PodsForm::file_field_types PHP Method

    public static function file_field_types()
    {
        static $field_types = null;
        if (null === $field_types) {
            $field_types = array('file', 'avatar');
            $field_types = apply_filters('pods_file_field_types', $field_types);
        }
        return $field_types;
    }

/**
 * Split an array into human readable text (Item, Item, and Item)
 *
 * @param array $value
 * @param string $field
 * @param array $fields
 * @param string $and
 * @param string $field_index
 *
 * @return string
 *
 * @since 2.0
 */
function pods_serial_comma($value, $field = null, $fields = null, $and = null, $field_index = null)
{
    if (is_object($value)) {
        $value = get_object_vars($value);
    }
    $defaults = array('field' => $field, 'fields' => $fields, 'and' => $and, 'field_index' => $field_index, 'separator' => ',', 'serial' => true);
    if (is_array($field)) {
        $defaults['field'] = null;
        $params = array_merge($defaults, $field);
    } else {
        $params = $defaults;
    }
    $params = (object) $params;
    $simple = false;
    if (!empty($params->fields) && is_array($params->fields) && isset($params->fields[$params->field])) {
        $params->field = $params->fields[$params->field];
        $simple_tableless_objects = PodsForm::simple_tableless_objects();
        if (!empty($params->field) && is_array($params->field) && in_array($params->field['type'], PodsForm::tableless_field_types())) {
            if (in_array($params->field['type'], PodsForm::file_field_types())) {
                if (null === $params->field_index) {
                    $params->field_index = 'guid';
                }
            } elseif (in_array($params->field['pick_object'], $simple_tableless_objects)) {
                $simple = true;
            } else {
                $table = pods_api()->get_table_info($params->field['pick_object'], $params->field['pick_val'], null, null, $params->field);
                if (!empty($table)) {
                    if (null === $params->field_index) {
                        $params->field_index = $table['field_index'];
                    }
                }
            }
        }
    } else {
        $params->field = null;
    }
    if ($simple && is_array($params->field) && !is_array($value) && '' !== $value && null !== $value) {
        $value = PodsForm::field_method('pick', 'simple_value', $params->field['name'], $value, $params->field);
    }
    if (!is_array($value)) {
        return $value;
    }
    if (null === $params->and) {
        $params->and = ' ' . __('and', 'pods') . ' ';
    }
    $last = '';
    $original_value = $value;
    if (!empty($value)) {
        $last = array_pop($value);
    }
    if ($simple && is_array($params->field) && !is_array($last) && '' !== $last && null !== $last) {
        $last = PodsForm::field_method('pick', 'simple_value', $params->field['name'], $last, $params->field);
    }
    if (is_array($last)) {
        if (null !== $params->field_index && isset($last[$params->field_index])) {
            $last = $last[$params->field_index];
        } elseif (isset($last[0])) {
            $last = $last[0];
        } elseif ($simple) {
            $last = current($last);
        } else {
            $last = '';
        }
    }
    if (!empty($value)) {
        if (null !== $params->field_index && isset($original_value[$params->field_index])) {
            return $original_value[$params->field_index];
        } elseif (null !== $params->field_index && isset($value[$params->field_index])) {
            return $value[$params->field_index];
        } elseif (!isset($value[0])) {
            $value = array($value);
        }
        foreach ($value as $k => $v) {
            if ($simple && is_array($params->field) && !is_array($v) && '' !== $v && null !== $v) {
                $v = PodsForm::field_method('pick', 'simple_value', $params->field['name'], $v, $params->field);
            }
            if (is_array($v)) {
                if (null !== $params->field_index && isset($v[$params->field_index])) {
                    $v = $v[$params->field_index];
                } elseif ($simple) {
                    $v = trim(implode($params->separator . ' ', $v), $params->separator . ' ');
                } else {
                    unset($value[$k]);
                    continue;
                }
            }
            $value[$k] = $v;
        }
        if (1 == count($value) || !$params->serial) {
            $value = trim(implode($params->separator . ' ', $value), $params->separator . ' ');
        } else {
            $value = trim(implode($params->separator . ' ', $value), $params->separator . ' ') . apply_filters('pods_serial_comma', $params->separator . ' ', $value, $original_value, $params);
        }
        $value = trim($value);
        $last = trim($last);
        if (0 < strlen($value) && 0 < strlen($last)) {
            $value = $value . $params->and . $last;
        } elseif (0 < strlen($last)) {
            $value = $last;
        } else {
            $value = '';
        }
    } else {
        $value = $last;
    }
    $value = trim($value, $params->separator . ' ');
    $value = apply_filters('pods_serial_comma_value', $value, $original_value, $params);
    return (string) $value;
}