Display list of elements grouped by year and by month in TYPO3 Fluid

Question

I have a model where one field is a date. I want to display elements from that model, grouped by year and by month, like this:

== 2013 ==
=== April ===
* Ele         


        

Answer 1

Finally, I solved this problem by using a custom ViewHelper, derived from GroupedBy ViewHelper, inspired from https://gist.github.com/daKmoR/1287203, and adapted for extbase.

---

Here is the complete code for the ViewHelper, located in MyExt/Classes/ViewHelpers/GropuedForDateTimeViewHelper.php

 * // $items = array(
 * //   array('name' => 'apple', 'start' => DateTimeObject[2011-10-13 00:15:00]), 
 * //   array('name' => 'orange', 'start' => DateTimeObject[2011-12-01 00:10:00]),
 * //   array('name' => 'banana', 'start' => DateTimeObject[2008-05-24 00:40:00])
 * // );
 * 
 *   {year -> f:format.date(format: 'Y')}
 *   
 *     {item.name}
 *   
 * 
 * 
 *
 * Output:
 * 2011
 *   apple
 *   orange
 * 2010
 *   banana
 *
 * @license http://www.gnu.org/licenses/lgpl.html GNU Lesser General Public License, version 3 or later
 * @api
 */
class GroupedForDateTimeViewHelper extends \TYPO3\CMS\Fluid\Core\ViewHelper\AbstractViewHelper {

    /**
     * Iterates through elements of $each and renders child nodes
     *
     * @param array $each The array or Tx_Extbase_Persistence_ObjectStorage to iterated over
     * @param string $as The name of the iteration variable
     * @param string $groupBy Group by this property
     * @param string $groupKey The name of the variable to store the current group
     * @param string $format The format for the datetime
     * @param string $dateTimeKey The name of the variable to store the current datetime
     * @throws \TYPO3\CMS\Fluid\Core\ViewHelper\Exception
     * @return string Rendered string
     * @author Bastian Waidelich 
     * @author Thomas Allmer 
     * @api
     */
    public function render($each, $as, $groupBy, $groupKey = 'groupKey', $format = '', $dateTimeKey = 'dateTimeKey') {
        $output = '';
        if ($each === NULL) {
            return '';
        }

        if (is_object($each)) {
            if (!$each instanceof \Traversable) {
                throw new \TYPO3\CMS\Fluid\Core\ViewHelper\Exception('GroupedForViewHelper only supports arrays and objects implementing Traversable interface' , 1253108907);
            }
            $each = iterator_to_array($each);
        }

        $groups = $this->groupElements($each, $groupBy, $format);

        foreach ($groups['values'] as $currentGroupIndex => $group) {
            $this->templateVariableContainer->add($groupKey, $groups['keys'][$currentGroupIndex]);
            $this->templateVariableContainer->add($dateTimeKey, $groups['dateTimeKeys'][$currentGroupIndex]);
            $this->templateVariableContainer->add($as, $group);
            $output .= $this->renderChildren();
            $this->templateVariableContainer->remove($groupKey);
            $this->templateVariableContainer->remove($dateTimeKey);
            $this->templateVariableContainer->remove($as);
        }
        return $output;
    }

    /**
     * Groups the given array by the specified groupBy property and format for the datetime.
     *
     * @param array $elements The array / traversable object to be grouped
     * @param string $groupBy Group by this property
     * @param string $format The format for the datetime
     * @throws \TYPO3\CMS\Fluid\Core\ViewHelper\Exception
     * @return array The grouped array in the form array('keys' => array('key1' => [key1value], 'key2' => [key2value], ...), 'values' => array('key1' => array([key1value] => [element1]), ...), ...)
     * @author Bastian Waidelich 
     */
    protected function groupElements(array $elements, $groupBy, $format) {
        $groups = array('keys' => array(), 'values' => array());
        foreach ($elements as $key => $value) {
            if (is_array($value)) {
                $currentGroupIndex = isset($value[$groupBy]) ? $value[$groupBy] : NULL;
            } elseif (is_object($value)) {
                $currentGroupIndex = \TYPO3\CMS\Extbase\Reflection\ObjectAccess::getPropertyPath($value, $groupBy);
            } else {
                throw new \TYPO3\CMS\Fluid\Core\ViewHelper\Exception('GroupedForViewHelper only supports multi-dimensional arrays and objects' , 1253120365);
            }
            if (strpos($format, '%') !== FALSE) {
                $formatedDatetime = strftime($format, $currentGroupIndex->format('U'));
            } else {
                $formatedDatetime = $currentGroupIndex->format($format);
            }
            $groups['dateTimeKeys'][$formatedDatetime] = $currentGroupIndex;

            if (strpos($format, '%') !== FALSE) {
                $currentGroupIndex = strftime($format, $currentGroupIndex->format('U'));
            } else {
                $currentGroupIndex = $currentGroupIndex->format($format);
            }

            $currentGroupKeyValue = $currentGroupIndex;
            if (is_object($currentGroupIndex)) {
                $currentGroupIndex = spl_object_hash($currentGroupIndex);
            }
            $groups['keys'][$currentGroupIndex] = $currentGroupKeyValue;
            $groups['values'][$currentGroupIndex][$key] = $value;
        }
        return $groups;
    }
}

?>

---

And here is an example of a template using it:

{namespace m=vendor\MyExt\ViewHelpers}



    
        
{year}
        
            
{month}
            

            
                
{myitem}