JSON Schema ASG builder for PHP

Author: Joost Nijhuis <[email protected]>

A PHP Implementation for building an ASG (Abstract semantic graph) from a reference to a JSON schema file.
Support for json schemas defined in JSON and YAML.
Full support for the JSON schema draft 07 specification. More information can be found here.
The ASG is visitable and can be visited by implementing a visitor (Behavioral Design Pattern Visitor).

Purposes of this library are:

• Validate JSON Schemas and give the end user a precise error message about semantically errors
• Transform an ASG into something else. For example generate entity classes from it, generate static validation classes, etc...
• Travers ASG by implementing your own visitor. (implement Jojo1981\JsonSchemaAsg\Visitor\VisitorInterface)

JSON Schema is a vocabulary that allows you to annotate and validate JSON documents. More information can be found here.

Installation

Library

git clone https://github.com/jojo1981/json-schema-asg.git

Composer

Install PHP Composer

composer require jojo1981/json-schema-asg

Implement your own visitor.

Make sure when implementing the method: visitReferenceNode you check if the reference is circular. for example:

    /**
     * @param ReferenceNode $referenceNode
     * @return mixed
     */
    public function visitReferenceNode(ReferenceNode $referenceNode)
    {
        if (!$referenceNode->isCircular()) {
            $referenceNode->getPointToSchema()->accept($this);
        }
    }

Usage

Make sure the reference is an absolute reference to a url or file on the local file system.

<?php

require 'vendor/autoload.php';

$schemaResolverFactory = new Jojo1981\JsonSchemaAsg\SchemaResolverFactory();
$schemaResolver = $schemaResolverFactory->getSchemaResolver();

// Example local files
$schemaFilenames = [
    'resources/schemas/address.schema.json',
    'resources/schemas/calendar.schema.json',
    'resources/schemas/card.schema.json',
    'resources/schemas/customer.schema.json',
    'resources/schemas/geographical-location.schema.json'
];

foreach ($schemaFilenames as $relativeSchemaFilename) {
    $absoluteSchemaFilename = \realpath($relativeSchemaFilename);
    $reference = new Jojo1981\JsonSchemaAsg\Value\Reference($absoluteSchemaFilename . '#/');
    $schema = $schemaResolver->resolveSchema($reference);
}

// Example urls
$schemaUrls = [
    'https://raw.githubusercontent.com/jojo1981/json-schema-asg/master/resources/schemas/address.schema.json',
    'https://raw.githubusercontent.com/jojo1981/json-schema-asg/master/resources/schemas/calendar.schema.json',
    'https://raw.githubusercontent.com/jojo1981/json-schema-asg/master/resources/schemas/card.schema.json',
    'https://raw.githubusercontent.com/jojo1981/json-schema-asg/master/resources/schemas/customer.schema.json',
    'https://raw.githubusercontent.com/jojo1981/json-schema-asg/master/resources/schemas/geographical-location.schema.json'
];

foreach ($schemaUrls as $schemaUrl) {
    $reference = new Jojo1981\JsonSchemaAsg\Value\Reference($schemaUrl . '#/');
    $schema = $schemaResolver->resolveSchema($reference);
}