<?php
/*
* This file is part of the JsonSchema package.
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace JsonSchema\Uri;
use JsonSchema\Exception\InvalidSchemaMediaTypeException;
use JsonSchema\Exception\JsonDecodingException;
use JsonSchema\Exception\ResourceNotFoundException;
use JsonSchema\Uri\Retrievers\FileGetContents;
use JsonSchema\Uri\Retrievers\UriRetrieverInterface;
use JsonSchema\UriRetrieverInterface as BaseUriRetrieverInterface;
use JsonSchema\Validator;
/**
* Retrieves JSON Schema URIs
*
* @author Tyler Akins <fidian@rumkin.com>
*/
class UriRetriever implements BaseUriRetrieverInterface
{
/**
* @var array Map of URL translations
*/
protected $translationMap = array(
// use local copies of the spec schemas
'|^https?://json-schema.org/draft-(0[34])/schema#?|' => 'package://dist/schema/json-schema-draft-$1.json'
);
/**
* @var array A list of endpoints for media type check exclusion
*/
protected $allowedInvalidContentTypeEndpoints = array(
'http://json-schema.org/',
'https://json-schema.org/'
);
/**
* @var null|UriRetrieverInterface
*/
protected $uriRetriever = null;
/**
* @var array|object[]
*
* @see loadSchema
*/
private $schemaCache = array();
/**
* Adds an endpoint to the media type validation exclusion list
*
* @param string $endpoint
*/
public function addInvalidContentTypeEndpoint($endpoint)
{
$this->allowedInvalidContentTypeEndpoints[] = $endpoint;
}
/**
* Guarantee the correct media type was encountered
*
* @param UriRetrieverInterface $uriRetriever
* @param string $uri
*
* @return bool|void
*/
public function confirmMediaType($uriRetriever, $uri)
{
$contentType = $uriRetriever->getContentType();
if (is_null($contentType)) {
// Well, we didn't get an invalid one
return;
}
if (in_array($contentType, array(Validator::SCHEMA_MEDIA_TYPE, 'application/json'))) {
return;
}
foreach ($this->allowedInvalidContentTypeEndpoints as $endpoint) {
if (strpos($uri, $endpoint) === 0) {
return true;
}
}
throw new InvalidSchemaMediaTypeException(sprintf('Media type %s expected', Validator::SCHEMA_MEDIA_TYPE));
}
/**
* Get a URI Retriever
*
* If none is specified, sets a default FileGetContents retriever and
* returns that object.
*
* @return UriRetrieverInterface
*/
public function getUriRetriever()
{
if (is_null($this->uriRetriever)) {
$this->setUriRetriever(new FileGetContents());
}
return $this->uriRetriever;
}
/**
* Resolve a schema based on pointer
*
* URIs can have a fragment at the end in the format of
* #/path/to/object and we are to look up the 'path' property of
* the first object then the 'to' and 'object' properties.
*
* @param object $jsonSchema JSON Schema contents
* @param string $uri JSON Schema URI
*
* @throws ResourceNotFoundException
*
* @return object JSON Schema after walking down the fragment pieces
*/
public function resolvePointer($jsonSchema, $uri)
{
$resolver = new UriResolver();
$parsed = $resolver->parse($uri);
if (empty($parsed['fragment'])) {
return $jsonSchema;
}
$path = explode('/', $parsed['fragment']);
while ($path) {
$pathElement = array_shift($path);
if (!empty($pathElement)) {
$pathElement = str_replace('~1', '/', $pathElement);
$pathElement = str_replace('~0', '~', $pathElement);
if (!empty($jsonSchema->$pathElement)) {
$jsonSchema = $jsonSchema->$pathElement;
} else {
throw new ResourceNotFoundException(
'Fragment "' . $parsed['fragment'] . '" not found'
. ' in ' . $uri
);
}
if (!is_object($jsonSchema)) {
throw new ResourceNotFoundException(
'Fragment part "' . $pathElement . '" is no object '
. ' in ' . $uri
);
}
}
}
return $jsonSchema;
}
/**
* {@inheritdoc}
*/
public function retrieve($uri, $baseUri = null, $translate = true)
{
$resolver = new UriResolver();
$resolvedUri = $fetchUri = $resolver->resolve($uri, $baseUri);
//fetch URL without #fragment
$arParts = $resolver->parse($resolvedUri);
if (isset($arParts['fragment'])) {
unset($arParts['fragment']);
$fetchUri = $resolver->generate($arParts);
}
// apply URI translations
if ($translate) {
$fetchUri = $this->translate($fetchUri);
}
$jsonSchema = $this->loadSchema($fetchUri);
// Use the JSON pointer if specified
$jsonSchema = $this->resolvePointer($jsonSchema, $resolvedUri);
if ($jsonSchema instanceof \stdClass) {
$jsonSchema->id = $resolvedUri;
}
return $jsonSchema;
}
/**
* Fetch a schema from the given URI, json-decode it and return it.
* Caches schema objects.
*
* @param string $fetchUri Absolute URI
*
* @return object JSON schema object
*/
protected function loadSchema($fetchUri)
{
if (isset($this->schemaCache[$fetchUri])) {
return $this->schemaCache[$fetchUri];
}
$uriRetriever = $this->getUriRetriever();
$contents = $this->uriRetriever->retrieve($fetchUri);
$this->confirmMediaType($uriRetriever, $fetchUri);
$jsonSchema = json_decode($contents);
if (JSON_ERROR_NONE < $error = json_last_error()) {
throw new JsonDecodingException($error);
}
$this->schemaCache[$fetchUri] = $jsonSchema;
return $jsonSchema;
}
/**
* Set the URI Retriever
*
* @param UriRetrieverInterface $uriRetriever
*
* @return $this for chaining
*/
public function setUriRetriever(UriRetrieverInterface $uriRetriever)
{
$this->uriRetriever = $uriRetriever;
return $this;
}
/**
* Parses a URI into five main components
*
* @param string $uri
*
* @return array
*/
public function parse($uri)
{
preg_match('|^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?|', $uri, $match);
$components = array();
if (5 < count($match)) {
$components = array(
'scheme' => $match[2],
'authority' => $match[4],
'path' => $match[5]
);
}
if (7 < count($match)) {
$components['query'] = $match[7];
}
if (9 < count($match)) {
$components['fragment'] = $match[9];
}
return $components;
}
/**
* Builds a URI based on n array with the main components
*
* @param array $components
*
* @return string
*/
public function generate(array $components)
{
$uri = $components['scheme'] . '://'
. $components['authority']
. $components['path'];
if (array_key_exists('query', $components)) {
$uri .= $components['query'];
}
if (array_key_exists('fragment', $components)) {
$uri .= $components['fragment'];
}
return $uri;
}
/**
* Resolves a URI
*
* @param string $uri Absolute or relative
* @param string $baseUri Optional base URI
*
* @return string
*/
public function resolve($uri, $baseUri = null)
{
$components = $this->parse($uri);
$path = $components['path'];
if ((array_key_exists('scheme', $components)) && ('http' === $components['scheme'])) {
return $uri;
}
$baseComponents = $this->parse($baseUri);
$basePath = $baseComponents['path'];
$baseComponents['path'] = UriResolver::combineRelativePathWithBasePath($path, $basePath);
return $this->generate($baseComponents);
}
/**
* @param string $uri
*
* @return bool
*/
public function isValid($uri)
{
$components = $this->parse($uri);
return !empty($components);
}
/**
* Set a URL translation rule
*/
public function setTranslation($from, $to)
{
$this->translationMap[$from] = $to;
}
/**
* Apply URI translation rules
*/
public function translate($uri)
{
foreach ($this->translationMap as $from => $to) {
$uri = preg_replace($from, $to, $uri);
}
// translate references to local files within the json-schema package
$uri = preg_replace('|^package://|', sprintf('file://%s/', realpath(__DIR__ . '/../../..')), $uri);
return $uri;
}
}