1 files changed, 184 insertions, 0 deletions
diff --git a/lib/trails/Flash.php b/lib/trails/Flash.php
new file mode 100644
index 0000000..eede7af
--- /dev/null
+++ b/lib/trails/Flash.php
@@ -0,0 +1,184 @@
+<?php
+
+namespace Trails;
+
+use Trails\Exceptions\SessionRequiredException;
+
+/**
+ * The flash provides a way to pass temporary objects between actions.
+ * Anything you place in the flash will be exposed to the very next action and
+ * then cleared out. This is a great way of doing notices and alerts, such as
+ * a create action that sets
+ * <tt>$flash->set('notice', "Successfully created")</tt>
+ * before redirecting to a display action that can then expose the flash to its
+ * template.
+ *
+ * @package       trails
+ *
+ * @author        mlunzena
+ * @copyright (c) Authors
+ * @version       $Id: trails.php 7001 2008-04-04 11:20:27Z mlunzena $
+ */
+final class Flash implements \ArrayAccess
+{
+    private array $flash = [];
+    private array $used = [];
+
+    /**
+     * @return self
+     * @throws SessionRequiredException
+     */
+    public static function instance()
+    {
+        if (!isset($_SESSION)) {
+            throw new Exceptions\SessionRequiredException();
+        }
+
+        if (!isset($_SESSION[self::class])) {
+            $_SESSION[self::class] = new self();
+        }
+        return $_SESSION[self::class];
+    }
+
+    public function offsetExists($offset): bool
+    {
+        return isset($this->flash[$offset]);
+    }
+
+    public function offsetGet($offset): mixed
+    {
+        return $this->get($offset);
+    }
+
+    public function offsetSet($offset, $value): void
+    {
+        $this->set($offset, $value);
+    }
+
+    public function offsetUnset($offset): void
+    {
+        unset($this->flash[$offset], $this->used[$offset]);
+    }
+
+    /**
+     * Used internally by the <tt>keep</tt> and <tt>discard</tt> methods
+     *     use()               # marks the entire flash as used
+     *     use('msg')          # marks the "msg" entry as used
+     *     use(null, false)    # marks the entire flash as unused
+     *                         # (keeps it around for one more action)
+     *     use('msg', false)   # marks the "msg" entry as unused
+     *                         # (keeps it around for one more action)
+     *
+     */
+    private function use(?string $key = null, bool $isUsed = true): void
+    {
+        if ($key) {
+            $this->used[$key] = $isUsed;
+        } else {
+            foreach (array_keys($this->used) as $key) {
+                $this->use($key, $isUsed);
+            }
+        }
+    }
+
+    /**
+     * Marks the entire flash or a single flash entry to be discarded by the end
+     * of the current action.
+     *
+     *     $flash->discard()             # discards entire flash
+     *                                   # (it'll still be available for the
+     *                                   # current action)
+     *     $flash->discard('warning')    # discard the "warning" entry
+     *                                   # (it'll still be available for the
+     *                                   # current action)
+     */
+    public function discard(?string $key = null): void
+    {
+        $this->use($key);
+    }
+
+    /**
+     * Returns the value to the specified key.
+     *
+     * @return mixed the key's value.
+     */
+    public function &get(string $key): mixed
+    {
+        $return = null;
+        if (isset($this->flash[$key])) {
+            $return =& $this->flash[$key];
+        }
+        return $return;
+    }
+
+    /**
+     * Keeps either the entire current flash or a specific flash entry available
+     * for the next action:
+     *
+     *    $flash->keep()           # keeps the entire flash
+     *    $flash->keep('notice')   # keeps only the "notice" entry, the rest of
+     *                             # the flash is discarded
+     */
+    public function keep(?string $key = null): void
+    {
+        $this->use($key, false);
+    }
+
+    /**
+     * Sets a key's value.
+     */
+    public function set(string $key, mixed $value): void
+    {
+        $this->keep($key);
+        $this->flash[$key] = $value;
+    }
+
+    /**
+     * Sets a key's value by reference.
+     */
+    public function set_ref(string $key, mixed &$value): void
+    {
+        $this->keep($key);
+        $this->flash[$key] =& $valze;
+    }
+
+    /**
+     * Removes all used values
+     */
+    public function sweep(): void
+    {
+        foreach (array_keys($this->flash) as $k) {
+            if ($this->used[$k]) {
+                unset($this->flash[$k], $this->used[$k]);
+            } else {
+                $this->use($k);
+            }
+        }
+    }
+
+    public function __toString()
+    {
+        $values = [];
+        foreach ($this->flash as $key => $value) {
+            $values[] = sprintf(
+                "'%s': [%s, '%s']",
+                $key,
+                var_export($value, true),
+                !empty($this->used[$key]) ? 'used' : 'unused'
+            );
+        }
+        return '{' . implode(', ', $values) . '}'. "\n";
+    }
+
+    public function __sleep(): array
+    {
+        $this->sweep();
+        return ['flash', 'used'];
+    }
+
+
+    public function __wakeUp()
+    {
+        $this->discard();
+    }
+}