Pimcore\Model\Asset\Image\Thumbnail::getHTML PHP Method

    public function getHTML($options = [], $removeAttributes = [])
    {
        $image = $this->getAsset();
        $attributes = [];
        $pictureAttribs = [];
        // this is used for the html5 <picture> element
        // re-add support for disableWidthHeightAttributes
        if (isset($options['disableWidthHeightAttributes']) && $options['disableWidthHeightAttributes']) {
            // make sure the attributes are removed
            $removeAttributes = array_merge($removeAttributes, ['width', 'height']);
        } else {
            if ($this->getWidth()) {
                $attributes['width'] = 'width="' . $this->getWidth() . '"';
            }
            if ($this->getHeight()) {
                $attributes['height'] = 'height="' . $this->getHeight() . '"';
            }
        }
        $w3cImgAttributes = ["alt", "align", "border", "height", "hspace", "ismap", "longdesc", "usemap", "vspace", "width", "class", "dir", "id", "lang", "style", "title", "xml:lang", "onmouseover", "onabort", "onclick", "ondblclick", "onmousedown", "onmousemove", "onmouseout", "onmouseup", "onkeydown", "onkeypress", "onkeyup", "itemprop", "itemscope", "itemtype"];
        $customAttributes = [];
        if (array_key_exists("attributes", $options) && is_array($options["attributes"])) {
            $customAttributes = $options["attributes"];
        }
        $altText = "";
        $titleText = "";
        if (isset($options["alt"])) {
            $altText = $options["alt"];
        }
        if (isset($options["title"])) {
            $titleText = $options["title"];
        }
        if (empty($titleText) && (!isset($options["disableAutoTitle"]) || !$options["disableAutoTitle"])) {
            if ($image->getMetadata("title")) {
                $titleText = $image->getMetadata("title");
            }
        }
        if (empty($altText) && (!isset($options["disableAutoAlt"]) || !$options["disableAutoAlt"])) {
            if ($image->getMetadata("alt")) {
                $altText = $image->getMetadata("alt");
            } else {
                $altText = $titleText;
            }
        }
        // get copyright from asset
        if ($image->getMetadata("copyright") && (!isset($options["disableAutoCopyright"]) || !$options["disableAutoCopyright"])) {
            if (!empty($altText)) {
                $altText .= " | ";
            }
            if (!empty($titleText)) {
                $titleText .= " | ";
            }
            $altText .= "© " . $image->getMetadata("copyright");
            $titleText .= "© " . $image->getMetadata("copyright");
        }
        $options["alt"] = $altText;
        if (!empty($titleText)) {
            $options["title"] = $titleText;
        }
        $attributesRaw = array_merge($options, $customAttributes);
        foreach ($attributesRaw as $key => $value) {
            if (!(is_string($value) || is_numeric($value) || is_bool($value))) {
                continue;
            }
            if (!(in_array($key, $w3cImgAttributes) || array_key_exists($key, $customAttributes) || strpos($key, "data-") === 0)) {
                continue;
            }
            //only include attributes with characters a-z and dashes in their name.
            if (preg_match("/^[a-z-]+\$/i", $key)) {
                $attributes[$key] = $key . '="' . htmlspecialchars($value) . '"';
                // do not include all attributes
                if (!in_array($key, ["width", "height", "alt"])) {
                    $pictureAttribs[$key] = $key . '="' . htmlspecialchars($value) . '"';
                }
                // some attributes need to be added also as data- attribute, this is specific to picturePolyfill
                if (in_array($key, ["alt"])) {
                    $pictureAttribs["data-" . $key] = "data-" . $key . '="' . htmlspecialchars($value) . '"';
                }
            }
        }
        $path = $this->getPath(true);
        $attributes['src'] = 'src="' . $path . '"';
        $thumbConfig = $this->getConfig();
        if ($this->getConfig() && !$this->getConfig()->hasMedias()) {
            // generate the srcset
            $srcSetValues = [];
            foreach ([1, 2] as $highRes) {
                $thumbConfigRes = clone $thumbConfig;
                $thumbConfigRes->setHighResolution($highRes);
                $srcsetEntry = $image->getThumbnail($thumbConfigRes, true) . " " . $highRes . "x";
                $srcSetValues[] = $srcsetEntry;
            }
            $attributes['srcset'] = 'srcset="' . implode(", ", $srcSetValues) . '"';
        }
        foreach ($removeAttributes as $attribute) {
            unset($attributes[$attribute]);
            unset($pictureAttribs[$attribute]);
        }
        // build html tag
        $htmlImgTag = '<img ' . implode(' ', $attributes) . ' />';
        // $this->getConfig() can be empty, the original image is returned
        if (!$this->getConfig() || !$this->getConfig()->hasMedias()) {
            return $htmlImgTag;
        } else {
            // output the <picture> - element
            // set this variable so that Pimcore_Controller_Plugin_Thumbnail::dispatchLoopShutdown() knows that
            // the picture polyfill script needs to be included
            self::$pictureElementInUse = true;
            // mobile first => fallback image is the smallest possible image
            $fallBackImageThumb = null;
            $html = '<picture ' . implode(" ", $pictureAttribs) . ' data-default-src="' . $path . '">' . "\n";
            $mediaConfigs = $thumbConfig->getMedias();
            // currently only max-width is supported, the key of the media is WIDTHw (eg. 400w) according to the srcset specification
            ksort($mediaConfigs, SORT_NUMERIC);
            array_push($mediaConfigs, $thumbConfig->getItems());
            //add the default config at the end - picturePolyfill v4
            foreach ($mediaConfigs as $mediaQuery => $config) {
                $srcSetValues = [];
                foreach ([1, 2] as $highRes) {
                    $thumbConfigRes = clone $thumbConfig;
                    $thumbConfigRes->selectMedia($mediaQuery);
                    $thumbConfigRes->setHighResolution($highRes);
                    $thumb = $image->getThumbnail($thumbConfigRes, true);
                    $srcSetValues[] = $thumb . " " . $highRes . "x";
                    if (!$fallBackImageThumb) {
                        $fallBackImageThumb = $thumb;
                    }
                }
                $html .= "\t" . '<source srcset="' . implode(", ", $srcSetValues) . '"';
                if ($mediaQuery) {
                    // currently only max-width is supported, so we replace the width indicator (400w) out of the name
                    $maxWidth = str_replace("w", "", $mediaQuery);
                    $html .= ' media="(max-width: ' . $maxWidth . 'px)"';
                    $thumb->reset();
                }
                $html .= ' />' . "\n";
            }
            //$html .= "\t" . '<noscript>' . "\n\t\t" . $htmlImgTag . "\n\t" . '</noscript>' . "\n";
            $attrCleanedForPicture = $attributes;
            unset($attrCleanedForPicture["width"]);
            unset($attrCleanedForPicture["height"]);
            $attrCleanedForPicture["src"] = 'src="' . (string) $fallBackImageThumb . '"';
            $htmlImgTagForpicture = '<img ' . implode(' ', $attrCleanedForPicture) . ' />';
            $html .= $htmlImgTagForpicture . "\n";
            $html .= '</picture>' . "\n";
            return $html;
        }
    }

 /**
  * @see Document\Tag\TagInterface::frontend
  * @return string
  */
 public function frontend()
 {
     if (!is_array($this->options)) {
         $this->options = [];
     }
     $image = $this->getImage();
     if ($image instanceof Asset) {
         if (isset($this->options["thumbnail"]) && $this->options["thumbnail"] || $this->cropPercent) {
             // create a thumbnail first
             $autoName = false;
             $thumbConfig = $image->getThumbnailConfig($this->options["thumbnail"]);
             if (!$thumbConfig && $this->cropPercent) {
                 $thumbConfig = new Asset\Image\Thumbnail\Config();
             }
             if ($this->cropPercent) {
                 $this->applyCustomCropping($thumbConfig);
                 $autoName = true;
             }
             if (isset($this->options["highResolution"]) && $this->options["highResolution"] > 1) {
                 $thumbConfig->setHighResolution($this->options["highResolution"]);
             }
             // autogenerate a name for the thumbnail because it's different from the original
             if ($autoName) {
                 $hash = md5(Serialize::serialize($thumbConfig->getItems()));
                 $thumbConfig->setName($thumbConfig->getName() . "_auto_" . $hash);
             }
             $deferred = true;
             if (isset($this->options["deferred"])) {
                 $deferred = $this->options["deferred"];
             }
             $thumbnail = $image->getThumbnail($thumbConfig, $deferred);
         } else {
             // we're using the thumbnail class only to generate the HTML
             $thumbnail = new Asset\Image\Thumbnail($image);
         }
         $attributes = array_merge($this->options, ["alt" => $this->alt, "title" => $this->alt]);
         $removeAttributes = [];
         if (isset($this->options["removeAttributes"]) && is_array($this->options["removeAttributes"])) {
             $removeAttributes = $this->options["removeAttributes"];
         }
         // thumbnail's HTML is always generated by the thumbnail itself
         return $thumbnail->getHTML($attributes, $removeAttributes);
     }
 }