public function fromXml(\SimpleXMLElement $entryXml)
    {
        Validate::notNull($entryXml, 'entryXml');

        $this->attributes = (array) $entryXml->attributes();
        $entryArray = (array) $entryXml;

        if (array_key_exists(Resources::AUTHOR, $entryArray)) {
            $this->author = $this->processAuthorNode($entryArray);
        }

        if (array_key_exists(Resources::CATEGORY, $entryArray)) {
            $this->category = $this->processCategoryNode($entryArray);
        }

        if (array_key_exists('content', $entryArray)) {
            $content = new Content();
            $content->fromXml($entryArray['content']);
            $this->content = $content;
        }

        if (array_key_exists(Resources::CONTRIBUTOR, $entryArray)) {
            $this->contributor = $this->processContributorNode($entryArray);
        }

        if (array_key_exists('id', $entryArray)) {
            $this->id = (string) $entryArray['id'];
        }

        if (array_key_exists(Resources::LINK, $entryArray)) {
            $this->link = $this->processLinkNode($entryArray);
        }

        if (array_key_exists('published', $entryArray)) {
            $this->published = $entryArray['published'];
        }

        if (array_key_exists('rights', $entryArray)) {
            $this->rights = $entryArray['rights'];
        }

        if (array_key_exists('source', $entryArray)) {
            $source = new Source();
            $source->parseXml($entryArray['source']->asXML());
            $this->source = $source;
        }

        if (array_key_exists('title', $entryArray)) {
            $this->title = $entryArray['title'];
        }

        if (array_key_exists('updated', $entryArray)) {
            $this->updated = \DateTime::createFromFormat(
                \DateTime::ATOM,
                (string) $entryArray['updated']
            );
        }
    }