GetThumbnails

<?php

// This class receives a page URL from the user then searches
// the destination for potential thumbnails via Embedly.
// The thumbnails (if found) are then returned as base64 in a JSON response.
class GetThumbnails{

    private $embedlyPrivateKey = '<HIDDEN - YOU CAN GET ONE FOR FREE FROM EMBED.LY>';

    private $initialPageUrl;

    // Misc info about code execution for debugging purposes.
    private $debugInfoArray = array();

    private $imageFlavour; // jpeg | x-icon
    private $imagesToKeep;
    private $maxWidth;
    private $maxHeight;

    public function __construct(){

        $this->imagesToKeep = 3;
        $this->maxWidth = 70;
        $this->maxHeight = 55;

        // *No security for now! (regex later).
        if(isset($_GET['pageUrl']) && $_GET['pageUrl'] != ''){
            $this->initialPageUrl = $_GET['pageUrl'];
        }else{
            // STATIC URL FOR DEMO ONLY - replace for different results.
            $this->initialPageUrl = 'http://www.microsoft.com';
        }

        $imageUrlArray = $this->getImagesByPageUrl($this->initialPageUrl);

        $thumbnailedImages = $this->thumbnailImagesViaEmbedly($imageUrlArray['imageUrlArray']);

        // FOLLOWING OUTPUT IS FOR DEMO ONLY
            echo '<pre>';

                echo '<u>The JSON array returned to the user:</u><br><br>';

                print_r(array(
                    'debugInfoArray'=>$this->debugInfoArray,
                    'finalPageUrl'=>$imageUrlArray['finalPageUrl'],
                    'imageUrlArray'=>$imageUrlArray['imageUrlArray'],
                    'thumbnailedImages'=>$thumbnailedImages,
                    'thumbnailDimensions'=>array(
                        'width'=>$this->maxWidth,
                        'height'=>$this->maxHeight
                    )
                ));

                echo '<br><u>Sample images:</u><br>';

                if(count($imageUrlArray['imageUrlArray']) == 0){
                    echo '<br>No images found.';
                }else{
                    for($i=0; $i<count($imageUrlArray['imageUrlArray']); $i++){
                        echo '<br>Image ' . ($i+1) . ' before being cropped and thumbed:<br><br>';
                        echo '<img src="' . $imageUrlArray['imageUrlArray'][$i] . '" /><br>';
                        echo '<br>Image ' . ($i+1) . ' after being cropped and thumbed:<br><br>';
                        echo '<img src="' . $thumbnailedImages[$i] . '" /><br>';
                    }
                }

            echo '</pre>';
        // END DEMO ONLY

        // Return all data to user via JSON.
        // echo json_encode(array(
            // 'debugInfoArray'=>$this->debugInfoArray,
            // 'finalPageUrl'=>$imageUrlArray['finalPageUrl'],
            // 'imageUrlArray'=>$imageUrlArray['imageUrlArray'],
            // 'thumbnailedImages'=>$thumbnailedImages,
            // 'thumbnailDimensions'=>array(
                // 'width'=>$this->maxWidth,
                // 'height'=>$this->maxHeight
            // )
        // ));
    }

    // This function accepts a page URL.
    // Embedly uses this URL to find images on that page. (see: http://embed.ly/docs/api/extract)
    // Returns array of found image URLs.
    private function getImagesByPageUrl($pageURL){

        $imageUrlArray = array();

        // Follow any redirects from original URL before requesting images.
        $finalPageUrl = $this->cURL($pageURL)['finalPageUrl'];

        $curlResponse = $this->cURL('http://api.embed.ly/1/extract?key='.$this->embedlyPrivateKey.'&url='.urlencode($finalPageUrl));
        $responseCode = $curlResponse['responseCode'];
        $embedlyJSON = json_decode($curlResponse['embedlyJSON'], true);

        if($responseCode == '200'){

            if(!empty($embedlyJSON['images'])){

                $this->imageFlavour = 'jpeg';

                $this->debugInfo("Embedly found ".count($embedlyJSON['images'])." images.");

                if(count($embedlyJSON['images']) >= $this->imagesToKeep){
                    $this->debugInfo("Keeping first ".$this->imagesToKeep."..");
                }

                foreach($embedlyJSON['images'] as $embedlyImageURL){
                    array_push($imageUrlArray, $embedlyImageURL['url']);
                }

            }else{

                $this->debugInfo("Embedly failed to find images.");
                $this->debugInfo("Searching for favicon..");

                if(!empty($embedlyJSON['favicon_url'])){

                    $this->imageFlavour = 'x-icon';

                    $this->debugInfo("Embedly found a favicon.");

                    array_push($imageUrlArray, $embedlyJSON['favicon_url']);

                }else{
                    $this->debugInfo("Embedly failed to find favicon..");
                    $this->debugInfo("Default thumbnail will be used..");
                }
            }

            if(count($imageUrlArray) > $this->imagesToKeep){
                $imageUrlArray = array_slice($imageUrlArray, 0, $this->imagesToKeep, true);
            }

        }else{
            $this->debugInfo("Page response was \"" . $responseCode . "\"..");
        }

        return array(
            'responseCode'=>$responseCode,
            'finalPageUrl'=>$finalPageUrl,
            'imageUrlArray'=>$imageUrlArray
        );
    }

    // This function creates thumbnails and returns them in base64.
    // Image URLs are sent to Embedly along with desired dimensions for cropping. (see: http://embed.ly/docs/api/display/endpoints/1/display/crop)
    // Responses are base64 encoded before being returned to user via JSON (Instead of using JavaScript which would reveal Embedly private key).
    private function thumbnailImagesViaEmbedly($imageUrlArray){

        $imageSourceBase64Array = array();

        if(!empty($imageUrlArray)){

            if($this->imageFlavour == 'jpeg'){

                foreach($imageUrlArray as $selectedimageSource){

                    $thumbnailedImageUrl = $this->cURL(
                        'https://i.embed.ly/1/display/crop?key='.
                        $this->embedlyPrivateKey.
                        '&url='.urlencode($selectedimageSource).
                        '&height='.$this->maxHeight.
                        '&width='.$this->maxWidth)['embedlyJSON'];

                    array_push($imageSourceBase64Array, 'data:image/'.$this->imageFlavour.';base64,'.base64_encode($thumbnailedImageUrl));
                }

            }elseif ($this->imageFlavour == 'x-icon'){

                // Thumbnails (x-icon) are not cropped, so no need to send back to Embedly first.

                array_push($imageSourceBase64Array, 'data:image/'.$this->imageFlavour.';base64,'.base64_encode($this->cURL($imageUrlArray[0])['embedlyJSON']));

                // Make sure favicon remains square.
                $this->maxWidth = $this->maxHeight;

            }
        }else{
            $this->debugInfo("No URLs provided for cropping - No images were cropped..");
        }

        return $imageSourceBase64Array;
    }

    // Function accepts URL as parameter.
    // Returns array of:
    //   JSON from Embedly.
    //   Response code. (200, 404 etc.).
    //   Redirect URL (if supplied URL is redirected).
    private function cURL($pageURL){

        $ch = curl_init($pageURL);

        curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.134 Safari/537.36');

        // Return page as string only.
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

        // Disabled to avoid some errors.
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

        // Follow all redirected URLs.
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);

        $embedlyJSON = curl_exec($ch);
        $responseCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $finalPageUrl = curl_getinfo($ch, CURLINFO_EFFECTIVE_URL);

        curl_close($ch);

        return array(
            'embedlyJSON'=>$embedlyJSON,
            'responseCode'=>$responseCode,
            'finalPageUrl'=>$finalPageUrl
        );
    }

    private function debugInfo($info){
        array_push($this->debugInfoArray, $info);
    }

    // END CLASS GetThumbnails()
}

$thumbnails = new GetThumbnails;

?>