(mvc) add support class for easy datagrid usage

// create a new model
$model = new Model();
// link model to support class
$grid = new UIModelGrid($model->container->arrayTypeObject);
// fetch data and return into array which our frontend grid component can use
$result = $grid->fetch($fields, $itemsPerPage, $currentPage, $sortBy, $sortDescending, $searchPhrase);

src/opnsense/mvc/app/library/OPNsense/Base/UIModelGrid.php

+<?php
+/**
+ *    Copyright (C) 2015 Deciso B.V.
+ *
+ *    All rights reserved.
+ *
+ *    Redistribution and use in source and binary forms, with or without
+ *    modification, are permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice,
+ *       this list of conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *
+ *    THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ *    INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ *    AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ *    AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+ *    OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *    POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+namespace OPNsense\Base;
+
+/**
+ * Class UIModelGrid Grid control support functions
+ * @package OPNsense\Base
+ */
+class UIModelGrid
+{
+    /**
+     * @var null|FieldTypes\ArrayField Data provider to link Grid support functions to.
+     */
+    private $DataField = null;
+
+    /**
+     * @param FieldTypes\ArrayField $DataField
+     */
+    public function __construct($DataField)
+    {
+        $this->DataField = $DataField;
+    }
+
+    /**
+     * Fetch data from Array type field (Base\FieldTypes\ArrayField), sorted by specified fields and optionally filtered
+     * @param array $fields select fieldnames
+     * @param int $itemsPerPage number of items per page
+     * @param int $currentPage current selected page
+     * @param array $sortBy sort by fieldnames
+     * @param bool $sortDescending sort in descending order
+     * @param string $searchPhrase search phrase to use
+     * @return array
+     */
+    public function fetch($fields, $itemsPerPage, $currentPage, $sortBy = array(), $sortDescending = false, $searchPhrase = '')
+    {
+        $result = array('rows'=>array());
+
+        $recordIndex = 0;
+        foreach ($this->DataField->sortedBy($sortBy, $sortDescending) as $record) {
+            // parse rows, because we may need to convert some (list) items we need to know the actual content
+            // before searching.
+            $row =  array();
+            $row['uuid'] = $record->getAttributes()['uuid'];
+            foreach ($fields as $fieldname) {
+                $row[$fieldname] = $record->$fieldname->getNodeData();
+                if (is_array($row[$fieldname])) {
+                    foreach ($row[$fieldname] as $fieldKey => $fieldValue) {
+                        if ($fieldValue['selected'] == 1) {
+                            $row[$fieldname] = $fieldValue['value'];
+                        }
+                    }
+                }
+            }
+
+            // if a search phrase is provided, use it to search in all requested fields
+            if ($searchPhrase != '') {
+                $searchFound = false;
+                foreach ($fields as $fieldname) {
+                    if (strpos(strtolower($row[$fieldname]), strtolower($searchPhrase)) !== false) {
+                        $searchFound = true;
+                        break;
+                    }
+                }
+            } else {
+                $searchFound = true;
+            }
+
+            // if result is relevant, count total and add (max number of) items to result.
+            if ($searchFound) {
+                if (count($result['rows']) < $itemsPerPage &&
+                    $recordIndex >= ($itemsPerPage*($currentPage-1))
+                ) {
+                    $result['rows'][] = $row;
+                }
+                $recordIndex++;
+            }
+        }
+
+        $result['rowCount'] = count($result['rows']);
+        $result['total'] = $recordIndex;
+        $result['current'] = (int)$currentPage;
+
+        return $result;
+    }
+
+}
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