Exporting to JSON Schema

Export

JsonSchema::export() turns your schema into a JSON Schema document, the format editors read to offer completion and underline mistakes directly in the JSON or YAML file:

use Nette\Schema\Expect;
use Nette\Schema\JsonSchema;

$schema = Expect::structure([
	'host' => Expect::string('localhost')->description('Database server hostname'),
	'port' => Expect::int(3306)->min(1)->max(65535),
	'user' => Expect::string()->required(),
]);

echo json_encode(JsonSchema::export($schema), JSON_PRETTY_PRINT);

{
	"type": "object",
	"properties": {
		"host": {"type": "string", "description": "Database server hostname"},
		"port": {"type": "integer", "minimum": 1, "maximum": 65535},
		"user": {"type": "string"}
	},
	"required": ["user"],
	"additionalProperties": false
}

Save the result into a file and point your editor to it; how exactly depends on the editor and the format of the configuration file.

What the Export Contains

The export describes the shape of the data: types, ranges, patterns, required items, enum values and the texts you added with description().

Default values, castTo() and transform() are deliberately left out, because they describe what happens to the data after validation, and JSON Schema has no way to say that.

A type that exists only in PHP, such as a class (Expect::type(Address::class)), a callable or a resource, cannot be exported at all. Instead of producing a document that would quietly describe something else, the export throws Nette\NotSupportedException. The same goes for a custom element, whose rules the export cannot know.

Differences from Validation

Two differences remain between the export and the validation. JSON Schema counts the length of a string in characters, while Expect::string() counts bytes, so use Expect::unicode() for text that is not plain ASCII. And a pattern() is exported as it is, but a JSON Schema validator reads it as an ECMAScript regular expression, so constructions specific to PCRE may be understood differently there.