Adding common functions docs.

Author: lonnieezell

system/Common.php

@@ -248,9 +248,9 @@ function service(string $name, ...$params)
 
 //--------------------------------------------------------------------
 
-if (! function_exists('sharedService'))
+if (! function_exists('shared_service'))
 {
-	function sharedService(string $name, ...$params)
+	function shared_service(string $name, ...$params)
 	{
 		// Ensure the number of params we are passing
 		// meets the number the method expects, since

user_guide_src/source/general/common_functions.rst

@@ -0,0 +1,155 @@
+################
+Common Functions
+################
+
+CodeIgniter uses provides a few functions that are globally defined, and are available to you at any point. These
+do not require loading any additional libraries or helpers.
+
+.. contents:: Page Contents
+	:local:
+
+
+.. php:function:: log_message ($level, $message [, array $context])
+
+	:param   string   $level: The level of severity
+	:param   string   $message: The message that is to be logged.
+	:param   array    $context: An associative array of tags and their values that should be replaced in $message
+	:returns: TRUE if was logged succesfully or FALSE if there was a problem logging it
+	:rtype: bool
+
+	Logs a message using the Log Handlers defined in **application/Config/Logger.php**.
+
+	Level can be one of the following values: **emergency**, **alert**, **critical**, **error**, **warning**,
+	**notice**, **info**, or **debug**.
+
+	Context can be used to substitute values in the message string. For full details, see the
+	:doc:`Logging Information <logging>` page.
+
+.. php:function:: view ($name [, $data [, $options ]])
+
+	:param   string   $name: The name of the file to load
+	:param   array    $data: An array of key/value pairs to make available within the view.
+	:param   array    $options: An array of options that will be passed to the rendering class.
+	:returns: The output from the view.
+	:rtype: string
+
+	Grabs the current RenderableInterface-compatible class
+	and tells it to render the specified view. Simply provides
+	a convenience method that can be used in Controllers,
+	libraries, and routed closures.
+
+	The $option array is not used by CodeIgniter, but is provided to facilitate third-party integrations with
+	libraries like Twig.
+
+	Example::
+
+		$data = ['user' => $user];
+
+		echo view('user_profile', $data);
+
+	For more details, see the :doc:`Views <views>` page.
+
+.. php:function:: esc ( $data, $context='html' [, $encoding])
+
+	:param   string|array   $data: The information to be escaped.
+	:param   string   $context: The escaping context. Default is 'html'.
+	:param   string   $encoding: The character encoding of the string.
+	:returns: The escaped data.
+	:rtype: string
+
+	Escapes data for inclusion in web pages, to help prevent XSS attacks.
+	This uses the Zend Escaper library to handle the actual filtering of the data.
+
+	If $data is a string, then it simply escapes and returns it.
+	If $data is an array, then it loops over it, escaping each 'value' of the key/value pairs.
+
+	Valid context values: html, js, css, url, attr, raw, null
+
+.. php:function:: is_cli ()
+
+	:returns: TRUE if the script is being executed from the command line or FALSE otherwise.
+	:rtype: bool
+
+.. php:function:: route_to ( $method [, ...$params] )
+
+	:param   string   $method: The named route alias, or name of the controller/method to match.
+	:param   mixed   $params: One or more parameters to be passed to be matched in the route.
+
+	Generates a relative URI for you based on either a named route alias, or a controller::method
+	combination. Will take parameters into effect, if provided.
+
+	For full details, see the :doc:`routing` page.
+
+.. php:function:: service ( $name [, ...$params] )
+
+	:param   string   $name: The name of the service to load
+	:param   mixed    $params: One or more parameters to pass to the service method.
+	:returns: An instance of the service class specified.
+	:rtype: mixed
+
+	Provides easy access to any of the :doc:`Services <../concepts/services>` defined in the system.
+
+	Example::
+
+		$logger = service('logger');
+		$renderer = service('renderer', APPPATH.'views/');
+
+.. php:function:: shared_service ( $name [, ...$params] )
+
+	:param   string   $name: The name of the service to load
+	:param   mixed    $params: One or more parameters to pass to the service method.
+	:returns: An instance of the service class specified.
+	:rtype: mixed
+
+	Identical to the **service()** function described above, except that all calls to this
+	function will share the same instance of the service, where **service** returns a new
+	instance every time.
+
+.. php:function:: remove_invisible_characters($str[, $url_encoded = TRUE])
+
+	:param	string	$str: Input string
+		:param	bool	$url_encoded: Whether to remove URL-encoded characters as well
+		:returns:	Sanitized string
+		:rtype:	string
+
+		This function prevents inserting NULL characters between ASCII
+		characters, like Java\\0script.
+
+		Example::
+
+		remove_invisible_characters('Java\\0script');
+		// Returns: 'Javascript'
+
+.. php:function:: load_helper( $filename )
+
+	:param   string   $filename: The name of the helper file to load.
+
+	Loads a helper file.
+
+	For full details, see the :doc:`helpers` page.
+
+.. php:function:: get_csrf_token_name ()
+
+	:returns: The name of the current CSRF token.
+	:rtype: string
+
+	Returns the name of the current CSRF token.
+
+.. php:function:: get_csrf_hash ()
+
+	:returns: The current value of the CSRF hash.
+	:rtype: string
+
+	Returns the current CSRF hash value.
+
+.. php:function:: force_https ( $duration = 31536000 [, $request = null [, $response = null]] )
+
+	:param  int  $duration: The number of seconds browsers should convert links to this resource to HTTPS.
+	:param  RequestInterface $request: An instance of the current Request object.
+	:param  ResponseInterface $response: An instance of the current Response object.
+
+	Checks to see if the page is currently being accessed via HTTPS. If it is, then
+	nothing happens. If it is not, then the user is redirected back to the current URI
+	but through HTTPS. Will set the HTTP Strict Transport Security header, which instructs
+	modern browsers to automatically modify any HTTP requests to HTTPS requests for the $duration.
+