Add the ability to append content to sections.

Closes #135.

docs/templates/sections.md

@@ -7,11 +7,11 @@ title: Sections
 Sections
 ========
 
-The `start()` and `stop()` functions allow you to build sections (or blocks) of content within your template, and instead of them being rendered directly, they are saved for use elsewhere. For example, in your [layout](/templates/layouts/) template.
+The `start()` and `stop` functions allow you to build sections (or blocks) of content within your template, and instead of them being rendered directly, they are saved for use elsewhere. For example, in your [layout](/templates/layouts/) template.
 
 ## Creating sections
 
-You define the name of the section in the `start()` function, and end the section with the `stop()` function.
+You define the name of the section with the `start()` function. To end a section call the `stop()` function.
 
 ~~~ php
 <?php $this->start('welcome') ?>
@@ -22,6 +22,18 @@ You define the name of the section in the `start()` function, and end the sectio
 <?php $this->stop() ?>
 ~~~
 
+## Stacking section content
+
+By default, when you render a section its content will overwrite any existing content for that section. However, it's possible to append (or stack) the content instead using the `push()` method. This can be useful for specifying any JavaScript libraries required by your child views.
+
+~~~ php
+<?php $this->push('scripts') ?>
+    <script src="example.js"></script>
+<?php $this->end() ?>
+~~~
+
+<p class="message-notice">The <code>end()</code> function is simply an alias of <code>stop()</code>. These functions can be used interchangeably.</p>
+
 ## Accessing section content
 
 Access rendered section content using the name you assigned in the `start()` method. This variable can be accessed from the current template and layout templates using the `section()` function.

example/templates/layout.php

@@ -6,5 +6,7 @@
 
 <?=$this->section('content')?>
 
+<?=$this->section('scripts')?>
+
 </body>
 </html>

example/templates/profile.php

@@ -3,4 +3,10 @@
 <h1>User Profile</h1>
 <p>Hello, <?=$this->e($name)?>!</p>
 
-<?php $this->insert('sidebar') ?>
+<?php $this->insert('sidebar') ?>
+
+<?php $this->push('scripts') ?>
+    <script>
+        // Some JavaScript
+    </script>
+<?php $this->end() ?>

src/Template/Template.php

@@ -36,6 +36,18 @@ class Template
      */
     protected $sections = array();
 
+    /**
+     * The name of the section currently being rendered.
+     * @var string
+     */
+    protected $sectionName;
+
+    /**
+     * Whether the section should be appended or not.
+     * @var boolean
+     */
+    protected $appendSection;
+
     /**
      * The name of the template layout.
      * @var string
@@ -178,7 +190,7 @@ public function layout($name, array $data = array())
 
     /**
      * Start a new section block.
-     * @param  string $name
+     * @param  string  $name
      * @return null
      */
     public function start($name)
@@ -189,26 +201,55 @@ public function start($name)
             );
         }
 
-        $this->sections[$name] = '';
+        if ($this->sectionName) {
+            throw new LogicException('You cannot nest sections within other sections.');
+        }
+
+        $this->sectionName = $name;
 
         ob_start();
     }
 
+    /**
+     * Start a new append section block.
+     * @param  string $name
+     * @return null
+     */
+    public function push($name)
+    {
+        $this->appendSection = true;
+
+        $this->start($name);
+    }
+
     /**
      * Stop the current section block.
      * @return null
      */
     public function stop()
     {
-        if (empty($this->sections)) {
+        if (is_null($this->sectionName)) {
             throw new LogicException(
                 'You must start a section before you can stop it.'
             );
         }
 
-        end($this->sections);
+        if (!isset($this->sections[$this->sectionName])) {
+            $this->sections[$this->sectionName] = '';
+        }
+
+        $this->sections[$this->sectionName] = $this->appendSection ? $this->sections[$this->sectionName] . ob_get_clean() : ob_get_clean();
+        $this->sectionName = null;
+        $this->appendSection = false;
+    }
 
-        $this->sections[key($this->sections)] = ob_get_clean();
+    /**
+     * Alias of stop().
+     * @return null
+     */
+    public function end()
+    {
+        $this->stop();
     }
 
     /**

tests/Template/TemplateTest.php

@@ -151,6 +151,21 @@ public function testSection()
         $this->assertEquals($this->template->render(), 'Hello World');
     }
 
+    public function testReplaceSection()
+    {
+        vfsStream::create(
+            array(
+                'template.php' => implode('\n', array(
+                    '<?php $this->layout("layout")?><?php $this->start("test") ?>Hello World<?php $this->stop() ?>',
+                    '<?php $this->layout("layout")?><?php $this->start("test") ?>See this instead!<?php $this->stop() ?>',
+                )),
+                'layout.php' => '<?php echo $this->section("test") ?>',
+            )
+        );
+
+        $this->assertEquals($this->template->render(), 'See this instead!');
+    }
+
     public function testStartSectionWithInvalidName()
     {
         $this->setExpectedException('LogicException', 'The section name "content" is reserved.');
@@ -164,6 +179,19 @@ public function testStartSectionWithInvalidName()
         $this->template->render();
     }
 
+    public function testNestSectionWithinAnotherSection()
+    {
+        $this->setExpectedException('LogicException', 'You cannot nest sections within other sections.');
+
+        vfsStream::create(
+            array(
+                'template.php' => '<?php $this->start("section1") ?><?php $this->start("section2") ?>',
+            )
+        );
+
+        $this->template->render();
+    }
+
     public function testStopSectionBeforeStarting()
     {
         $this->setExpectedException('LogicException', 'You must start a section before you can stop it.');
@@ -198,6 +226,42 @@ public function testNullSection()
         $this->assertEquals($this->template->render(), 'NULL');
     }
 
+    public function testPushSection()
+    {
+        vfsStream::create(
+            array(
+                'template.php' => implode('\n', array(
+                    '<?php $this->layout("layout")?>',
+                    '<?php $this->push("scripts") ?><script src="example1.js"></script><?php $this->end() ?>',
+                    '<?php $this->push("scripts") ?><script src="example2.js"></script><?php $this->end() ?>',
+                )),
+                'layout.php' => '<?php echo $this->section("scripts") ?>',
+            )
+        );
+
+        $this->assertEquals($this->template->render(), '<script src="example1.js"></script><script src="example2.js"></script>');
+    }
+
+    public function testPushWithMultipleSections()
+    {
+        vfsStream::create(
+            array(
+                'template.php' => implode('\n', array(
+                    '<?php $this->layout("layout")?>',
+                    '<?php $this->push("scripts") ?><script src="example1.js"></script><?php $this->end() ?>',
+                    '<?php $this->start("test") ?>test<?php $this->stop() ?>',
+                    '<?php $this->push("scripts") ?><script src="example2.js"></script><?php $this->end() ?>',
+                )),
+                'layout.php' => implode('\n', array(
+                    '<?php echo $this->section("test") ?>',
+                    '<?php echo $this->section("scripts") ?>',
+                )),
+            )
+        );
+
+        $this->assertEquals($this->template->render(), 'test\n<script src="example1.js"></script><script src="example2.js"></script>');
+    }
+
     public function testFetchFunction()
     {
         vfsStream::create(