Add FlashMessage utility class.

src/Http/FlashMessage.php

@@ -0,0 +1,195 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
+ * Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * For full copyright and license information, please see the LICENSE.txt
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @copyright     Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
+ * @link          https://cakephp.org CakePHP(tm) Project
+ * @since         4.2.0
+ * @license       https://opensource.org/licenses/mit-license.php MIT License
+ */
+namespace Cake\Http;
+
+use Cake\Core\InstanceConfigTrait;
+use Cake\Utility\Hash;
+use Throwable;
+
+/**
+ * The FlashMessage class provides a way for you to write a flash variable
+ * to the session, to be rendered in a view with the FlashHelper.
+ */
+class FlashMessage
+{
+    use InstanceConfigTrait;
+
+    /**
+     * Default configuration
+     *
+     * @var array
+     */
+    protected $_defaultConfig = [
+        'key' => 'flash',
+        'element' => 'default',
+        'params' => [],
+        'clear' => false,
+        'duplicate' => true,
+    ];
+
+    /**
+     * @var \Cake\Http\Session
+     */
+    protected $session;
+
+    /**
+     * Constructor
+     *
+     * @param \Cake\Http\Session $session Session instance.
+     * @param array $config Config array.
+     * @see FlashMessage::set() For list of valid config keys.
+     */
+    public function __construct(Session $session, array $config = [])
+    {
+        $this->session = $session;
+        $this->setConfig($config);
+    }
+
+    /**
+     * Used to set a session variable that can be used to output messages in the view.
+     * If you make consecutive calls to this method, the messages will stack
+     * (if they are set with the same flash key)
+     *
+     * ### Options:
+     *
+     * - `key` The key to set under the session's Flash key.
+     * - `element` The element used to render the flash message.
+     * - `params` An array of variables to be made available to the element.
+     * - `clear` A bool stating if the current stack should be cleared to start a new one.
+     * - `escape` Set to false to allow templates to print out HTML content.
+     *
+     * @param string $message Message to be flashed.
+     * @param array $options An array of options
+     * @return void
+     * @see FlashMessage::$_defaultConfig For default values for the options.
+     */
+    public function set($message, array $options = []): void
+    {
+        $options = Hash::merge((array)$this->getConfig(), $options);
+
+        if (isset($options['escape']) && !isset($options['params']['escape'])) {
+            $options['params']['escape'] = $options['escape'];
+        }
+
+        [$plugin, $element] = pluginSplit($options['element']);
+
+        if ($plugin) {
+            $options['element'] = $plugin . '.flash/' . $element;
+        } else {
+            $options['element'] = 'flash/' . $element;
+        }
+
+        $messages = [];
+        if (!$options['clear']) {
+            $messages = (array)$this->session->read('Flash.' . $options['key']);
+        }
+
+        if (!$options['duplicate']) {
+            foreach ($messages as $existingMessage) {
+                if ($existingMessage['message'] === $message) {
+                    return;
+                }
+            }
+        }
+
+        $messages[] = [
+            'message' => $message,
+            'key' => $options['key'],
+            'element' => $options['element'],
+            'params' => $options['params'],
+        ];
+
+        $this->session->write('Flash.' . $options['key'], $messages);
+    }
+
+    /**
+     * Set an exception's message as flash message.
+     *
+     * The following options will be set by default if unset:
+     * ```
+     * 'element' => 'error',
+     * `params' => ['code' => $exception->getCode()]
+     * ```
+     *
+     * @param \Throwable $exception Exception instance.
+     * @param array $options An array of options.
+     * @return void
+     * @see FlashMessage::set() For list of valid options
+     */
+    public function setExceptionMessage(Throwable $exception, array $options = []): void
+    {
+        if (!isset($options['element'])) {
+            $options['element'] = 'error';
+        }
+        if (!isset($options['params']['code'])) {
+            $options['params']['code'] = $exception->getCode();
+        }
+
+        $message = $exception->getMessage();
+        $this->set($message, $options);
+    }
+
+    /**
+     * Get the messages for given key and remove from session.
+     *
+     * @param string $key The key for get messages for.
+     * @return array|null
+     */
+    public function consume(string $key): ?array
+    {
+        $messages = $this->session->read("Flash.{$key}");
+        if ($messages !== null) {
+            $this->session->delete("Flash.{$key}");
+        }
+
+        return $messages;
+    }
+
+    /**
+     * Set a success message.
+     *
+     * The `'element'` option will be set to  `'success'`.
+     *
+     * @param string $message Message to flash.
+     * @param array $options An array of options.
+     * @return void
+     * @see FlashMessage::set() For list of valid options
+     */
+    public function success(string $message, array $options = []): void
+    {
+        $options['element'] = 'success';
+
+        $this->set($message, $options);
+    }
+
+    /**
+     * Set an success message.
+     *
+     * The `'element'` option will be set to  `'error'`.
+     *
+     * @param string $message Message to flash.
+     * @param array $options An array of options.
+     * @return void
+     * @see FlashMessage::set() For list of valid options
+     */
+    public function error(string $message, array $options = []): void
+    {
+        $options['element'] = 'error';
+
+        $this->set($message, $options);
+    }
+}

tests/TestCase/Http/FlashMessageTest.php

@@ -0,0 +1,291 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
+ * Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * For full copyright and license information, please see the LICENSE.txt
+ * Redistributions of files must retain the above copyright notice
+ *
+ * @copyright     Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
+ * @link          https://cakephp.org CakePHP(tm) Project
+ * @since         4.2.0
+ * @license       https://opensource.org/licenses/mit-license.php MIT License
+ */
+namespace Cake\Test\TestCase\Http;
+
+use Cake\Http\FlashMessage;
+use Cake\Http\Session;
+use Cake\TestSuite\TestCase;
+use Exception;
+
+/**
+ * FlashMessageTest class
+ */
+class FlashMessageTest extends TestCase
+{
+    /**
+     * @var \Cake\Http\FlashMessage
+     */
+    protected $Flash;
+
+    /**
+     * @var \Cake\Http\Session
+     */
+    protected $Session;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        static::setAppNamespace();
+        $this->Session = new Session();
+        $this->Flash = new FlashMessage($this->Session);
+    }
+
+    public function tearDown(): void
+    {
+        parent::tearDown();
+
+        $this->Session->destroy();
+    }
+
+    public function testSet(): void
+    {
+        $this->assertNull($this->Session->read('Flash.flash'));
+
+        $this->Flash->set('This is a test message');
+        $expected = [
+            [
+                'message' => 'This is a test message',
+                'key' => 'flash',
+                'element' => 'flash/default',
+                'params' => [],
+            ],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+
+        $this->Flash->set(
+            'This is a test message',
+            ['element' => 'test', 'params' => ['foo' => 'bar']]
+        );
+        $expected[] = [
+            'message' => 'This is a test message',
+            'key' => 'flash',
+            'element' => 'flash/test',
+            'params' => ['foo' => 'bar'],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+
+        $this->Flash->set('This is a test message', ['element' => 'MyPlugin.alert']);
+        $expected[] = [
+            'message' => 'This is a test message',
+            'key' => 'flash',
+            'element' => 'MyPlugin.flash/alert',
+            'params' => [],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+
+        $this->Flash->set('This is a test message', ['key' => 'foobar']);
+        $expected = [
+            [
+                'message' => 'This is a test message',
+                'key' => 'foobar',
+                'element' => 'flash/default',
+                'params' => [],
+            ],
+        ];
+        $result = $this->Session->read('Flash.foobar');
+        $this->assertEquals($expected, $result);
+    }
+
+    public function testDuplicateIgnored(): void
+    {
+        $this->assertNull($this->Session->read('Flash.flash'));
+
+        $this->Flash->setConfig('duplicate', false);
+        $this->Flash->set('This test message should appear once only');
+        $this->Flash->set('This test message should appear once only');
+        $result = $this->Session->read('Flash.flash');
+        $this->assertCount(1, $result);
+    }
+
+    public function testSetEscape(): void
+    {
+        $this->assertNull($this->Session->read('Flash.flash'));
+
+        $this->Flash->set(
+            'This is a <b>test</b> message',
+            ['escape' => false, 'params' => ['foo' => 'bar']]
+        );
+        $expected = [
+            [
+                'message' => 'This is a <b>test</b> message',
+                'key' => 'flash',
+                'element' => 'flash/default',
+                'params' => ['foo' => 'bar', 'escape' => false],
+            ],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+
+        $this->Flash->set(
+            'This is a test message',
+            ['key' => 'escaped', 'escape' => false, 'params' => ['foo' => 'bar', 'escape' => true]]
+        );
+        $expected = [
+            [
+                'message' => 'This is a test message',
+                'key' => 'escaped',
+                'element' => 'flash/default',
+                'params' => ['foo' => 'bar', 'escape' => true],
+            ],
+        ];
+        $result = $this->Session->read('Flash.escaped');
+        $this->assertEquals($expected, $result);
+    }
+
+    public function testSetWithClear(): void
+    {
+        $this->assertNull($this->Session->read('Flash.flash'));
+
+        $this->Flash->set('This is a test message');
+        $expected = [
+            [
+                'message' => 'This is a test message',
+                'key' => 'flash',
+                'element' => 'flash/default',
+                'params' => [],
+            ],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+
+        $this->Flash->set('This is another test message', ['clear' => true]);
+        $expected = [
+            [
+                'message' => 'This is another test message',
+                'key' => 'flash',
+                'element' => 'flash/default',
+                'params' => [],
+            ],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+    }
+
+    public function testSetExceptionMessage(): void
+    {
+        $this->assertNull($this->Session->read('Flash.flash'));
+
+        $this->Flash->setExceptionMessage(new Exception('This is a test message', 404));
+        $expected = [
+            [
+                'message' => 'This is a test message',
+                'key' => 'flash',
+                'element' => 'flash/error',
+                'params' => ['code' => 404],
+            ],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+
+        $this->Flash->setExceptionMessage(
+            new Exception('This is a test message'),
+            ['element' => 'default', 'clear' => true]
+        );
+        $expected = [
+            [
+                'message' => 'This is a test message',
+                'key' => 'flash',
+                'element' => 'flash/default',
+                'params' => ['code' => null],
+            ],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+    }
+
+    public function testSetWithConstructorConfiguration(): void
+    {
+        $this->assertNull($this->Session->read('Flash.flash'));
+
+        $flash = new FlashMessage($this->Session, ['element' => 'test']);
+        $flash->set('This is a test message');
+        $expected = [
+            [
+                'message' => 'This is a test message',
+                'key' => 'flash',
+                'element' => 'flash/test',
+                'params' => [],
+            ],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+    }
+
+    public function testSuccess(): void
+    {
+        $this->assertNull($this->Session->read('Flash.flash'));
+
+        $this->Flash->success('It worked');
+        $expected = [
+            [
+                'message' => 'It worked',
+                'key' => 'flash',
+                'element' => 'flash/success',
+                'params' => [],
+            ],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+    }
+
+    public function testSuccessWithClear(): void
+    {
+        $this->assertNull($this->Session->read('Flash.flash'));
+        $this->Flash->success('It worked');
+        $expected = [
+            [
+                'message' => 'It worked',
+                'key' => 'flash',
+                'element' => 'flash/success',
+                'params' => [],
+            ],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+        $this->Flash->success('It worked too', ['clear' => true]);
+        $expected = [
+            [
+                'message' => 'It worked too',
+                'key' => 'flash',
+                'element' => 'flash/success',
+                'params' => [],
+            ],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result);
+    }
+
+    public function testError(): void
+    {
+        $this->assertNull($this->Session->read('Flash.flash'));
+
+        $this->Flash->error('It did not work', ['element' => 'error_thing']);
+
+        $expected[] = [
+            'message' => 'It did not work',
+            'key' => 'flash',
+            'element' => 'flash/error',
+            'params' => [],
+        ];
+        $result = $this->Session->read('Flash.flash');
+        $this->assertEquals($expected, $result, 'Element is ignored in convenience method call.');
+    }
+}