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/DataTransformerInterface.php

@@ -0,0 +1,99 @@
+<?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;
+
+use Symfony\Component\Form\Exception\TransformationFailedException;
+
+/**
+ * Transforms a value between different representations.
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ *
+ * @template TValue
+ * @template TTransformedValue
+ */
+interface DataTransformerInterface
+{
+    /**
+     * Transforms a value from the original representation to a transformed representation.
+     *
+     * This method is called when the form field is initialized with its default data, on
+     * two occasions for two types of transformers:
+     *
+     * 1. Model transformers which normalize the model data.
+     *    This is mainly useful when the same form type (the same configuration)
+     *    has to handle different kind of underlying data, e.g The DateType can
+     *    deal with strings or \DateTime objects as input.
+     *
+     * 2. View transformers which adapt the normalized data to the view format.
+     *    a/ When the form is simple, the value returned by convention is used
+     *       directly in the view and thus can only be a string or an array. In
+     *       this case the data class should be null.
+     *
+     *    b/ When the form is compound the returned value should be an array or
+     *       an object to be mapped to the children. Each property of the compound
+     *       data will be used as model data by each child and will be transformed
+     *       too. In this case data class should be the class of the object, or null
+     *       when it is an array.
+     *
+     * All transformers are called in a configured order from model data to view value.
+     * At the end of this chain the view data will be validated against the data class
+     * setting.
+     *
+     * This method must be able to deal with empty values. Usually this will
+     * be NULL, but depending on your implementation other empty values are
+     * possible as well (such as empty strings). The reasoning behind this is
+     * that data transformers must be chainable. If the transform() method
+     * of the first data transformer outputs NULL, the second must be able to
+     * process that value.
+     *
+     * @param TValue|null $value The value in the original representation
+     *
+     * @return mixed
+     *
+     * @psalm-return TTransformedValue|null
+     *
+     * @throws TransformationFailedException when the transformation fails
+     */
+    public function transform(mixed $value);
+
+    /**
+     * Transforms a value from the transformed representation to its original
+     * representation.
+     *
+     * This method is called when {@link Form::submit()} is called to transform the requests tainted data
+     * into an acceptable format.
+     *
+     * The same transformers are called in the reverse order so the responsibility is to
+     * return one of the types that would be expected as input of transform().
+     *
+     * This method must be able to deal with empty values. Usually this will
+     * be an empty string, but depending on your implementation other empty
+     * values are possible as well (such as NULL). The reasoning behind
+     * this is that value transformers must be chainable. If the
+     * reverseTransform() method of the first value transformer outputs an
+     * empty string, the second value transformer must be able to process that
+     * value.
+     *
+     * By convention, reverseTransform() should return NULL if an empty string
+     * is passed.
+     *
+     * @param TTransformedValue|null $value The value in the transformed representation
+     *
+     * @return mixed
+     *
+     * @psalm-return TValue|null
+     *
+     * @throws TransformationFailedException when the transformation fails
+     */
+    public function reverseTransform(mixed $value);
+}