Added a new Collection::intersect() method #1605

CHANGELOG.md

@@ -7,6 +7,7 @@
     * Added new `onTwigLoader()` event to enable utilization of loader methods
     * Added new `Twig::addPath()` and `Twig::prependPath()` methods to wrap loader methods and support namespacing [#1604](https://github.com/getgrav/grav/issues/1604)
     * Added new `array_key_exists()` Twig function wrapper
+    * Added a new `Collection::intersect()` method [#1605](github.com/getgrav/grav/issues/1605)
 1. [](#bugfix)
     * Allow `session.timetout` field to be set to `0` via blueprints [#1598](https://github.com/getgrav/grav/issues/1598)
     * Fixed `Data::exists()` and `Data::raw()` functions breaking if `Data::file()` hasn't been called with non-null value

system/src/Grav/Common/Page/Collection.php

@@ -63,6 +63,20 @@ class Collection extends Iterator
         return $this;
     }
 
+    /**
+     * Add a page with path and slug
+     *
+     * @param $path
+     * @param $slug
+     * @return $this
+     */
+    public function add($path, $slug)
+    {
+        $this->items[$path] = ['slug' => $slug];
+
+        return $this;
+    }
+
     /**
      *
      * Create a copy of this collection
@@ -89,6 +103,23 @@ class Collection extends Iterator
         return $this;
     }
 
+    /**
+     * Intersect another collection with the current collection
+     *
+     * @param Collection $collection
+     * @return $this
+     */
+    public function intersect(Collection $collection)
+    {
+        $array1 = $this->items;
+        $array2 = $collection->toArray();
+
+        $this->items = array_uintersect($array1, $array2, function($val1, $val2) {
+            return strcmp($val1['slug'], $val2['slug']);
+        });
+        return $this;
+    }
+
     /**
      * Set parameters to the Collection
      *

system/src/Grav/Common/Twig/TwigExtension.php

@@ -9,6 +9,7 @@
 namespace Grav\Common\Twig;
 
 use Grav\Common\Grav;
+use Grav\Common\Page\Collection;
 use Grav\Common\Page\Media;
 use Grav\Common\Utils;
 use Grav\Common\Markdown\Parsedown;
@@ -94,6 +95,7 @@ class TwigExtension extends \Twig_Extension
             new \Twig_SimpleFilter('truncate_html', ['\Grav\Common\Utils', 'truncateHTML']),
             new \Twig_SimpleFilter('json_decode', [$this, 'jsonDecodeFilter']),
             new \Twig_SimpleFilter('array_unique', 'array_unique'),
+
         ];
     }
 
@@ -108,6 +110,7 @@ class TwigExtension extends \Twig_Extension
             new \Twig_SimpleFunction('array', [$this, 'arrayFunc']),
             new \Twig_SimpleFunction('array_key_value', [$this, 'arrayKeyValueFunc']),
             new \Twig_SimpleFunction('array_key_exists', [$this, 'arrayKeyExistsFunc']),
+            new \Twig_SimpleFunction('array_intersect', [$this, 'arrayIntersectFunc']),
             new \Twig_simpleFunction('authorize', [$this, 'authorize']),
             new \Twig_SimpleFunction('debug', [$this, 'dump'], ['needs_context' => true, 'needs_environment' => true]),
             new \Twig_SimpleFunction('dump', [$this, 'dump'], ['needs_context' => true, 'needs_environment' => true]),
@@ -832,6 +835,23 @@ class TwigExtension extends \Twig_Extension
         return array_key_exists($key, $current_array);
     }
 
+    /**
+     * Wrapper for array_intersect() method
+     *
+     * @param $array1
+     * @param $array2
+     * @return array
+     */
+    public function arrayIntersectFunc($array1, $array2)
+    {
+        if ($array1 instanceof Collection && $array2 instanceof Collection) {
+            return $array1->intersect($array2);
+        } else {
+            return array_intersect($array1, $array2);
+        }
+
+    }
+
     /**
      * Returns a string from a value. If the value is array, return it json encoded
      *