Viewhelper: File exsits.

Angabe des Namesspaces im Fluid Template:

{namespace fhs=Fischhase\FhViewhelpers\ViewHelpers}

Dann kann derViewhelper aufgerufen werden:

{fhs:fileexists(path:path, file:filename)}

path (String): absoluter Pfad, in dem die Daten liegt (fileadmin/theme/light/images/)
file (String): Dateiname, der geprüft werden soll.
return: Gibt FALSE aus, wenn die Datei nicht vorhanden ist oder den geprüften Pfad+Dateinamen zur Weiterverwendung

Der Pfad kann Schrägstriche am Anfang enthalten oder nicht. Der Viewhelper rückt es gerade und gibt den korrekten Pfad zurück.

Beispiel:

<f:variable name="file" value="icon_{category.description}.svg"  />                
<f:variable name="path" value="/fileadmin/theme/light/images/"  />                
<f:variable name="verifiedPath"><fhs:fileexists file="{file}" path="{path}"/></f:variable>

<f:if condition="{verifiedPath}">
   <f:then>
      <img src="{verifiedPath}" alt="{category.title}" width="360c" height="360c" />
   </f:then>
   <f:else>
      <div style="color:red; border:1px solid red; padding:0.5rem"> kein Icon zu Kategorie {category.uid} gefunden. Dateinamensegment muss in der Beschreibung stehen.<br />
   </f:else>                        
</f:if>

<?php

namespace Fischhase\FhViewhelpers\ViewHelpers;

use TYPO3\CMS\Core\Core\Environment;
use TYPO3Fluid\Fluid\Core\ViewHelper\AbstractViewHelper;
use TYPO3\CMS\Extbase\Utility\DebuggerUtility;  

/*
 *   {namespace fhs=Fischhase\FhViewhelpers\ViewHelpers}
 *
 *   {fhs:fileexists(path:path, file:filename)}
 *    the viewhelpers checks, if the path and filenames have the correct slashes. It returns the checked path/filename as string or FALSE, if the file does not exist.
*/

class FileexistsViewHelper extends AbstractViewHelper {
    /**
     * @params string $path (path)
     * @params string $file (filename)
     * @return bool/string (FALSE or path/filename)
     */

    public function initializeArguments() {
        $this->registerArgument('path', 'string', 'path of file', TRUE);
        $this->registerArgument('file', 'string', 'name of file', TRUE);
    }

    public function render() {
        $path = $this->arguments['path'];
        $file = $this->arguments['file'];
        $return = FALSE;

        /* checks slashes and adds missing*/
        if ($path) {
            if (mb_substr($path, 0, 1) != '/') {
                $path = '/' . $path;
            }
            if (mb_substr($path, -1) != '/') {
                $path = $path . '/';
            }        
        };

        if ($file) {
            /* checks slashes and removes excess slashes  */
            if (mb_substr($file, 0, 1) == '/') {
                $file = mb_substr($file, 1);
            }
        }

        /* get web root path */
        $root = Environment::getPublicPath();
        /*assemble full path */
        $fullpath = $root . $path . $file;
        if (file_exists($fullpath)) {
            /*returns path from web root */
            $return = $path . $file;
        }
        /*retunrs false if file does not exist */
        return $return;
    }
}