JSONSchema

JSONSchema is a simple schema validator for JSON formats.

JSONSchema requires PHP 5.3+.

Installation

JSONSchema uses Composer to manage its description and dependencies (which, currently, are none). You can install Composer system-wide or just add composer.phar to the root of this project after cloning. Afterwards, you simply call php composer.phar install in the project root to install the necessary dependencies.

JSONSchema is not up at Packagist at the moment, but you can easily specify JSONSchema as a dependency in your own composer.json by adding the project's GitHub repository to your own composer.json.

{
    // ...
    "repositories": [
    {
      "type": "vcs",
      "url": "git://github.com/maikg/JSONSchema.git"
    }
    ],
    "require": {
      "maikg/jsonschema": "*"
    }
    // ...
}

Usage

<?PHP
use JSON\Schema;

$json = ...; // JSON string, array or object instance.

// Note that you specify the type of the root object, which should be an object
// or an array.
$schema = new Schema(Schema::TYPE_OBJECT, function($obj) {
    $obj->includes('name', Schema::TYPE_OBJECT, function($obj) {
        $obj->includes('first', Schema::TYPE_STRING);
        $obj->includes('last', Schema::TYPE_STRING);
    });.
    $obj->excludes('full_name');
    $obj->optional('date_of_birth', Schema::TYPE_STRING, function($dob) {
        return preg_match('/^\d{4}-\d{2}-\d{2}$/', $dob);
    });
    $obj->includes('nicknames', Schema::TYPE_ARRAY, function($arr) {
        $arr->all(Schema::TYPE_STRING, function($nickname) {
            return (strlen($nickname) > 0);
        });
    });
});

if (!$schema->validate($json)) {
    var_dump($schema->getValidationErrors());
}


$schema = new Schema(Schema::TYPE_OBJECT, function($obj) {
    // It's also possible to specify multiple types for a single key.
    // 
    // This example requires the 'name' key to be present, but it can be either NULL or a string.
    // When specifying a custom validation when using this syntax, it is called always
    // whenever the actual type matches one of the expected types, except when the actual
    // type is NULL.
    // 
    // This currently only works for "flat" types: string, number, boolean and NULL.
    $obj->includes('name', Schema::TYPE_STRING | Schema::TYPE_NULL, function($str) {
        // Only called when $root['name'] is a string.
    });
    
    // By default, other keys that are not explicitly defined are not allowed and a
    // ValidationError will be added containing a message specifying which keys were
    // unexpected. You can override this behavior.
    $obj->allowsOtherKeys(true);
});
?>

TODO

• Make certain logical operations possible, such as "either include first_name and last_name OR include full_name".
• Allow regular expressions for the string type to be specified directly, without wrapping them up in a function.
• Add more validation methods for the array type:
  • Specify the expected amount of items in the array (either exact or through a minimum and/or maximum).
  • Specify the expected type/value at a certain index.
• Better error messages.
• Extend multiple type support to aggregate types as well.