[FlickrBridge] Fixed broken bridge

Following changes in the JSON data and selecting images for the
content (320x240 or bigger) and enclosure (largest version). All of
the data is now extracted from the JSON data instead of parsing the
DOM.

References #754

bridges/FlickrBridge.php

@@ -30,30 +30,76 @@ class FlickrBridge extends BridgeAbstract {
 				'title' => 'Insert username (as shown in the address bar)',
 				'exampleValue' => 'flickr'
 			)
-		),
+		)
 	);
 
 	public function collectData(){
+
 		switch($this->queriedContext) {
+
 		case 'Explore':
-			$key = 'photos';
+			$filter = 'photo-lite-models';
 			$html = getSimpleHTMLDOM(self::URI . 'explore')
 				or returnServerError('Could not request Flickr.');
 			break;
+
 		case 'By keyword':
-			$key = 'photos';
+			$filter = 'photo-lite-models';
 			$html = getSimpleHTMLDOM(self::URI . 'search/?q=' . urlencode($this->getInput('q')) . '&s=rec')
 				or returnServerError('No results for this query.');
 			break;
+
 		case 'By username':
-			$key = 'photoPageList';
+			$filter = 'photo-models';
 			$html = getSimpleHTMLDOM(self::URI . 'photos/' . urlencode($this->getInput('u')))
 				or returnServerError('Requested username can\'t be found.');
 			break;
+
 		default:
 			returnClientError('Invalid context: ' . $this->queriedContext);
+
 		}
 
+		$model_json = $this->extractJsonModel($html);
+		$photo_models = $this->getPhotoModels($model_json, $filter);
+
+		foreach($photo_models as $model) {
+
+			$item = array();
+
+			/* Author name depends on scope. On a keyword search the
+			* author is part of the picture data. On a username search
+			* the author is part of the owner data.
+			*/
+			if(array_key_exists('username', $model)) {
+				$item['author'] = $model['username'];
+			} elseif (array_key_exists('owner', reset($model_json)[0])) {
+				$item['author'] = reset($model_json)[0]['owner']['username'];
+			}
+
+			$item['title'] = (array_key_exists('title', $model) ? $model['title'] : 'Untitled');
+			$item['uri'] = self::URI . 'photo.gne?id=' . $model['id'];
+
+			$description = (array_key_exists('description', $model) ? $model['description'] : '');
+
+			$item['content'] = '<a href="'
+			. $item['uri']
+			. '"><img src="'
+			. $this->extractContentImage($model)
+			. '" style="max-width: 640px; max-height: 480px;"/></a><br><p>'
+			. $description
+			. '</p>';
+
+			$item['enclosures'] = $this->extractEnclosures($model);
+
+			$this->items[] = $item;
+
+		}
+
+	}
+
+	private function extractJsonModel($html) {
+
 		// Find SCRIPT containing JSON data
 		$model = $html->find('.modelExport', 0);
 		$model_text = $model->innertext;
@@ -62,59 +108,68 @@ class FlickrBridge extends BridgeAbstract {
 		$start = strpos($model_text, 'modelExport:') + strlen('modelExport:');
 		$end = strpos($model_text, 'auth:') - strlen('auth:');
 
-		// Dissect JSON data and remove trailing comma
+		// Extract JSON data, remove trailing comma
 		$model_text = trim(substr($model_text, $start, $end - $start));
 		$model_text = substr($model_text, 0, strlen($model_text) - 1);
 
-		$model_json = json_decode($model_text, true);
+		return json_decode($model_text, true);
 
-		foreach($html->find('.photo-list-photo-view') as $element) {
-			// Get the styles
-			$style = explode(';', $element->style);
-
-			// Get the background-image style
-			$backgroundImage = explode(':', end($style));
-
-			// URI type : url(//cX.staticflickr.com/X/XXXXX/XXXXXXXXX.jpg)
-			$imageURI = trim(str_replace(['url(', ')'], '', end($backgroundImage)));
-
-			// Get the image ID
-			$imageURIs = explode('_', basename($imageURI));
-			$imageID = reset($imageURIs);
-
-			// Use JSON data to build items
-			foreach(reset($model_json)[0][$key]['_data'] as $element) {
-				if($element['id'] === $imageID) {
-					$item = array();
-
-					/* Author name depends on scope. On a keyword search the
-					 * author is part of the picture data. On a username search
-					 * the author is part of the owner data.
-					 */
-					if(array_key_exists('username', $element)) {
-						$item['author'] = $element['username'];
-					} elseif (array_key_exists('owner', reset($model_json)[0])) {
-						$item['author'] = reset($model_json)[0]['owner']['username'];
 	}
 
-					$item['title'] = (array_key_exists('title', $element) ? $element['title'] : 'Untitled');
+	private function getPhotoModels($json, $filter) {
-					$item['uri'] = self::URI . 'photo.gne?id=' . $imageID;
 
-					$description = (array_key_exists('description', $element) ? $element['description'] : '');
+		// The JSON model contains a "legend" array, where each element contains
+		// the path to an element in the "main" object
+		$photo_models = array();
 
-					$item['content'] = '<a href="'
+		foreach($json['legend'] as $legend) {
-					. $item['uri']
-					. '"><img src="'
-					. $imageURI
-					. '" /></a><br><p>'
-					. $description
-					. '</p>';
 
-					$this->items[] = $item;
+			$photo_model = $json['main'];
 
-					break;
+			foreach($legend as $element) { // Traverse tree
+				$photo_model = $photo_model[$element];
 			}
+
+			// We are only interested in content
+			if($photo_model['_flickrModelRegistry'] === $filter) {
+				$photo_models[] = $photo_model;
 			}
+
 		}
+
+		return $photo_models;
+
 	}
+
+	private function extractEnclosures($model) {
+
+		$areas = array();
+
+		foreach($model['sizes'] as $size) {
+			$areas[$size['width'] * $size['height']] = $size['url'];
+		}
+
+		return array(max($areas));
+
+	}
+
+	private function extractContentImage($model) {
+
+		$areas = array();
+		$limit = 320 * 240;
+
+		foreach($model['sizes'] as $size) {
+
+			$image_area = $size['width'] * $size['height'];
+
+			if($image_area >= $limit) {
+				$areas[$image_area] = $size['url'];
+			}
+
+		}
+
+		return min($areas);
+
+	}
+
 }