Added helper file with http related functions.

application/helpers/http_helper.php

@@ -0,0 +1,175 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Open Source Web Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) 2013 - 2020, Alex Tselegidis
+ * @license     http://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        http://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+if ( ! function_exists('request'))
+{
+    /**
+     * Gets the value of a request variable.
+     *
+     * Example:
+     *
+     * $first_name = request('first_name', 'John');
+     *
+     * @param string|null $key Request variable key.
+     * @param mixed $default Default value in case the requested variable has no value.
+     *
+     * @return mixed
+     *
+     * @throws InvalidArgumentException
+     */
+    function request(string $key, $default = NULL)
+    {
+        /** @var EA_Controller $CI */
+        $CI = &get_instance();
+
+        if (empty($key))
+        {
+            throw new InvalidArgumentException('The $key argument cannot be empty.');
+        }
+
+        return $CI->input->post_get($key) ?? $default;
+    }
+}
+
+if ( ! function_exists('response'))
+{
+    /**
+     * Return a new response from the application.
+     *
+     * Example:
+     *
+     * response('This is the response content', 200, []);
+     *
+     * @param string $content
+     * @param int $status
+     * @param array $headers
+     */
+    function response(string $content = '', int $status = 200, array $headers = [])
+    {
+        /** @var EA_Controller $CI */
+        $CI = &get_instance();
+
+        $CI
+            ->output
+            ->set_output($content);
+    }
+}
+
+if ( ! function_exists('response'))
+{
+    /**
+     * Return a new response from the application.
+     *
+     * @param string $content
+     * @param int $status
+     * @param array $headers
+     */
+    function response(string $content = '', int $status = 200, array $headers = [])
+    {
+        /** @var EA_Controller $CI */
+        $CI = &get_instance();
+
+        foreach ($headers as $header)
+        {
+            $CI->output->set_header($header);
+        }
+
+        $CI
+            ->output
+            ->set_status_header($status)
+            ->set_output($content);
+    }
+}
+
+if ( ! function_exists('json_response'))
+{
+    /**
+     * Return a new response from the application.
+     *
+     * Example:
+     *
+     * json_response([
+     *  'message' => 'This is a JSON property.'
+     * ]);
+     *
+     * @param array $content
+     * @param int $status
+     * @param array $headers
+     */
+    function json_response(array $content = [], int $status = 200, array $headers = [])
+    {
+        /** @var EA_Controller $CI */
+        $CI = &get_instance();
+
+        foreach ($headers as $header)
+        {
+            $CI->output->set_header($header);
+        }
+
+        $CI
+            ->output
+            ->set_status_header($status)
+            ->set_content_type('application/json')
+            ->set_output($content);
+    }
+}
+
+if ( ! function_exists('json_exception'))
+{
+    /**
+     * Return a new json exception from the application.
+     *
+     * Example:
+     *
+     * json_exception($exception); // Add this in a catch block to return the exception information.
+     *
+     * @param Throwable $exception
+     */
+    function json_exception(Throwable $exception)
+    {
+        json_response([
+            'message' => $exception->getMessage(),
+            'trace' => config('debug') ? $exception->getTrace() : []
+        ], 500);
+    }
+}
+
+
+if ( ! function_exists('abort'))
+{
+    /**
+     * Throw an HttpException with the given data.
+     *
+     * Example:
+     *
+     * if ($error) abort(500);
+     *
+     * @param int $code
+     * @param string $message
+     * @param array $headers
+     *
+     * @return void
+     */
+    function abort(int $code, string $message = '', array $headers = [])
+    {
+        /** @var EA_Controller $CI */
+        $CI = &get_instance();
+
+        foreach ($headers as $header)
+        {
+            $CI->output->set_header($header);
+        }
+
+        show_error($message, $code);
+    }
+}