Fatal error: Using $this when not in object context in D:\myWebSite\plugins\sfCaptchaGDPlugin\config\config.php on line 5

$this->dispatcher->connect('routing.load_configuration', array('sfCaptchaGDRouting', 'listenToRoutingLoadConfigurationEvent'));

  sfCaptchaGDPlugin:
    routes_register:  false

sf_captchagd:
  url:    /captcha
  param:  { module: sfCaptchaGD, action: GetImage }

//    if ($context->getRequest()->getGetParameter('reload') || ! $securityCode){
    if ($context->getRequest()->getParameter('reload') || ! $securityCode){

sf_captchagd:
  url:    /captcha/:key/:reload
  param:  { module: sfCaptchaGD, action: getImage, key: failed, reload: 0 }

      <?php echo input_tag('captcha', null) ?>
      <?php echo link_to_function(image_tag(url_for('@sf_captchagd?key='.time()), array('id'=>'captcha_img', 'alt'=>'Click if you cannot read the picture')),
                                    'document.getElementById(\'captcha_img\').src=\''.
                                    url_for('@sf_captchagd?reload=1').
                                    '&key=\'+Math.round(Math.random(0)*1000)+1+\'\'') ?>

In your second post at bullet #2 I put the code in the routing.yml, not the settings.yml because it seemed more appropriate.

I managed to get through the errors, but I get no image.

Note: Also, I had to include the Javascript helper in my template first in order to get it working. link_to_function() is part of the Javascript helper.

I'm using Firefox 3 on Ubuntu 8.04, but I think that not the browser is the main problem.

And yes, I see the alt link, but nothing happens when I click on it.

$context->getResponse()->send();

$context->getResponse()->sendContent();

Warning: Cannot modify header information - headers already sent by (output started at /home/boteeka/Work/rmcssz/plugins/sfCaptchaGDPlugin/lib/sfCaptchaGD.class.php:123) in /usr/share/php/symfony/response/sfWebResponse.class.php on line 264

Warning: Cannot modify header information - headers already sent by (output started at /home/boteeka/Work/rmcssz/plugins/sfCaptchaGDPlugin/lib/sfCaptchaGD.class.php:123) in /usr/share/php/symfony/response/sfWebResponse.class.php on line 274

    // create a new string with a blank space between each letter so it looks better
    $newstr = "";
    for ($i = 0; $i < strlen($this->securityCode); $i++) {
        $newstr .= $this->securityCode[$i] ." ";
    }

    // create a new string with a blank space between each letter so it looks better
    $newstr = "";
    $splittedString = str_split($this->securityCode);
    for ($i = 0; $i < strlen($this->securityCode); $i++) {
        $newstr .= $splittedString[$i] ." ";
    }

.
  protected function getFonts(){
  	if (is_dir($this->fonts_dir)){
  		$files = sfFinder::type('file')->ignore_version_control(true)->name('*.ttf')->relative()->maxdepth(3)->in($this->fonts_dir);
  		foreach($files as $file){
  			$this->fonts[]=$file;
  		}
  	}
  }

  function __construct() {
      $this->border_color = sfConfig::get('app_sf_captchagd_border_color', "000000");
      $this->background_color = sfConfig::get('app_sf_captchagd_background_color', "DDDDDD");
      $this->fonts_dir = sfConfig::get('app_sf_captchagd_fonts_dir', sfConfig::get('sf_plugins_dir').'/sfCaptchaGDPlugin/data/fonts/');
      $this->fontSize = sfConfig::get('app_sf_captchagd_font_size', "18");
      $this->fontColor = sfConfig::get('app_sf_captchagd_font_color', array("252525", "8b8787", "550707", "3526E6", "88531E"));
      $this->chars = sfConfig::get('app_sf_captchagd_chars', "123456789");
      $this->codeLength = sfConfig::get('app_sf_captchagd_length', 4);
      $this->image_width = sfConfig::get('app_sf_captchagd_image_width', 100);
      $this->image_height = sfConfig::get('app_sf_captchagd_image_height', 30);

      $this->getFonts();
  }

sf_captchagd:
  url:    /captcha/:key/:reload
  param:  { module: sfCaptchaGD, action: getImage, key: failed, reload: 0 }

 <a href='' onClick='return false' title='Reload image'><img id='captchaimg' src='<?php echo url_for('@sf_captchagd?key='.gmdate('Y-m-d h:m:s'))?>' onClick="<?php echo 'document.getElementById(\'captchaimg\').src=\''.url_for('@sf_captchagd?reload=1').'&key=\'+Math.round(Math.random(0)*1000)+1+\'\''?>" border='0'></a>

if ($context->getRequest()->getGetParameter('reload') || ! $securityCode){
   $this->securityCode = $this->simpleRandString($this->codeLength, $this->chars);
} else {
   $this->securityCode = $securityCode;
}

//if ($context->getRequest()->getGetParameter('reload') || ! $securityCode){
   $this->securityCode = $this->simpleRandString($this->codeLength, $this->chars);  // Just use this line
//} else {
//   $this->securityCode = $securityCode;
//}

GetImage:
  is_secure:   off

class BaseSzkolaForm extends BaseFormPropel
{
  public function setup()
  {
    $this->setWidgets(array(
      ...
	  'captcha'  => new sfWidgetCaptchaGD(),
    ));

    $this->setValidators(array(
      ...
    'captcha'  => new sfCaptchaGDValidator(array('length' => 4)),
    ));

    ...
  }
...
}

sf_captchagd:
  url:    /captcha/:key/:reload
  param:  { module: sfCaptchaGD, action: getImage, key: failed, reload: 0 }

protected function processForm(sfWebRequest $request, sfForm $form)
{
  $form->bind(array(
     'captcha' => $request->getParameter('captcha'),
     $request->getParameter($form->getName())),
     $request->getFiles($form->getName())
     );
    if ($form->isValid())
    {
      ...
    }
  }

<a href="../apps/frontend:/captcha?1">

// lib\form\ContactForm.class.php
class ContactForm extends sfForm
{
  public function configure()
  {
    $this->setWidgets(array(
      'name'    => new sfWidgetFormInput(),
      'email'   => new sfWidgetFormInput(),
      'message' => new sfWidgetFormTextarea(),
      'captcha' => new sfWidgetCaptchaGD(),
    ));

    $this->setValidators(array(
      'name'    => new sfValidatorString(array('required' => false)),
      'email'   => new sfValidatorEmail(),
      'message' => new sfValidatorString(array('min_length' => 4)),
      'captcha' => new sfCaptchaGDValidator(array('length' => 4)),
    ));
  }
}

// apps\...\action.class.php
class captchagdActions extends sfActions
{
  public function executeIndex(sfWebRequest $request)
  {
    $this->form = new ContactForm();

    if ($request->isMethod('post'))
    {
      $this->form->bind(array(
        'name'      => $request->getParameter('name'), 
        'email'     => $request->getParameter('email'),
        'message'   => $request->getParameter('message'),
        'captcha'   => $request->getParameter('captcha'),
      ));
      if ($this->form->isValid()){
        $this->msg = "OK!";
      } else {
        $this->msg = "ERR!";
      }
    }
  }
}

// apps\...\indexSuccess.php
<?php
  if (isset($msg))
  {
	echo "<h3>$msg</h3>";
  }
?>
<form method="POST">
  <table>
    <?php echo $form ?>
    <tr>
      <td colspan="2">
        <input type="submit" />
      </td>
    </tr>
  </table>
</form>

//lib\form\base\BaseSzkolaForm.class.php
class BaseSzkolaForm extends BaseFormPropel
{
  public function setup()
  {
    $this->setWidgets(array(
      'id'               => new sfWidgetFormInputHidden(),

      .
      .
      .

      'captcha' 		 => new sfWidgetCaptchaGD(),
    ));

    $this->setValidators(array(
      'id'         => new sfValidatorPropelChoice(array('model' => 'Szkola', 'column' => 'id', 'required' => false)),
      'captcha' 		 => new sfCaptchaGDValidator(array('length' => 4)),
    ));

    $this->widgetSchema->setNameFormat('szkola[%s]');

    $this->errorSchema = new sfValidatorErrorSchema($this->validatorSchema);

    parent::setup();
  }

//...\actions.class.php
...
$form->bind($request->getParameter($form->getName()), $request->getFiles($form->getName()));
...

$this->form->bind(array(
        'name'      => $request->getParameter('name'), 
        'email'     => $request->getParameter('email'),
        'message'   => $request->getParameter('message'),
        'captcha'   => $request->getParameter('captcha'),
      ));

$this->form->bind(array(
        'name'      => $request->getParameter('name'), 
        'email'     => $request->getParameter('email'),
        'message'   => $request->getParameter('message'),
        'captcha'   => $request->getParameter('captcha'),
        '_csrf_token'   => $request->getParameter('_csrf_token'),
      ));

var_dump($request->getParameter($this->form->getName())); 
die();