added stacked data

demo/bootstrap.php

@@ -2,6 +2,9 @@
 
 include __DIR__ . '/../tests/bootstrap.php';
 
+// for stack data
+session_start();
+
 use DebugBar\StandardDebugBar;
 
 $debugbar = new StandardDebugBar();

demo/index.php

@@ -25,6 +25,10 @@ render_demo_page(function() {
     <li><a href="ajax.php" class="ajax">load ajax content</a></li>
     <li><a href="ajax_exception.php" class="ajax">load ajax content with exception</a></li>
 </ul>
+<h2>Stack</h2>
+<ul>
+    <li><a href="stack.php">perform a redirect</a></li>
+</ul>
 <h2>PDO</h2>
 <ul>
     <li><a href="pdo.php">PDO demo</a></li>

demo/stack.php

@@ -0,0 +1,6 @@
+<?php
+
+include 'bootstrap.php';
+$debugbar['messages']->addMessage('hello from redirect');
+$debugbar->stackData();
+header('Location: index.php');

docs/ajax.md

@@ -1,24 +0,0 @@
-# AJAX
-
-As mentioned in the previous chapter, if you are performing AJAX requests
-which return HTML content, you can use `JavascriptRenderer::render(false)`.
-
-In the case you are sending back non-HTML data (eg: JSON), the DebugBar can 
-send data to the client using HTTP headers using the `sendDataInHeaders()` method
-(no need to use the `JavascriptRenderer`):
-
-    $debugbar = new DebugBar();
-    // ...
-    $debugbar->sendDataInHeaders();
-
-On the client side, an instance of `PhpDebugBar.AjaxHandler` will
-parse the headers and add the dataset to the debugbar.
-
-The AjaxHandler automatically binds to jQuery's *ajaxComplete* event
-so if you are using jQuery, you have nothing to configure.
-
-If you're not using jQuery, you can call `AjaxHandler.handle(xhr)`.
-If you are using the `JavascriptRenderer` initialization, the instance 
-of `AjaxHandler` is stored in the `ajaxHandler` property of the `DebugBar` object.
-
-    debugbar.ajaxHandler.handle(xhr);

docs/ajax_and_stack.md

@@ -0,0 +1,49 @@
+# AJAX and Stacked data
+
+## AJAX
+
+As mentioned in the previous chapter, if you are performing AJAX requests
+which return HTML content, you can use `JavascriptRenderer::render(false)`.
+
+In the case you are sending back non-HTML data (eg: JSON), the DebugBar can 
+send data to the client using HTTP headers using the `sendDataInHeaders()` method
+(no need to use the `JavascriptRenderer`):
+
+    $debugbar = new DebugBar();
+    // ...
+    $debugbar->sendDataInHeaders();
+
+On the client side, an instance of `PhpDebugBar.AjaxHandler` will
+parse the headers and add the dataset to the debugbar.
+
+The AjaxHandler automatically binds to jQuery's *ajaxComplete* event
+so if you are using jQuery, you have nothing to configure.
+
+If you're not using jQuery, you can call `AjaxHandler.handle(xhr)`.
+If you are using the `JavascriptRenderer` initialization, the instance 
+of `AjaxHandler` is stored in the `ajaxHandler` property of the `DebugBar` object.
+
+    debugbar.ajaxHandler.handle(xhr);
+
+## Stacked data
+
+Some times you need to collect data about a request but the page won't actually
+be displayed. The best example of that is during a redirect. You can use the
+debug bar storage mechanism to store the data and re-open it later but it can
+be cumbersome while testing a redirect page.
+
+The solution is to use stacked data. The debug bar can temporarily store the 
+collected data in the session until the next time it will be displayed.
+Simply call `DebugBar::stackData()` instead of rendering the debug bar.
+
+PHP's session must be started before using this feature.
+
+Note: The stacked data feature will use the storage mechanism of it's enabled
+instead of storing the data in the session.
+
+    $debugbar = new DebugBar();
+    // ...
+    $debugbar->stackData();
+
+Stacked data are rendered each time the debug bar is rendered using the
+`JavascriptRenderer`.

docs/manifest.json

@@ -6,7 +6,7 @@
         "../README.md",
         "data_collectors.md",
         "rendering.md",
-        "ajax.md",
+        "ajax_and_stack.md",
         "base_collectors.md",
         "bridge_collectors.md",
         "storage.md",

src/DebugBar/DebugBar.php

@@ -40,6 +40,10 @@ class DebugBar implements ArrayAccess
 
     protected $storage;
 
+    protected $stackSessionNamespace = 'PHPDEBUGBAR_STACK_DATA';
+
+    protected $stackAlwaysUseSessionStorage = false;
+
     /**
      * Adds a data collector
      *
@@ -230,6 +234,120 @@ class DebugBar implements ArrayAccess
         return $this;
     }
 
+    /**
+     * Stacks the data in the session for later rendering
+     */
+    public function stackData()
+    {
+        $this->initStackSession();
+
+        $data = null;
+        if (!$this->isDataPersisted() || $this->stackAlwaysUseSessionStorage) {
+            $data = $this->getData();
+        } else if ($this->data === null) {
+            $this->collect();
+        }
+
+        $_SESSION[$this->stackSessionNamespace][$this->getCurrentRequestId()] = $data;
+        return $this;
+    }
+
+    /**
+     * Checks if there is stacked data in the session
+     * 
+     * @return boolean
+     */
+    public function hasStackedData()
+    {
+        $this->initStackSession();
+        return count($_SESSION[$this->stackSessionNamespace]) > 0;
+    }
+
+    /**
+     * Returns the data stacked in the session
+     * 
+     * @param boolean $delete Whether to delete the data in the session
+     * @return array
+     */
+    public function getStackedData($delete = true)
+    {
+        $this->initStackSession();
+        $stackedData = $_SESSION[$this->stackSessionNamespace];
+        if ($delete) {
+            unset($_SESSION[$this->stackSessionNamespace]);
+        }
+
+        $datasets = array();
+        if ($this->isDataPersisted() && !$this->stackAlwaysUseSessionStorage) {
+            foreach ($stackedData as $id => $data) {
+                $datasets[$id] = $this->getStorage()->get($id);
+            }
+        } else {
+            $datasets = $stackedData;
+        }
+
+        return $datasets;
+    }
+
+    /**
+     * Sets the key to use in the $_SESSION array
+     * 
+     * @param string $ns
+     */
+    public function setStackDataSessionNamespace($ns)
+    {
+        $this->stackSessionNamespace = $ns;
+        return $this;
+    }
+
+    /**
+     * Returns the key used in the $_SESSION array
+     * 
+     * @return string
+     */
+    public function getStackDataSessionNamespace()
+    {
+        return $this->stackSessionNamespace;
+    }
+
+    /**
+     * Sets whether to only use the session to store stacked data even 
+     * if a storage is enabled
+     * 
+     * @param boolean $enabled
+     */
+    public function setStackAlwaysUseSessionStorage($enabled = true)
+    {
+        $this->stackAlwaysUseSessionStorage = $enabled;
+        return $this;
+    }
+
+    /**
+     * Checks if the session is always used to store stacked data
+     * even if a storage is enabled
+     * 
+     * @return boolean
+     */
+    public function isStackAlwaysUseSessionStorage()
+    {
+        return $this->stackAlwaysUseSessionStorage;
+    }
+
+    /**
+     * Initializes the session for stacked data
+     */
+    protected function initStackSession()
+    {
+        if ((function_exists('session_status') && session_status() == PHP_SESSION_NONE) || !isset($_SESSION)) {
+            throw new DebugBarException("Session must be started before using stack data in the debug bar");
+        }
+
+        $ns = $this->stackSessionNamespace;
+        if (!isset($_SESSION[$ns])) {
+            $_SESSION[$ns] = array();
+        }
+    }
+
     /**
      * Returns a JavascriptRenderer for this instance
      * 

src/DebugBar/JavascriptRenderer.php

@@ -614,18 +614,22 @@ class JavascriptRenderer
      * @param boolean $initialize Whether to render the de bug bar initialization code
      * @return string
      */
-    public function render($initialize = true)
+    public function render($initialize = true, $renderStackedData = true)
     {
         $js = '';
 
         if ($initialize) {
             $js = $this->getJsInitializationCode();
         }
+
+        if ($renderStackedData && $this->debugBar->hasStackedData()) {
+            foreach ($this->debugBar->getStackedData() as $id => $data) {
+                $js .= $this->getAddDatasetCode($id, $data);
+            }
+        }
         
-        $js .= sprintf("%s.addDataSet(%s, \"%s\");\n",
-            $this->variableName,
-            json_encode($this->debugBar->getData()),
-            $this->debugBar->getCurrentRequestId());
+        $js .= $this->getAddDatasetCode($this->debugBar->getCurrentRequestId(), $this->debugBar->getData());
+
         return "<script type=\"text/javascript\">\n$js\n</script>\n";
     }
 
@@ -728,4 +732,20 @@ class JavascriptRenderer
 
         return $js;
     }
+
+    /**
+     * Returns the js code needed to add a dataset
+     * 
+     * @param string $requestId
+     * @param array $data
+     * @return string
+     */
+    protected function getAddDatasetCode($requestId, $data)
+    {
+        $js = sprintf("%s.addDataSet(%s, \"%s\");\n",
+            $this->variableName,
+            json_encode($data),
+            $requestId);
+        return $js;
+    }
 }

tests/DebugBar/Tests/DebugBarTest.php

@@ -53,4 +53,38 @@ class DebugBarTest extends DebugBarTestCase
         $data = $this->debugbar->collect();
         $this->assertEquals($s->data[$this->debugbar->getCurrentRequestId()], $data);
     }
+
+    public function testStackedData()
+    {
+        $_SESSION = array();
+        $this->debugbar->addCollector($c = new MockCollector(array('foo')));
+        $this->debugbar->stackData();
+
+        $this->assertArrayHasKey($ns = $this->debugbar->getStackDataSessionNamespace(), $_SESSION);
+        $this->assertArrayHasKey($id = $this->debugbar->getCurrentRequestId(), $_SESSION[$ns]);
+        $this->assertArrayHasKey('mock', $_SESSION[$ns][$id]);
+        $this->assertEquals($c->collect(), $_SESSION[$ns][$id]['mock']);
+        $this->assertTrue($this->debugbar->hasStackedData());
+
+        $data = $this->debugbar->getStackedData();
+        $this->assertArrayNotHasKey($ns, $_SESSION);
+        $this->assertArrayHasKey($id, $data);
+        $this->assertEquals(1, count($data));
+        $this->assertArrayHasKey('mock', $data[$id]);
+        $this->assertEquals($c->collect(), $data[$id]['mock']);
+    }
+
+    public function testStackedDataWithStorage()
+    {
+        $s = new MockStorage();
+        $this->debugbar->setStorage($s);
+        $this->debugbar->addCollector($c = new MockCollector(array('foo')));
+        $this->debugbar->stackData();
+
+        $id = $this->debugbar->getCurrentRequestId();
+        $this->assertNull($_SESSION[$this->debugbar->getStackDataSessionNamespace()][$id]);
+
+        $data = $this->debugbar->getStackedData();
+        $this->assertEquals($c->collect(), $data[$id]['mock']);
+    }
 }