A simple package to verify a set of array values, which are most likely parameters in a call. Sometimes you cannot specify in a list of arguments perhaps because it's too long, or because they might vary too much between derived class types.

This class is configured with an array which provides what values are required and their types. Non-required values can also be included to be checked - in which case they are only checked if they are present.

The main function returns an array of errors. If it's empty then everything was fine.

Structure

The settings array looks like this:

[
  'name' => [
    'required' => true,
    'type' => 'string',
    'data' => '',
    'range' => []
  ]
]

The 'name' is the key value in the array being tested (the name of the property).

Only the 'type' key is mandatory, and must be one of the acceptable values; the 'required' key is assumed false if missing; some types require an additional data string, for a 'regex' type it's the regular expression, for the 'class' type it's the fully qualified class name, and so on.

The 'range' key applies to string, int and float, and allows length and range restrictions to be inserted.

If a named parameter is in the settings array but not "required", no error is generated if it's missing, but it will be tested if it is present.

Types

The complete list of types:

any matches anything
null matches only a null value (for completeness, you never know)
class matches a specific class or interface (FQN in 'data')
object matches any object
array matches any array, arrays can contain their own definitions (see later).
int matches an integer value (and can have a range)
bool only matches true or false
int_bool matches true, false, 1 and 0
float matches a float value (and can have a range)
string matches any string (and can have a range)
string_list matches a string against a fixed list of strings (in 'data' separated by '|'). This is an old style "enum" which is also used to verify the types of the settings/configuration items.
regex tests a string with a regular expression (in 'data')
callable only matches a callable
resource only matches a resource
url matches a string which is also a valid URL
email matches a string which is also a valid email address
enum only matches a PHP8.1 enum (FQN in 'data')

How to use it

$settings = [
  'name' => [
    'required' => true,
    'type' => 'string'
  ],
  'value' => [
    'required' => true,
    'type' => 'int'
    'range' => [
      'min_value' => 1,
      'max_value' => 10
    ]
  ]
];

$paramVerifyFactory = new \ParamVerify\ParamVerifyFactory();

// This checks the settings and will throw an exception on error.
$verifier = $paramVerifyFactory->make($settings);

// Will return an error because 'name' is missing.
$parameters = ['value' => 5];
$errors = $verifier->verify($parameters);

// Will return no errors.
$parameters = ['name' => 'banana', 'value' => 5];
$errors = $verifier->verify($parameters);

// Will return an error because value is out of range.
$parameters = ['name' => 'banana', 'value' => 15];
$errors = $verifier->verify($parameters);

// Will return an error because name is not a string.
$parameters = ['name' => ['banana'], 'value' => 15];
$errors = $verifier->verify($parameters);

Array sub-properties

Arrays can have an additional property called settings which defines a set of sub-properties for the array. There is no limit on the nesting - apart from resources and whether it's really a good idea.

$settings = [
  'name' => [
    'required' => true,
    'type' => 'string'
  ],
  'address' => [
    'required' => true,
    'type' => 'array'
    'settings' => [
      'line1' => ['required' => true, 'type' => 'string'],
      'line2' => ['type' => 'string'],
      'line3' => ['type' => 'string'],
      'postal_code' => ['required' => true, 'type' => 'string'],
    ]
  ]
];

$paramVerifyFactory = new \ParamVerify\ParamVerifyFactory();

// This checks the settings and will throw an exception on error.
$verifier = $paramVerifyFactory->make($settings);

// This would not generate any errors.
$parameters = [
  'name' => 'jane',
  'address' => [
    'line1' => 'first line of address',
    'line3' => 'third line of address',
    'postal_code' => 'XX1 73YY'
  ]
];
$errors = $verifier->verify($parameters);