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<?php |
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namespace Scriptotek\GoogleBooks; |
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use GuzzleHttp\Client; |
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class GoogleBooks |
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{ |
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/** |
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* @var string |
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*/ |
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protected $baseUri = 'https://www.googleapis.com/books/v1/'; |
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/** |
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* @var integer (Number of results to retrieve per batch, between 1 and 40) |
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*/ |
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protected $batchSize = 40; |
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/** |
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* @var Client |
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*/ |
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protected $http; |
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/** |
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* @var key string API key |
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*/ |
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protected $key; |
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/** |
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* @var country string 2 letter ISO 639 country code. |
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* |
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* The Books API must honor copyright laws from various countries, and have |
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* country-specific rights from publishers. It uses the IP address of the |
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* client to geo-locate the user, but if this fails for some reason, it will |
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* return 403 Forbidden with reason "unknownLocation". To avoid this, we can |
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* manually set the country code. |
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*/ |
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protected $country; |
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/** |
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* @var Volumes |
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*/ |
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public $volumes; |
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/** |
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* @var Bookshelves |
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*/ |
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public $bookshelves; |
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public function __construct($options = []) |
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{ |
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$this->http = new Client([ |
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'base_uri' => $this->baseUri, |
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'handler' => isset($options['handler']) ? $options['handler'] : null, |
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]); |
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$this->key = isset($options['key']) ? $options['key'] : null; |
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$this->country = isset($options['country']) ? $options['country'] : null; |
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$this->volumes = new Volumes($this); |
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$this->bookshelves = new Bookshelves($this); |
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$this->batchSize = isset($options['batchSize']) ? $options['batchSize'] : 40; |
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} |
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protected function raw($endpoint, $params = [], $method='GET') |
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{ |
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if (!is_null($this->key)) { |
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$params['key'] = $this->key; |
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} |
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if (!is_null($this->country)) { |
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$params['country'] = $this->country; |
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} |
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try { |
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$response = $this->http->request($method, $endpoint, [ |
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'query' => $params, |
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]); |
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} catch (\GuzzleHttp\Exception\ClientException $e) { |
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// 400 level errors |
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if ($e->getResponse()->getStatusCode() == 403) { |
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$json = json_decode($e->getResponse()->getBody()); |
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$domain = $json->error->errors[0]->domain; |
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$reason = $json->error->errors[0]->reason; |
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$message = $json->error->errors[0]->message; |
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if ($domain == 'usageLimits') { |
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throw new Exceptions\UsageLimitExceeded($message, $reason); |
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} |
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} |
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throw $e; |
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} catch (\GuzzleHttp\Exception\RequestException $e) { |
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// networking error (connection timeout, DNS errors, etc.) |
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// TODO: sleep and retry |
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throw $e; |
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} |
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return json_decode($response->getBody()); |
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} |
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public function getItem($path) |
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{ |
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return $this->raw($path); |
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} |
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public function listItems($endpoint, $params = []) |
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{ |
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$params['maxResults'] = $this->batchSize; |
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$i = 0; |
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while (true) { |
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$n = $i % $this->batchSize; |
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if ($n == 0) { |
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$params['startIndex'] = $i; |
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$response = $this->raw($endpoint, $params); |
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} |
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if (isset($response->totalItems) && $i >= $response->totalItems) { |
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return; |
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} |
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if (!isset($response->items[$n])) { |
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return; |
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} |
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yield $response->items[$n]; |
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$i++; |
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} |
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} |
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} |
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If you define a variable conditionally, it can happen that it is not defined for all execution paths.
Let’s take a look at an example:
In the above example, the variable $x is defined if you pass “foo” or “bar” as argument for $a. However, since the switch statement has no default case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
Define a default value for the variable:
Add a value for the missing path: