Howto do a Captcha in Symfony – with Plugins

There has quite some time passed since i blogged about how to do a captcha with the JpGraph library.
Since then, two new plugins have shown up in order to ease the captcha integration in symfony projects.

The sfCaptchaPlugin uses the JpGraph library while the sfCryptographpPlugin relies on the cryptographp library.
Both plugins have installation instructions in their wiki-pages, but there are small things that might confuse new users, so i decided to write a howto for both of them.

sfCaptchaPlugin

First, install the plugin:

symfony plugin-install http://plugins.symfony-project.com/sfCaptchaPlugin

and enable the module in the settings.yml file (e.g. apps/frontend/config/settings.yml):

all:
  .settings:
    enabled_modules: [default, sfCaptcha]

The sfCaptchaPlugin comes with the digits-only version of the JpGraph library (which is much more readable than the alphanumeric version), but in order to use it you need to open the plugins/sfCaptchaPlugin/lib/Captcha.class.php file and change:

require_once 'jpgraph/jpgraph_antispam.php';

to:

require_once 'jpgraph_antispam-digits.class.php';

Now we need to generate the captcha and save the key in the session. Add the following lines to the function which displays your form:

$g = new Captcha();
$this->getUser()->setAttribute('captcha', $g->generate());

and in the template, add:

<?php use_helper('Validation'); ?>

<img src="<?php echo url_for('sfCaptcha/index'); ?>" alt="captcha" />
<?php echo form_error('captcha'); ?>
<?php echo input_tag('captcha'); ?>

To validate the input, create a validation file in your modules validate folder and add:

fields:
  captcha:
    required:
      msg: Please enter the numbers in the captcha image
    captchaValidator:
      error: Incorrect code

Finally, clear your cache with symfony cc and the captcha should be ready.

sfCryptographpPlugin

Install the plugin with:

symfony plugin-install http://plugins.symfony-project.com/sfCryptographpPlugin

and enable the module in the settings.yml file (e.g. apps/frontend/config/settings.yml):

all:
  .settings:
    enabled_modules: [default, cryptographp]

Open the template file which contains your form, and add:

<?php use_helper('Cryptographp', 'Validation'); ?>

<?php echo cryptographp_picture(); ?>
<?php echo cryptographp_reload(); ?>

<?php echo form_error('captcha'); ?>
<?php echo input_tag('captcha'); ?>

To validate the input, create a validation file in your modules validate folder and add:

fields:
  captcha:
    required:
      msg: security code required
    sfCryptographpValidator:
      code_error: security code incorrect

Finally, clear your cache with symfony cc and you should be ready to go.

Unlike JpGraph, the cryptohraphp lib comes with a variety of config options, you can take a look at the documentation and the plugins/sfCryptographpPlugin/lib/crypt/config.inc.php file.
For example, if you want to modify the width of the captcha image, open your applications app.yml file and add:

all:
  cryptographp:
    width: 300