N°8771 - Add Symfony form component to iTop core (#760)

- Add Symfony Form Component
- Add Symfony CSRF security component
- Add iTop default form template
- Add Twig debug extension to Twig Environment
- Add iTop abstract controller facility to get form builder
- Add Twig filter to make trans an alias of dict_s filter

lib/symfony/form/ChoiceList/View/ChoiceListView.php

@@ -0,0 +1,57 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\ChoiceList\View;
+
+/**
+ * Represents a choice list in templates.
+ *
+ * A choice list contains choices and optionally preferred choices which are
+ * displayed in the very beginning of the list. Both choices and preferred
+ * choices may be grouped in {@link ChoiceGroupView} instances.
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+class ChoiceListView
+{
+    public $choices;
+    public $preferredChoices;
+
+    /**
+     * Creates a new choice list view.
+     *
+     * @param array<ChoiceGroupView|ChoiceView> $choices          The choice views
+     * @param array<ChoiceGroupView|ChoiceView> $preferredChoices the preferred choice views
+     */
+    public function __construct(array $choices = [], array $preferredChoices = [])
+    {
+        $this->choices = $choices;
+        $this->preferredChoices = $preferredChoices;
+    }
+
+    /**
+     * Returns whether a placeholder is in the choices.
+     *
+     * A placeholder must be the first child element, not be in a group and have an empty value.
+     */
+    public function hasPlaceholder(): bool
+    {
+        if ($this->preferredChoices) {
+            $firstChoice = reset($this->preferredChoices);
+
+            return $firstChoice instanceof ChoiceView && '' === $firstChoice->value;
+        }
+
+        $firstChoice = reset($this->choices);
+
+        return $firstChoice instanceof ChoiceView && '' === $firstChoice->value;
+    }
+}