jsv4-php is a data validator, using version 4 JSON Schemas.

Just include jsv4.php from your code, and use the static methods on the Jsv4 class it defines.

Usage:

This usage returns an object of the following shape.

{
    "valid": true/false,
    "errors": [
        {...}
    ]
}

The values in the errors array are similar to those for tv4 (a similar project):

{
    "code": 0,
    "message": "Invalid type: string",
    "dataPath": "/intKey",
    "schemaKey": "/properties/intKey/type"
}

The code property corresponds to a constant corresponding to the nature of the validation error, e.g. JSV4_INVALID_TYPE. The names of these constants (and their values) match up exactly with the constants from tv4.

If you just want to know the validation status, and don't care what the errors actually are, then this is a more concise way of getting it.

It returns a boolean indicating whether the data correctly followed the schema.

Sometimes, the data is not quite the correct shape - but it could be made the correct shape by simple modifications.

If you call Jsv4::coerce($data, $schema), then it will attempt to change the data.

If it is successful, then a modified version of the data can be found in $result->value.

It's not psychic - in fact, it's quite limited. What it currently does is:

Perhaps you are using data from $_GET, so everything's a string, but the schema says certain values should be integers or booleans.

Jsv4::coerce() will attempt to convert strings to numbers/booleans only where the schema says, leaving other numerically-value strings as strings.

Perhaps the API needs a complete object (described using "required" in the schema), but only a partial one was supplied.

Jsv4::coerce() will attempt to insert appropriate values for the missing properties, using a default (if it is defined in a nearby "properties" entry) or by creating a value if it knows the type.

This class represents a collection of schemas. You include it from schema-store.php, and use it like this:

$store = new SchemaStore();
$store->add($url, $schema);
$retrieved = $store->get($url);

It can handle:

• Fragments in URLs, using both JSON Pointer fragments and identification using "id"
• Converts URIs in "id" and "$ref" to absolute (where possible)
• Resolves "$ref"s, splicing the resulting value into the schema
• Converts associative PHP arrays to objects - you can express your schema natively, but what you retrieve from the store is always an object.
• Adds sub-schemas according to their "id" - by default, this only happens if "id" is a sub-path of the current schema URL.

If the schemas being added are "trusted", then an extra argument can be supplied: $store->add($url, $schema, TRUE). In that case, the value of "id" is always believed for all sub-schemas.

A list of "missing" schemas (unresolved "$ref"s) can be retrieved used $store->missing().

This class does not depend on jsv4.php at all - it just deals with raw schema objects. As such, it could (hopefully) be used with other validators with minimal fuss.

The tests can be run using test.php (from the command-line or via the web).

This code is released under a do-anything-you-like "public domain" license (see LICENSE.txt).

It is also released under an MIT-style license (see LICENSE-MIT.txt) because there is sometimes benefit in having a recognised open-source license.