = [
    'id' => 10,
    'role' => [
        'mask' => 128,
        'name' => 'admin',
        'tenants' => [1, 2, 3, 4, 5]
    ],
];
myArray($value);

• Validate iterable int list:

use Chevere\Parameter\Attributes\IntAttr;
use Chevere\Parameter\Attributes\IterableAttr;
use function Chevere\Parameter\validate;

function myIterable(
    #[IterableAttr(
        new IntAttr(),
    )]
    array $list = [0,1,2]
): void
{
    valid();
}

Use function returnAttr() on the function/method body.

• Validate int [min: 0, max: 5] return:

use Chevere\Parameter\Attributes\IntAttr;
use Chevere\Parameter\Attributes\ReturnAttr;
use function Chevere\Parameter\returnAttr;

#[ReturnAttr(
    new IntAttr(min: 0, max: 5)
)]
public function myReturnInt(): int
{
    $result = 1;

    return returnAttr()($result);
}

• Validate array return:

use Chevere\Parameter\Attributes\ArrayAttr;
use Chevere\Parameter\Attributes\IntAttr;
use Chevere\Parameter\Attributes\StringAttr;
use Chevere\Parameter\Attributes\ReturnAttr;
use function Chevere\Parameter\returnAttr;

#[ReturnAttr(
    new ArrayAttr(
        id: new IntAttr(min: 0),
        name: new StringAttr()
    )
)]
public function myReturnArray(): array
{
    $result = [
        'id' => 1,
        'name' => 'Peoples Hernandez'
    ];

    return returnAttr()($result);
}

💡 By convention when omitting ReturnAttr the method public static function return(): ParameterInterface (if any) will be used to determine return validation rules.