### Initialize and Check Throttler

Source: https://github.com/codeigniter4/userguide/blob/master/docs/libraries/throttler.html

Demonstrates how to get an instance of the Throttler service and perform a check. This example sets up a bucket allowing 60 actions per minute, effectively one action per second.

```php
<?php

$throttler = service('throttler');
$throttler->check($name, 60, MINUTE);
```

--------------------------------

### Hello World Controller Example (Legacy Auto-Routing)

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/controllers.html

A basic 'Hello World' controller that works with CodeIgniter's legacy auto-routing. Ensure the controller file name and class name start with an uppercase letter.

```php
<?php

namespace App\Controllers;

class Helloworld extends BaseController
{
    public function index()
    {
        return 'Hello World!';
    }
}
```

--------------------------------

### CI3 Site Configuration Example

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/upgrade_configuration.html

Example of a configuration file in CodeIgniter 3.

```php
<?php

defined('BASEPATH') OR exit('No direct script access allowed');

$siteName  = 'My Great Site';
$siteEmail = 'webmaster@example.com';
```

--------------------------------

### Controller Example for Passing Data

Source: https://github.com/codeigniter4/userguide/blob/master/docs/outgoing/views.html

An example controller method that prepares data and passes it to the 'blog_view'.

```php
<?php

namespace App\Controllers;

class Blog extends BaseController
{
    public function index()
    {
        $data['title']   = 'My Real Title';
        $data['heading'] = 'My Real Heading';

        return view('blog_view', $data);
    }
}
```

--------------------------------

### Start a Timer

Source: https://github.com/codeigniter4/userguide/blob/master/docs/testing/benchmark.html

Use the `start()` method to begin timing a specific operation. Provide a unique string name to identify this timer later.

```php
$benchmark = service('timer');
$benchmark->start('render view');
```

--------------------------------

### Publish Remote URI Example

Source: https://github.com/codeigniter4/userguide/blob/master/docs/libraries/publisher.html

This example shows how to download a remote resource using `addUri()` and publish it to your project, enabling overwrites with `true`.

```php
<?php

$publisher->addUri('https://example.com/feeds/daily_photo.jpg')->copy(true);
```

--------------------------------

### Example Route Output (Legacy)

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/routing.html

An example of the output from the 'php spark routes' command, showing route details.

```text
+---------+---------+---------------+-------------------------------+----------------+---------------+
| Method  | Route   | Name          | Handler                       | Before Filters | After Filters |
+---------+---------+---------------+-------------------------------+----------------+---------------+
| GET     | /       | »             | \App\Controllers\Home::index  |                | toolbar       |
| GET     | feed    | »             | (Closure)                     |                | toolbar       |
+---------+---------+---------------+-------------------------------+----------------+---------------+
```

--------------------------------

### Example Spark Command

Source: https://github.com/codeigniter4/userguide/blob/master/docs/cli/cli_commands.html

A basic example of a Spark command class. This command can be executed from the CLI.

```php
<?php

namespace App\Commands;

use CodeIgniter\CLI\BaseCommand;

class Hello extends BaseCommand
{
    protected $group = 'Misc';
    protected $name = 'hello';
    protected $description = 'Says hello.';
    protected $usage = 'hello [name]';
    protected $arguments = [
        'name' => 'The name to greet.'
    ];

    public function run(array $params)
    {
        $name = $params['name'] ?? 'World';

        // Output a message to the console
        $this->line("Hello, {$name}!");
    }
}
```

--------------------------------

### AuthPublish Command Example

Source: https://github.com/codeigniter4/userguide/blob/master/docs/libraries/publisher.html

Example of a custom CLI command to publish authentication module components.

```APIDOC
## `auth:publish` Command

### Description

This command allows users to publish the authentication module's components (Controllers, Migrations, Models) into their application.

### Usage

```bash
php spark auth:publish
```

### Example Implementation

```php
<?php

namespace Math\Auth\Commands;

use CodeIgniter\CLI\BaseCommand;
use CodeIgniter\Publisher\Publisher;
use Throwable;

class AuthPublish extends BaseCommand
{
    protected $group       = 'Auth';
    protected $name        = 'auth:publish';
    protected $description = 'Publish Auth components into the current application.';

    public function run(array $params)
    {
        // Use the Autoloader to figure out the module path
        $source = service('autoloader')->getNamespace('Math\\Auth')[0];

        $publisher = new Publisher($source, APPPATH);

        try {
            // Add only the desired components
            $publisher->addPaths([
                'Controllers',
                'Database/Migrations',
                'Models',
            ])->merge(false); // Be careful not to overwrite anything
        } catch (Throwable $e) {
            $this->showError($e);

            return;
        }

        // If publication succeeded then update namespaces
        foreach ($publisher->getPublished() as $file) {
            // Replace the namespace
            $contents = file_get_contents($file);
            $contents = str_replace('namespace Math\\Auth', 'namespace ' . APP_NAMESPACE, $contents);
            file_put_contents($file, $contents);
        }
    }
}
```
```

--------------------------------

### Example Language File Content

Source: https://github.com/codeigniter4/userguide/blob/master/docs/outgoing/localization.html

An example of a language file containing both simple and nested language strings.

```php
<?php

return [
    'errorEmailMissing'    => 'You must submit an email address',
    'errorURLMissing'      => 'You must submit a URL',
    'errorUsernameMissing' 	=> 'You must submit a username',
    'nested'               	=> [
        'error' 	=> [
            'message' 	=> 'A specific error message',
        ],
    ],
];
```

--------------------------------

### Basic Feature Test Class Setup

Source: https://github.com/codeigniter4/userguide/blob/master/docs/testing/feature.html

Sets up a feature test class by using DatabaseTestTrait and FeatureTestTrait. Ensure parent setUp() and tearDown() are called if overridden.

```PHP
<?php

namespace Tests\Feature;

use CodeIgniter\Test\CIUnitTestCase;
use CodeIgniter\Test\DatabaseTestTrait;
use CodeIgniter\Test\FeatureTestTrait;

class FooTest extends CIUnitTestCase
{
    use DatabaseTestTrait;
    use FeatureTestTrait;

    protected function setUp(): void
    {
        parent::setUp();

        $this->myClassMethod();
    }

    protected function tearDown(): void
    {
        parent::tearDown();

        $this->anotherClassMethod();
    }
}
```

--------------------------------

### Equivalent Fabricator Setup for Test Helper

Source: https://github.com/codeigniter4/userguide/blob/master/docs/testing/fabricator.html

This demonstrates the equivalent setup using the `Fabricator` class directly, which is what the `fake()` helper function abstracts.

```php
use CodeIgniter\Test\Fabricator;

$fabricator = new Fabricator('App\Models\UserModel');
$fabricator->setOverrides(['name' => 'Gerry']);
$user = $fabricator->create();
```

--------------------------------

### Retrieve Limited Records with get()

Source: https://github.com/codeigniter4/userguide/blob/master/docs/database/query_builder.html

The get() method accepts limit and offset parameters to control the number of records returned and their starting position.

```php
<?php

$query = $builder->get(10, 20);
/*
 * Executes: SELECT * FROM mytable LIMIT 20, 10
 * (in MySQL. Other databases have slightly different syntax)
 */
```

--------------------------------

### CodeIgniter 3 Database Query Example

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/upgrade_database.html

Example of a database query using CodeIgniter 3 syntax, demonstrating select, where, limit, and get methods.

```php
$query = $this->db->select('title')
             ->where('id', $id)
             ->limit(10, 20)
             ->get('mytable');
```

--------------------------------

### Configure Database Connection

Source: https://github.com/codeigniter4/userguide/blob/master/docs/guides/first-app/news_section.html

Example database configuration settings for the .env file. Ensure these match your local database credentials.

```properties
database.default.hostname = localhost
database.default.database = ci4tutorial
database.default.username = root
database.default.password = root
database.default.DBDriver = MySQLi
```

--------------------------------

### Instantiate Configuration Object with `new`

Source: https://github.com/codeigniter4/userguide/blob/master/docs/general/configuration.html

Use the `new` keyword to manually create an instance of a configuration class.

```php
<?php

// Creating new configuration object by hand
$config \= new \Config\Pager();
```

--------------------------------

### Get Query Execution Start Time

Source: https://github.com/codeigniter4/userguide/blob/master/docs/database/queries.html

Retrieve the timestamp, including microseconds, when the query execution began.

```php
<?php

$microtime = $query->getStartTime();
```

--------------------------------

### CodeIgniter 3 Migration Example

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/upgrade_migrations.html

This is an example of a CodeIgniter 3 migration file for creating a 'blog' table. It uses sequential naming and the older CI_Migration class structure.

```php
<?php

defined('BASEPATH') OR exit('No direct script access allowed');

class Migration_Add_blog extends CI_Migration
{
    public function up()
    {
        $this->dbforge->add_field(array(
            'blog_id' => array(
                'type'           => 'INT',
                'constraint'     => 5,
                'unsigned'       => true,
                'auto_increment' => true,
            ),
            'blog_title' => array(
                'type'       => 'VARCHAR',
                'constraint' => '100',
            ),
            'blog_description' => array(
                'type' => 'TEXT',
                'null' => true,
            ),
        ));
        $this->dbforge->add_key('blog_id', true);
        $this->dbforge->create_table('blog');
    }

    public function down()
    {
        $this->dbforge->drop_table('blog');
    }
}
```

--------------------------------

### Example `config:check` Output

Source: https://github.com/codeigniter4/userguide/blob/master/docs/general/configuration.html

This output shows the structure and current values of the `Config\App` instance, including properties, their types, and values. It also indicates whether Config Caching is enabled.

```text
Config\App#6 (
    public 'baseURL' => string (22) "http://localhost:8080/"
    public 'allowedHostnames' => array (0) []
    public 'indexPage' => string (9) "index.php"
    public 'uriProtocol' => string (11) "REQUEST_URI"
    public 'defaultLocale' => string (2) "en"
    public 'negotiateLocale' => boolean false
    public 'supportedLocales' => array (1) [
        0 => string (2) "en"
    ]
    public 'appTimezone' => string (3) "UTC"
    public 'charset' => string (5) "UTF-8"
    public 'forceGlobalSecureRequests' => boolean false
    public 'proxyIPs' => array (0) []
    public 'CSPEnabled' => boolean false
)

Config Caching: Disabled
```

--------------------------------

### CodeIgniter 3 Controller

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/upgrade_validations.html

Example controller in CodeIgniter 3 demonstrating form validation setup and execution.

```php
<?php

class Form extends CI_Controller {

    public function index()
    {
        $this->load->helper(array('form', 'url'));

        $this->load->library('form_validation');

        // Set validation rules

        if ($this->form_validation->run() == FALSE) {
                $this->load->view('myform');
        } else {
                $this->load->view('formsuccess');
        }
    }
}

```

--------------------------------

### Defining a Route for a Controller Method

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/controllers.html

Example of manually defining a GET route for the 'index' method of the 'HelloWorld' controller using PSR-4 Autoloader conventions.

```php
<?php

/*
 * Folder and file structure:
 * \<NamespaceName>(\<SubNamespaceNames>)*\<ClassName>
 */

$routes->get('helloworld', '\App\Controllers\HelloWorld::index');

```

--------------------------------

### Get URI Segment by Index

Source: https://github.com/codeigniter4/userguide/blob/master/docs/libraries/uri.html

Shows how to access specific segments of a URI path, starting from index 1. It also illustrates conditional segment retrieval.

```php
<?php

// URI = http://example.com/users/15/profile

// Prints '15'
if ($uri\->getSegment(1) \=== 'users') {
    echo $uri\->getSegment(2);
}
```

--------------------------------

### Instantiate Configuration File

Source: https://github.com/codeigniter4/userguide/blob/master/docs/general/modules.html

Create a new instance of a configuration file using its fully qualified class name.

```php
$config = new \Acme\Blog\Config\Blog();
```

--------------------------------

### Install CodeIgniter 4 Project

Source: https://github.com/codeigniter4/userguide/blob/master/docs/guides/api/index.html

Use Composer to create a new CodeIgniter 4 project for your API. Navigate into the project directory and start the development server.

```bash
composer create-project codeigniter4/appstarter books-api
cd books-api
php spark serve
```

--------------------------------

### Create a Custom Cast Handler

Source: https://github.com/codeigniter4/userguide/blob/master/docs/models/entities.html

Define a custom cast handler class that extends CodeIgniter\Entity\Cast\BaseCast. This example shows a Base64 encoder/decoder. Implement get() for retrieving and set() for storing data.

```php
<?php

namespace App\Entities\Cast;

use CodeIgniter\Entity\Cast\BaseCast;

// The class must inherit the CodeIgniter\Entity\Cast\BaseCast class
class CastBase64 extends BaseCast
{
    public static function get($value, array $params = [])
    {
        return base64_decode($value, true);
    }

    public static function set($value, array $params = [])
    {
        return base64_encode($value);
    }
}

```

--------------------------------

### Example CLI Command: AppInfo

Source: https://github.com/codeigniter4/userguide/blob/master/docs/cli/cli_commands.html

This example command displays basic application information like PHP version, CodeIgniter version, and system paths using the CLI library for colored output.

```php
namespace App\Commands;

use CodeIgniter\CLI\BaseCommand;
use CodeIgniter\CLI\CLI;

class AppInfo extends BaseCommand
{
    protected $group       = 'Demo';
    protected $name        = 'app:info';
    protected $description = 'Displays basic application information.';

    public function run(array $params)
    {
        CLI::write('PHP Version: ' . CLI::color(PHP_VERSION, 'yellow'));
        CLI::write('CI Version: ' . CLI::color(\CodeIgniter\CodeIgniter::CI_VERSION, 'yellow'));
        CLI::write('APPPATH: ' . CLI::color(APPPATH, 'yellow'));
        CLI::write('SYSTEMPATH: ' . CLI::color(SYSTEMPATH, 'yellow'));
        CLI::write('ROOTPATH: ' . CLI::color(ROOTPATH, 'yellow'));
        CLI::write('Included files: ' . CLI::color(count(get_included_files()), 'yellow'));
    }
}
```

--------------------------------

### Showing Help

Source: https://github.com/codeigniter4/userguide/blob/master/docs/cli/cli_commands.html

The `showHelp()` method displays detailed help information for a command, including its usage, arguments, description, and options.

```APIDOC
## showHelp()

### Description
A method to show command help (usage, arguments, description, options).
```

--------------------------------

### Initialize and Add Files to FileCollection

Source: https://github.com/codeigniter4/userguide/blob/master/docs/libraries/file_collections.html

Demonstrates initializing a FileCollection with an array of files and adding files from a directory recursively.

```php
use CodeIgniter\Files\FileCollection;

$files = new FileCollection([
    FCPATH . 'index.php',
    ROOTPATH . 'spark',
]);
$files->addDirectory(APPPATH . 'Filters');
```

--------------------------------

### Map HTTP Verbs to Controller Methods

Source: https://github.com/codeigniter4/userguide/blob/master/docs/guides/api/first-endpoint.html

Illustrates how different HTTP verbs map to specific controller method names when using auto-routing. For example, GET requests map to getIndex(), POST to postIndex(), and DELETE to deleteIndex().

```plaintext
HTTP Verb

Method Name

`GET /api/ping` `POST /api/ping` `DELETE /api/ping`

`getIndex()` `postIndex()` `deleteIndex()`
```

--------------------------------

### Retrieve Combined GET and POST Streams

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Retrieve all combined GET and POST data. GET data is preferred in case of name conflicts.

```php
$request->getGetPost();
```

--------------------------------

### Load a Library using Factories

Source: https://github.com/codeigniter4/userguide/blob/master/docs/concepts/factories.html

Example of loading a library using the Factories::library() method after configuring a custom path.

```php
use CodeIgniter\Config\Factories;

$someLib = Factories::library('SomeLib');
```

--------------------------------

### Retrieve Combined GET and POST Parameter

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Retrieve a specific parameter from both GET and POST streams, prioritizing GET data. Filtering can be applied.

```php
$request->getGetPost('field1');
```

```php
$request->getGetPost('field1', FILTER_SANITIZE_FULL_SPECIAL_CHARS);
```

--------------------------------

### Create and Reconfigure Encryption Instance

Source: https://github.com/codeigniter4/userguide/blob/master/docs/libraries/encryption.html

Demonstrates how to create a new Encryption instance and reconfigure it with custom settings using a configuration object.

```php
<?php

// create an Encryption instance
$encryption \= new \CodeIgniter\Encryption\Encryption();

// reconfigure an instance with different settings
$encrypter \= $encryption\->initialize($config);

```

```php
<?php

$encrypter \= $encryption\->initialize(\[\'cipher\' \=> \'AES-256-CTR\'\], \$config);

```

--------------------------------

### Initialize Database Class

Source: https://github.com/codeigniter4/userguide/blob/master/docs/database/examples.html

Shows how to initialize the database class. Ensure your database configuration is set up correctly in app/Config/Database.php.

```php
$db = 
	database_connect();

// Or if you have multiple connections defined
$db = 
	database_connect('group_one');
```

--------------------------------

### Start and Stop Timer with Global Function

Source: https://github.com/codeigniter4/userguide/blob/master/docs/testing/benchmark.html

The global `timer()` function provides a shorthand for starting and stopping timers. Call it once to start and again with the same name to stop.

```php
// Start the timer
timer('render view');
// Stop a running timer,
// if one of this name has been started
timer('render view');
```

--------------------------------

### Get Records using Query Builder

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/upgrade_database.html

Replaces the CI3 `$this->db->get()` method when used with the Query Builder. The `get()` method is now called on the builder instance.

```php
$builder->get();
```

--------------------------------

### Initialize Session with ArrayHandler for Testing

Source: https://github.com/codeigniter4/userguide/blob/master/docs/testing/session_testing.html

Demonstrates how to create a session instance using the ArrayHandler driver, suitable for testing environments. Requires loading session configuration.

```php
<?php

use CodeIgniter\Session\Handlers\ArrayHandler;
use CodeIgniter\Session\Session;
use Config\Session as SessionConfig;

// Load session config
$config = config(SessionConfig::class);

// Initialize ArrayHandler with config and optional IP
$arrayHandler = new ArrayHandler($config, '127.0.0.1');

// Create session instance for testing
$testSession = new Session($arrayHandler, $config);
```

--------------------------------

### Getting GET Data

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Retrieves data from the `$_GET` superglobal array.

```APIDOC
## getGet()

### Description
Retrieves data from the `$_GET` superglobal array.

### Method
`getGet()`

### Endpoint
N/A (Method of a Request object)

### Parameters
None

### Request Example
```php
$request->getGet()
```

### Response
Returns an array of GET data.
```

--------------------------------

### Getting GET then POST Data

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Checks `$_GET` first, then `$_POST` for data.

```APIDOC
## getGetPost()

### Description
Checks `$_GET` first, then `$_POST` for data.

### Method
`getGetPost()`

### Endpoint
N/A (Method of a Request object)

### Parameters
None

### Request Example
```php
$request->getGetPost()
```

### Response
Returns data found first in `$_GET`, then `$_POST`.
```

--------------------------------

### Method Chaining Example

Source: https://github.com/codeigniter4/userguide/blob/master/docs/database/query_builder.html

Demonstrates how to chain multiple query builder methods together for a concise query construction.

```php
<?php

$query = $builder->select('title')
    ->where('id', $id)
    ->limit(10, 20)
    ->get();
```

--------------------------------

### Getting POST then GET Data

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Checks `$_POST` first, then `$_GET` for data.

```APIDOC
## getPostGet()

### Description
Checks `$_POST` first, then `$_GET` for data.

### Method
`getPostGet()`

### Endpoint
N/A (Method of a Request object)

### Parameters
None

### Request Example
```php
$request->getPostGet()
```

### Response
Returns data found first in `$_POST`, then `$_GET`.
```

--------------------------------

### CodeIgniter 3 Model Example

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/upgrade_models.html

This is an example of a model file in CodeIgniter 3.

```php
<?php

class News_model extends CI_Model
{
    public function set_news($title, $slug, $text)
    {
        $data = array(
            'title' => $title,
            'slug'  => $slug,
            'text'  => $text,
        );

        return $this->db->insert('news', $data);
    }
}
```

--------------------------------

### Initialize Session using Helper

Source: https://github.com/codeigniter4/userguide/blob/master/docs/libraries/sessions.html

The session() helper function provides a friendlier way to access the default session configuration without passing any options.

```php
<?php

$session = session();

```

--------------------------------

### Retrieve GET Data with Filtering

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Fetch specific GET parameters using getGet(), optionally applying PHP filters for sanitization. Call without parameters to retrieve all GET items as an array.

```php
<?php

$request->getGet('some_data');
```

```php
<?php

$request->getGet('some_data', FILTER_SANITIZE_FULL_SPECIAL_CHARS);
```

--------------------------------

### Initializing a Model

Source: https://github.com/codeigniter4/userguide/blob/master/docs/models/model.html

Demonstrates extending the `initialize()` method to perform additional setup after the model's constructor. This is useful for appending custom fields or other configurations.

```php
<?php

namespace App\Models;

use Modules\Authentication\Models\UserAuthModel;

class UserModel extends UserAuthModel
{
    // ...

    /**
     * Called during initialization. Appends
     * our custom field to the module's model.
     */
    protected function initialize()
    {
        $this->allowedFields[] = 'middlename';
    }
}
```

--------------------------------

### Initialize Session using Service

Source: https://github.com/codeigniter4/userguide/blob/master/docs/libraries/sessions.html

Use the service() method to get an instance of the Session class, optionally passing configuration. The default configuration is used if no config is provided.

```php
<?php

$session = service('session', $config);

```

--------------------------------

### getGet()

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Retrieves a variable from the GET superglobal, with optional filtering. Can retrieve all GET items if no index is provided.

```APIDOC
## getGet($index = null, $filter = null, $flags = null)

Parameters:

* **$index** (`string`) – The name of the variable/key to look for.
* **$filter** (`int`) – The type of filter to apply. A list of filters can be found in [Types of filters](https://www.php.net/manual/en/filters.php).
* **$flags** (`int`) – Flags to apply. A list of flags can be found in [Filter flags](https://www.php.net/manual/en/filter.constants.php#filter.constants.flags.generic).

Returns:

`$_GET` if no parameters supplied, otherwise the GET value if found, or null if not

Return type:

`array|bool|float|int|object|string|null`

The first parameter will contain the name of the GET item you are looking for:

```php
$request->getGet('some_data');
```

The method returns null if the item you are attempting to retrieve does not exist.

The second optional parameter lets you run the data through the PHP’s filters. Pass in the desired filter type as the second parameter:

```php
$request->getGet('some_data', FILTER_SANITIZE_FULL_SPECIAL_CHARS);
```

To return an array of all GET items call without any parameters.
```

--------------------------------

### Instantiate Library

Source: https://github.com/codeigniter4/userguide/blob/master/docs/general/modules.html

Create a new instance of a library using its fully qualified class name.

```php
$lib = new \Acme\Blog\Libraries\BlogLib();
```

--------------------------------

### Start Local Development Server on Custom Host

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/running.html

Specify a custom host for the local development server using the --host CLI option. This is useful for running multiple sites or testing specific domain configurations.

```bash
php spark serve --host example.dev
```

--------------------------------

### CodeIgniter 4.x Image Manipulation Example

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/upgrade_images.html

Example of using the Image Manipulation Class in CodeIgniter 4.x.

```php
$image = service('image');

$image->withFile('/path/to/image.jpg')
      ->thumbnail(['width' => 75, 'height' => 50])
      ->save('/path/to/new_image.jpg');
```

--------------------------------

### initialize()

Source: https://github.com/codeigniter4/userguide/blob/master/docs/genindex.html

Initializes the encryption library.

```APIDOC
## initialize()

### Description
Initializes the encryption library.

### Method
(Not specified in source)

### Endpoint
(Not specified in source)

### Parameters
(Not specified in source)

### Request Example
(Not specified in source)

### Response
(Not specified in source)
```

--------------------------------

### Plugin with Key/Value Parameters

Source: https://github.com/codeigniter4/userguide/blob/master/docs/outgoing/view_parser.html

Illustrates how to pass parameters to a plugin using key/value pairs. Values with spaces should be quoted.

```html
{+ foo bar=2 baz="x y" +}
```

--------------------------------

### CodeIgniter 3.x Image Manipulation Example

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/upgrade_images.html

Example of using the Image Manipulation Class in CodeIgniter 3.x.

```php
$this->load->library('image_lib');

$config['image_library'] = 'gd2';
$config['source_image'] = '/path/to/image.jpg';
$config['create_thumb'] = TRUE;
$config['new_image'] = '/path/to/new_image.jpg';
$config['maintain_ratio'] = TRUE;
$config['width'] = 75;
$config['height'] = 50;

$this->image_lib->initialize($config);

if (!$this->image_lib->resize()) {
    echo $this->image_lib->display_error();
}
```

--------------------------------

### Get and Set URI Host

Source: https://github.com/codeigniter4/userguide/blob/master/docs/libraries/uri.html

Demonstrates how to retrieve the host from a URI object and how to set a new host.

```php
<?php

$uri \= new \CodeIgniter\HTTP\URI('http://www.example.com/some/path');

echo $uri\->getHost();   // www.example.com
echo $uri\->setHost('anotherexample.com')\->getHost();    // anotherexample.com
```

--------------------------------

### Distinguishing Resource and Presenter Routes

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/restful.html

Example showing how to define distinct routes for resource and presenter controllers to avoid conflicts.

```php
<?php

$routes->resource('api/photo');
$routes->presenter('admin/photos');
```

--------------------------------

### Install PHPUnit with Composer

Source: https://github.com/codeigniter4/userguide/blob/master/docs/testing/overview.html

Use Composer to add PHPUnit as a development dependency to your project. This is the recommended installation method.

```bash
composer require --dev phpunit/phpunit
```

--------------------------------

### Get Temporary Filename

Source: https://github.com/codeigniter4/userguide/blob/master/docs/libraries/uploaded_files.html

Gets the full path of the temporary file created during the upload process using the `getTempName()` method.

```APIDOC
## Get Temporary Filename

### Description
Gets the full path of the temporary file created during the upload process using the `getTempName()` method.

### Method
```php
$file->getTempName()
```

### Parameters
None

### Response
- string: The full path to the temporary file.

### Example
```php
$tempfile = $file->getTempName();
```
```

--------------------------------

### Configure VirtualHost for Application

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/running.html

Set up a VirtualHost element in your Apache configuration to serve your application.

```apache
<VirtualHost *:80>
    DocumentRoot "/opt/lamp/apache2/myproject/public"
    ServerName   myproject.local
    ErrorLog     "logs/myproject-error_log"
    CustomLog    "logs/myproject-access_log" common

    <Directory "/opt/lamp/apache2/myproject/public">
        AllowOverride All
        Require all granted
    </Directory>
</VirtualHost>
```

--------------------------------

### getGetPost() Method

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Combines GET and POST data, prioritizing GET values in case of conflicts. Supports filtering and flags.

```APIDOC
## getGetPost()

### Description
Retrieves data from both GET and POST streams, prioritizing GET values if keys conflict. It allows fetching a specific variable or combined streams, with options for filtering and flags.

### Method
`getGetPost(string $index = null, int $filter = null, int $flags = null)`

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```php
// Get a specific variable from GET or POST (GET preferred)
$request->getGetPost('field1');

// Get all GET and POST data combined (GET preferred on conflict)
$request->getGetPost();

// Get combined data with specific filtering
$request->getGetPost(null, FILTER_SANITIZE_STRING);
```

### Response
#### Success Response (200)
Returns `$_GET` and `$_POST` combined if no parameters specified (prefer GET value on conflict), otherwise looks for GET value, if nothing found looks for POST value, if no value found returns null.

Return type: `array|bool|float|int|object|string|null`

#### Response Example
```json
{
  "field1": "get_value_or_post_value",
  "field2": "post_only_value"
}
```
```

--------------------------------

### Install Specific Version of CodeIgniter App Starter

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/installing_composer.html

To install a specific version of the CodeIgniter app starter, append the desired version number to the command. This is useful for testing or maintaining compatibility.

```bash
composer create-project codeigniter4/appstarter:4.4.8 project-root
```

--------------------------------

### getGet() Method

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Retrieves GET data, with options for filtering and flags. If the first parameter is null, it returns all GET data.

```APIDOC
## getGet()

### Description
Retrieves GET data from the incoming request. It allows for specifying an index to fetch a specific variable, applying filters, and setting flags for sanitation. If the first parameter is null, all GET items are returned and passed through the specified filter.

### Method
`getGet(string $index = null, int $filter = null, int $flags = null)`

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```php
// Get all GET data with default filtering
$request->getGet(null);

// Get all GET data with specific sanitation
$request->getGet(null, FILTER_SANITIZE_FULL_SPECIAL_CHARS);

// Get a specific GET variable with sanitation
$request->getGet('user_id', FILTER_SANITIZE_NUMBER_INT);

// Get multiple GET variables with specific filters and flags
$request->getGet(['id', 'page'], FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_HIGH);
```

### Response
#### Success Response (200)
Returns `$_GET` if no parameters supplied, otherwise the GET value if found, or null if not.

Return type: `array|bool|float|int|object|string|null`

#### Response Example
```json
{
  "search_term": "example query",
  "page": "2"
}
```
```

--------------------------------

### Start Local Development Server with Specific PHP Version

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/running.html

Use the --php CLI option to specify a particular PHP executable path for the local development server. This allows testing with different PHP versions.

```bash
php spark serve --php /usr/bin/php7.6.5.4
```

--------------------------------

### Retrieve Specific GET Parameters

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Retrieve specific GET parameters by passing an array of keys. Filtering can also be applied.

```php
$request->getGet(['field1', 'field2']);
```

```php
$request->getGet(['field1', 'field2'], FILTER_SANITIZE_FULL_SPECIAL_CHARS);
```

--------------------------------

### CodeIgniter 3.x Controller Example

Source: https://github.com/codeigniter4/userguide/blob/master/docs/installation/upgrade_controllers.html

This is an example of a controller in CodeIgniter 3.x. It extends CI_Controller and uses echo to output a string.

```php
<?php

class Helloworld extends CI_Controller
{
    public function index($name)
    {
        echo 'Hello ' . html_escape($name) . '!';
    }
}
```

--------------------------------

### Install CodeIgniter DevKit

Source: https://github.com/codeigniter4/userguide/blob/master/docs/extending/composer_packages.html

Installs the CodeIgniter DevKit and related development tools. This command should be run in the root of your package directory.

```bash
composer config minimum-stability dev
composer config prefer-stable true
composer require --dev codeigniter4/devkit
```

--------------------------------

### Add a custom environment boot file

Source: https://github.com/codeigniter4/userguide/blob/master/docs/general/environments.html

To add custom environments, you need to add boot files for them. Copy an existing boot file and customize it.

```bash
# Example: Copy production boot file to staging
# cp APPPATH/Config/Boot/production.php APPPATH/Config/Boot/staging.php
```

--------------------------------

### Filter All GET Items

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Retrieve all GET items and apply a filter for sanitation. Set the first parameter to null to process all items.

```php
$request->getGet(null, FILTER_SANITIZE_FULL_SPECIAL_CHARS);
```

--------------------------------

### Getting Variable Data (Legacy)

Source: https://github.com/codeigniter4/userguide/blob/master/docs/incoming/incomingrequest.html

Retrieves data from `$_REQUEST` (GET, POST, COOKIE). Use with caution as it's for backward compatibility.

```APIDOC
## getVar()

### Description
Retrieves data from `$_REQUEST` (GET, POST, COOKIE). This method exists for backward compatibility and should not be used in new projects. It may lead to unexpected overrides if not used carefully, especially with POST data potentially being overridden by cookies.

If the incoming request has a `Content-Type` header set to `application/json`, this method returns the JSON data instead of `$_REQUEST` data.

### Method
`getVar()`

### Endpoint
N/A (Method of a Request object)

### Parameters
None

### Request Example
```php
$request->getVar()
```

### Response
Returns data from `$_REQUEST` or JSON data if applicable.
```