Getting Started

Minimal Steps

Installation:

composer require bitverse/identicon-bundle

Enable the bundle in config/bundles.php (Symfony 4+) or app/AppKernel.php (Symfony 2/3):

Bitverse\IdenticonBundle\BitverseIdenticonBundle::class => ['all' => true],

First Use Case: Generate an identicon for a string (e.g., username, email hash) in a controller or service:

use Symfony\Component\HttpFoundation\Response;

class UserController extends AbstractController
{
    public function show(User $user): Response
    {
        $identicon = $this->get('identicon')->getIcon($user->email);
        return new Response($identicon);
    }
}

Where to Look First:
- Configuration: config/packages/bitverse_identicon.yaml (Symfony 4+) or app/config/config.yml (Symfony 2/3).
- Service: The identicon service is auto-registered and ready to use.
- Default Generator: PixelsGenerator (outputs SVG by default; check Generator classes for alternatives).

Implementation Patterns

Core Workflows

Generating Identicons:
- Basic Usage:
```
$identicon = $this->get('identicon')->getIcon('user@example.com');
```
- Custom Preprocessing: Override the default MD5Preprocessor by configuring a custom class in bitverse_identicon.preprocessor.class. Example: Use Bitverse\Identicon\Preprocessor\SHA1Preprocessor for SHA-1 hashing.

Integration with Twig: Pass the identicon service to Twig templates:

{% set identicon = app.service('identicon').getIcon(user.email) %}
<img src="data:image/svg+xml;base64,{{ identicon|base64_encode }}">

Or create a Twig extension for reusable logic.

Dynamic Identicon URLs: Generate URLs for identicons in routes (e.g., /identicon/{hash}):

// routes.yaml
identicon:
    path: /identicon/{hash}
    controller: Bitverse\IdenticonBundle\Controller\IdenticonController::generate

Use this in templates:

<img src="{{ path('identicon', {'hash': user.email}) }}">

Batch Generation: Pre-generate identicons for users and store them in the database (e.g., as identicon_svg column):
```
$user->identicon = $this->get('identicon')->getIcon($user->email);
$user->save();
```

Advanced Patterns

Custom Generators: Extend Bitverse\Identicon\Generator\AbstractGenerator to create new styles (e.g., circular identicons). Configure in bitverse_identicon.generator.class.

Caching: Cache generated identicons to avoid reprocessing:

$cache = $this->get('cache.app');
$cacheKey = 'identicon_' . md5($input);
if (!$cache->has($cacheKey)) {
    $identicon = $this->get('identicon')->getIcon($input);
    $cache->set($cacheKey, $identicon, 3600); // Cache for 1 hour
} else {
    $identicon = $cache->get($cacheKey);
}

Dependency Injection: Inject the identicon service into services/controllers:

# config/services.yaml
App\Service\UserService:
    arguments:
        $identicon: '@identicon'

Gotchas and Tips

Pitfalls

Deprecated Symfony 2/3:
- The package was last updated in 2015 and targets Symfony 2. For Symfony 4/5/6:
  - Use flex recipes or manually configure bundles in config/bundles.php.
  - Replace AppKernel with Kernel and update service registration.
- Workaround: Fork the repo and update dependencies (e.g., symfony/dependency-injection to ^4.0).
Output Format:
- The default PixelsGenerator outputs SVG. If you need PNG/JPEG:
  - Use a library like ImagineBundle to convert SVG to PNG.
  - Or extend AbstractGenerator to implement raster output.
Configuration Overrides:
- Customizing background_color requires hexadecimal values (e.g., #FFFFFF). Invalid values may throw errors.
- Fix: Validate colors in a custom generator or use a preprocessor.
Service Not Found:
- If @identicon fails to resolve, ensure:
  - The bundle is enabled in bundles.php/AppKernel.
  - No typos in the service name (case-sensitive in Symfony 4+).
Performance:
- Generating identicons for large datasets (e.g., 10,000 users) can be slow. Cache aggressively or pre-generate during off-peak hours.

Debugging Tips

Check Generator Output:
- Log the raw output of getIcon() to debug issues:
```
file_put_contents('debug.svg', $this->get('identicon')->getIcon('test'));
```
- Verify the SVG is valid (e.g., open in a browser or validate with W3C SVG Validator).

Preprocessor Debugging:

Override Bitverse\Identicon\Preprocessor\MD5Preprocessor to log input/output:

public function preprocess($input) {
    error_log("Input: $input");
    return parent::preprocess($input);
}

Configuration Errors:
- Symfony 4+ may throw InvalidConfigurationException for malformed YAML. Use:
```
php bin/console debug:config bitverse_identicon
```
  to validate config.

Extension Points

Custom Preprocessors:
- Implement Bitverse\Identicon\Preprocessor\PreprocessorInterface to add logic (e.g., truncate long strings):
```
class TruncatePreprocessor implements PreprocessorInterface {
    public function preprocess($input) {
        return substr($input, 0, 16); // Truncate to 16 chars
    }
}
```
- Configure in bitverse_identicon.preprocessor.class.

Generator Extensions:

Add themes or styles by extending AbstractGenerator. Example:

class CircleGenerator extends AbstractGenerator {
    protected function generatePixels($hash) {
        // Custom logic for circular identicons
    }
}

Set in bitverse_identicon.generator.class.

Event Listeners:

Listen to user creation/updates to auto-generate identicons:

# config/services.yaml
App\EventListener\IdenticonListener:
    tags:
        - { name: kernel.event_listener, event: user.created, method: onUserCreated }

public function onUserCreated(UserCreatedEvent $event) {
    $user = $event->getUser();
    $user->identicon = $this->identicon->getIcon($user->email);
    $user->save();
}

Twig Filters:

Create a Twig filter for one-liners:

// src/Twig/AppExtension.php
public function getFilters() {
    return [
        new TwigFilter('identicon', [$this->identicon, 'getIcon']),
    ];
}

Usage:

<img src="data:image/svg+xml;base64,{{ 'user@example.com'|identicon|base64_encode }}">

Identicon Bundle Laravel Package