From f8e8a8dc2a2f1a331677171fb9dea52fc95aae4e Mon Sep 17 00:00:00 2001
From: Ivan Barlog <ivan.barlog@everlution.sk>
Date: Tue, 24 Oct 2017 02:33:32 +0200
Subject: [PATCH] add BaseDataSource

---
 README.md                         | 43 +++++++++++++++++++++++++++++++
 src/DataSource/BaseDataSource.php | 43 +++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+)
 create mode 100644 src/DataSource/BaseDataSource.php

diff --git a/README.md b/README.md
index 7cddc20..41cd7c7 100644
--- a/README.md
+++ b/README.md
@@ -231,6 +231,49 @@ class CustomForm extends AbstractType {
 }
 ```
 
+# Reusing data sources
+
+In order to reuse data source between for instance multiple tabs you can easily create Twig functions by extending our `BaseDataSource`.
+
+Simply add to your services.yml following statement:
+
+```yaml
+    AppBundle\DataProvider\:
+        resource: '../../src/AppBundle/DataProvider'
+        tags: ['twig.extension']
+```
+
+You can specify any folder within your project you want. In this example we have chosen `AppBundle\DataProvider` namespace.
+
+Each class within this namespace which extends `Everlution\AjaxcomBundle\DataSource\BaseDataSource` is scanned for public methods with suffix `Provider` via reflexion and we are creating the simple Twig functions from these methods. Let's see the example:
+
+
+```php
+// AppBundle\DataProvider\Example.php
+
+// simple function which returns static array
+public function navigationProvider() {
+    return [ 
+        // some data... 
+    ];
+}
+
+// you can use parametrical functions and injected services as well
+public function userProfileProvider(int $id) {
+    return $this->someService->getData($id);
+}
+```
+
+After creating such class you can simply call the function within twig:
+
+```twig
+{{ dump(navigation()); }} {# will dump static array #}
+
+{% for item in userProfile(2) %}
+   {{ dump(item) }}
+{% endfor %}
+```
+
 # Best practice
 
 If you want to use AjaxcomBundle seamlessly you should copy `@EverlutionAjaxcom\layout_bootstrap_4.html.twig` to your project (eg. AppBundle) and modify it to your needs.
diff --git a/src/DataSource/BaseDataSource.php b/src/DataSource/BaseDataSource.php
new file mode 100644
index 0000000..f15e69f
--- /dev/null
+++ b/src/DataSource/BaseDataSource.php
@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Everlution\AjaxcomBundle\DataSource;
+
+/**
+ * Class BaseDataSource.
+ *
+ * @author Ivan Barlog <ivan.barlog@everlution.sk>
+ */
+class BaseDataSource extends \Twig_Extension
+{
+    protected const TWIG_FUNCTION_SUFFIX = 'Provider';
+
+    /**
+     * @return array
+     */
+    public function getFunctions()
+    {
+        $functions = [];
+        $class = new \ReflectionClass(get_class($this));
+
+        if (self::class === $class->name) {
+            return $functions;
+        }
+
+        foreach ($class->getMethods(\ReflectionMethod::IS_PUBLIC) as $method) {
+            if (false === ($offset = strpos($method->getName(), self::TWIG_FUNCTION_SUFFIX))) {
+                continue;
+            }
+
+            $functions[] = $this->registerAsTwigFunction(substr($method->getName(), 0, $offset));
+        }
+
+        return $functions;
+    }
+
+    private function registerAsTwigFunction(string $name): ?\Twig_SimpleFunction
+    {
+        return new \Twig_SimpleFunction($name, [$this, $name.self::TWIG_FUNCTION_SUFFIX]);
+    }
+}