Scriptotek\OaiPmh\Records

Complexity

Total Complexity

23

Size/Duplication

Total Lines	196
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	5

Importance

Changes	1
Bugs	0	Features	0

10 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	15	1
A	__get()	0	6	2
A	getResumptionToken()	0	4	1
A	getLastResponse()	0	4	1
C	fetchMore()	0	49	8
A	current()	0	4	1
A	key()	0	4	1
A	rewind()	0	9	2
B	next()	0	15	5
A	valid()	0	4	1

<?php namespace Scriptotek\OaiPmh;

use Evenement\EventEmitter;

/**
 * When iterating, methods are called in the following order:
 * 
 * rewind()
 * valid()
 * current()
 *
 * next()
 * valid()
 * current()
 *
 * ...
 *
 * next()
 * valid()
 */
class Records extends EventEmitter implements \Iterator
{

    // When we no longer need to support PHP 5.3:
    // - Upgrade to Evenement 2.0 and use trait instead of extending

    private $from;
    private $until;
    private $set;
    private $client;
    private $lastResponse;

    private $position;
    private $initialPosition;
    private $resumptionToken;
    private $initialResumptionToken;

    /** @var int Total number of records in the result set. Only defined if the
        server returns 'completeListSize', which is optional. Even if defined, the
        value may still be only an estimate. */
    public $numberOfRecords = null;

    private $data = array();

    /**
     * Create a new records iterator
     *
     * @param string $from Start date
     * @param string $until End date
     * @param string $set Data set
     * @param Client $client OAI-PMH client reference
     * @param string $resumptionToken
     */
    public function __construct($from, $until, $set, Client $client, $resumptionToken = null)
    {
        $this->from = $from;
        $this->until = $until;
        $this->set = $set;
        $this->client = $client;
        $this->resumptionToken = $resumptionToken;

        $this->position = 1;
        $this->fetchMore();

        // Store initial position, might not be 1 if we are resuming an operation
        $this->initialPosition = $this->position;
        $this->initialResumptionToken = $resumptionToken;
    }

    /**
     * Return error message from last reponse, if any
     *
     * @return string|null
     */
    public function __get($prop)
    {
        if (in_array($prop, array('error', 'errorCode'))) {
            return $this->lastResponse->{$prop};
        }
    }

    /**
     * Return the current resumption token
     *
     * @return string|null
     */
    public function getResumptionToken()
    {
        return $this->resumptionToken;
    }

    /**
     * Return the last response object
     *
     * @return ListRecordsResponse|null
     */
    public function getLastResponse()
    {
        return $this->lastResponse;
    }

    /**
     * Fetch more records from the service
     */
    private function fetchMore()
    {
        if (is_null($this->resumptionToken)) {
            $args = array(
                'from' => $this->from,
                'until' => $this->until,
                'set' => $this->set,
            );
        } else {
            $args = array(
                'resumptionToken' => $this->resumptionToken,
                'metadataPrefix' => null,
            );
        }

        $attempt = 0;
        while (true) {
            $body = $this->client->request('ListRecords', $args);
            try {
                $this->lastResponse = new ListRecordsResponse($body);
                break;
            } catch (\Danmichaelo\QuiteSimpleXMLElement\InvalidXMLException $e) {
                $this->emit('request.error', array(
                    'message' => $e->getMessage(),
                ));
                $attempt++;
                if ($attempt > $this->client->maxRetries) {
                    // Give up
                    throw new ConnectionError('Failed to get a valid XML response from the server.', null, $e);
                }
                time_nanosleep(intval($this->client->sleepTimeOnError), intval($this->client->sleepTimeOnError * 1000000000));
            }
        }

        $this->data = $this->lastResponse->records;

        if (!is_null($this->lastResponse->numberOfRecords)) {
            $this->numberOfRecords = $this->lastResponse->numberOfRecords;
            if (!is_null($this->lastResponse->cursor)) {
                $this->position = $this->lastResponse->cursor + 1;
            }
        }

        if (isset($this->lastResponse->resumptionToken)) {
            $this->resumptionToken = $this->lastResponse->resumptionToken;
        } else {
            $this->resumptionToken = null;
        }
    }

    /**
     * Return the current element
     *
     * @return mixed
     */
    public function current()
    {
        return $this->data[0];
    }

    /**
     * Return the key of the current element
     *
     * @return int
     */
    public function key()
    {
        return $this->position;
    }

    /**
     * Rewind the Iterator to the first element
     */
    public function rewind()
    {
        if ($this->position != $this->initialPosition) {
            $this->position = $this->initialPosition;
            $this->resumptionToken = $this->initialResumptionToken;
            $this->data = array();
            $this->fetchMore();
        }
    }

    /**
     * Move forward to next element
     */
    public function next()
    {
        if (count($this->data) > 0) {
            array_shift($this->data);
        }
        ++$this->position;

        if (count($this->data) == 0 && !is_null($this->resumptionToken)) {
            $this->fetchMore();
        }

        if (count($this->data) == 0) {
            return null;
        }
    }

    /**
     * Check if current position is valid
     *
     * @return bool
     */
    public function valid()
    {
        return count($this->data) != 0;
    }
}