/**
* Helper method to include lazysizes. Prevent multiple inclusions.
*/
static function requireLazySizes()
{
if (self::$_alreadyIncluded) {
return false;
}
$basePath = LazySizesImageExtension::config()->js_path;
Requirements::customScript(<<<JS
window.lazySizesConfig = {
addClasses: true
};
JS
);
Requirements::javascript($basePath . '/lazysizes.min.js');
self::$_alreadyIncluded = true;
}
/**
* Requires the necessary JS and sends the required HTML structure to the template
* for a responsive image set
*
* @param array $config The configuration of the responsive image set from the config
* @param array $args The arguments passed to the responsive image method, e.g. $MyImage.ResponsiveSet1(800x600)
* @param string $method The method, or responsive image set, to generate
* @return SSViewer
*/
protected function createResponsiveSet($config, $args, $method)
{
LazySizesControllerExtension::requireLazySizes();
if (!isset($config['sizes']) || !is_array($config['sizes'])) {
throw new Exception("Responsive set {$method} does not have sizes defined in its config.");
}
// Resolve size
if (isset($args[0])) {
$defaultDimensions = $args[0];
} elseif (isset($config['default_size'])) {
$defaultDimensions = $config['default_size'];
} else {
$defaultDimensions = self::config()->default_size;
}
// Resolve method name
if (isset($args[1])) {
$methodName = $args[1];
} elseif (isset($config['method'])) {
$methodName = $config['method'];
} else {
$methodName = self::config()->default_method;
}
$srcset = $this->owner->srcset($config['sizes'], false, $methodName);
list($default_width, $default_height) = $this->parseDimensions($defaultDimensions);
// Render template
$template = 'LazySizesImage';
// If we have a srcset, use a template according to pattern
if (!empty($srcset)) {
$template .= ucfirst(self::config()->pattern);
}
// When using lqip, render a low res image
$srclqip = '';
if (self::config()->pattern == 'lqip') {
$lqip = self::config()->lqip_multiplier;
$srclqip = $this->owner->getFormattedImage($methodName, $default_width * $lqip, $default_height * $lqip)->Link();
}
return $this->owner->customise(array('ImageSrcSet' => $srcset, 'SrcLqip' => $srclqip, 'DefaultImage' => $this->owner->getFormattedImage($methodName, $default_width, $default_height)))->renderWith($template);
}
