Custom Filters

• Predefined filter methods
• Define your own method
• Supporting the split argument

You can filter lists of pages, files, users or languages with a set of predefined filter methods. This set can be extended with your own filters.

Predefined filter methods

The best place to define those extended filter methods is in a plugin file.
For example: /site/plugins/filters.php

Define your own method

// anything that starts with the given value
collection::$filters['^='] = function($collection, $field, $value) {

  foreach($collection->data as $key => $item) {
    if(str::startsWith(collection::extractValue($item, $field), $value)) continue;
    unset($collection->$key);
  }

  return $collection;

};

collection::extractValue($item, $field)

You might have noticed this static method in the example above. This method helps to extract the correct value by field from the given $item, no matter if the item is an array or an object.

Supporting the split argument

When you use the filterBy() method for a collection you can pass a split separator as last argument, which makes it possible to apply the filter to fields with comma separated values for example.

Example

$articles = $page->children()->filterBy('tags', 'design', ',');

To support this split parameter in your own filter you have to extend it a bit.

// anything that starts with the given value
collection::$filters['^='] = function($collection, $field, $value, $split = false) {

  foreach($collection->data as $key => $item) {
    if($split) {
      $values = str::split((string)collection::extractValue($item, $field), $split);
      foreach($values as $val) {
        if(str::startsWith($val, $value) === false) {
          unset($collection->$key);
          break;
        }
      }
    } else if(str::startsWith(collection::extractValue($item, $field), $value) === false) {
      unset($collection->$key);
    }
  }

  return $collection;

};