Make autosubmit work in non-JS enviroments

We require forms to set autosubmit=true on elements which are supposed
to be submitted automatically now. The base form then ensures that this
works in JS environments and non-JS environments as well by applying the
right changes to the HTML.

refs #5525

library/Icinga/Web/Form.php

@@ -8,6 +8,7 @@ use Zend_Form;
 use Zend_View_Interface;
 use Icinga\Application\Icinga;
 use Icinga\Web\Form\Decorator\HelpText;
+use Icinga\Web\Form\Decorator\NoScriptApply;
 use Icinga\Web\Form\Decorator\ElementWrapper;
 use Icinga\Web\Form\Element\CsrfCounterMeasure;
 
@@ -330,6 +331,14 @@ class Form extends Zend_Form
                 $el->removeDecorator('HtmlTag');
                 $el->removeDecorator('Label');
                 $el->removeDecorator('DtDdWrapper');
+
+                if ($el->getAttrib('autosubmit')) {
+                    // Need to add this decorator first or it interferes with the other's two HTML otherwise
+                    $el->addDecorator(new NoScriptApply()); // Non-JS environments
+                    $el->setAttrib('class', 'autosubmit'); // JS environments
+                    unset($el->autosubmit);
+                }
+
                 $el->addDecorator(new ElementWrapper());
                 $el->addDecorator(new HelpText());
             }

library/Icinga/Web/Form/Decorator/NoScriptApply.php

@@ -0,0 +1,35 @@
+<?php
+// {{{ICINGA_LICENSE_HEADER}}}
+// {{{ICINGA_LICENSE_HEADER}}}
+
+namespace Icinga\Web\Form\Decorator;
+
+use Zend_Form_Decorator_Abstract;
+use Icinga\Application\Icinga;
+
+/**
+ * Decorator to add a submit button encapsulated in noscript-tags
+ *
+ * This enables users in non-JS environments to update the contents
+ * of a form without the use of the main submit button.
+ */
+class NoScriptApply extends Zend_Form_Decorator_Abstract
+{
+    /**
+     * Add a submit button encapsulated in noscript-tags to the element
+     *
+     * @param   string      $content    The html rendered so far
+     *
+     * @return  string                  The updated html
+     */
+    public function render($content = '')
+    {
+        if ($content) {
+            $content .= '<noscript><button name="noscript_apply" style="margin-left: 0.5em;" type="submit" value="1">'
+                . Icinga::app()->getViewRenderer()->view->icon('refresh.png') . '&nbsp;' . t('Apply')
+                . '</button></noscript>';
+        }
+
+        return $content;
+    }
+}