GeSHi for CodeIgniter

GeSHi is a syntax-highlighter that provides server-side highlighting for over 100 programming languages. This library provides a simple, clean GeSHi API tailored for use in CodeIgniter projects.

Features:

Works with CodeIgniter v1.7.3 and newer
Highlight any string on-the-fly using GeSHi
GeSHi library is included. No external dependencies
Easy to use with the display_override hook for automated highlighting of select blocks inside view files
Ability to drop-in newer (or older) versions of GeSHi with this library

Installation

Download the latest version from the Github page
Copy the geshilib.php file and geshi folder into your application/libraries folder.

Loading the Library

Like any other library in CodeIgniter, use the $this->load->library function to load geshilib:


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

Basic Syntax Highlighting

Once the library is loaded, you can use GeSHi to highlight any string by calling the $this->geshilib->highlight method.

For example, to highlight a string $mycode, which contains SQL code: $this->geshilib->highlight($mycode, 'sql');

The second argument ('sql') is the language you want to use for highlighting. Any language that GeSHi supports is valid. Refer to the GeSHi Homepage for a list of supported langauges (hint: they're pretty much all supported).

If you don't specify a second argument, GeSHiLib will highlight your code using simple BASH highlighting.

The $this->geshilib->filter method accepts a third argument, $params. See "Setting Paramters" below for more information regarding this argument.

Highlighting Code Blocks inside of HTML

GeSHi lib can parse HTML output and look for code to highlight. Place the code you wish to highlight between <sourcecode>...</sourcecode> tags within your HTML code, and then send the HTML to the $this->geshilib->filter method:

$my_html = "<p>Some regular content</p><sourcecode>$x = "Hello, World!";</sourcecode>";

$highlighted = $this->geshilib->filter($my_html);

To specify a language, add the language attribute to the sourcecode tag:

$my_html = "<p>Some regular content</p><sourcecode language='php'>$x = "Hello, World!";</sourcecode>";

$highlighted = $this->geshilib->filter($my_html);

Don't worry that <sourcecode>...</sourcecode> tags aren't valid HTML. GeSHi will conver them to <pre>...</pre> tags.

The $this->geshilib->filter method also accepts a second argument, $params. See "Setting Paramaters" below for more information regarding this argument.

Automating GeshiLib with a Output Hook

If you want Geshilib to automatically highlight all content contained within <sourcecode>...</sourcecode> tags inside of your views, you can create a hook.

Ensure that hooks are enabled in the application/config/config.php file: $config['enable_hooks'] = TRUE;

Add the following code to your application/config/hooks.php file:

$hook['display_override'] = array(
	'class' => 'Geshilib',
	'function' => 'geshi_display_override',
	'filename' => 'geshilib.php',
	'filepath' => 'libraries',
	'params' => array());

Manually Finding and Highlighting Code in CI View Files

To automatically find and highlight all <sourcecode>...</sourcecode> inside of a CodeIgniter view file, load the view into a string using $this->load->view, run $this->geshilib->filter on it, and manually output the results using $this->output->set_output:

$vdata = $this->load->view('some_view', $some_data);
$vdata = $this->geshilib->filter($vdata);
$this->output->set_output($vdata);

Setting Parameters

GeSHi provides several options for customizing highlighted code. You can specify these parameters by adding the $params array argument to the highlight or filter methods, or by specifying content for the params array in the display_override hook.

The $params variable is an associative array. The key is the parameter name, and the value is an array of options for the parameter. Parameters in the $params array are the same as methods in the GeSHi object. Almost any public method in a GeSHi object can be the a key in the $params array. Exceptions include the error(), parse_code(), and get_stylesheet() methods. Values in the $params array are the arguments that the GeSHi object method accepts.

For example, the GesHi object contains a public method, enable_line_numbers() that accepts two arguments: a GeSHi constant, and an optional integer. To use this method, you would set your parameters array as follows:

$params = array(
	'enable_line_numbers' => array(GESHI_NORMAL_LINE_NUMBERS, 15)
);

$this->geshilib->highlight($some_code, $params);

For a full documentation of methods that the GeSHi object supports, refer to the GeSHi Documentation.

Some Common Parameters

Note: This list is not comprehensive. Refer to the GeSHi Documentation for all methods/parameters.

Note: This parameters list refers to GeSHi v1.0.8.10 API. If you are using a different version of GeSHi with this library, this API may be different.

Parameter	Options	Description
set_header_type	GESHI_HEADER_DIV GESHI_HEADER_PRE GESHI_HEADER_PRE_VALID GESHI_HEADER_PRE_TABLE GESHI_HEADER_NONE	Sets the header type for highlighted sourcecode.
enable_line_numbers	GESHI_NORMAL_LINE_NUMBERS GESHI_FANCY_LINE_NUMBERS GESHI_NO_LINE_NUMBERS
set_line_style	Any desired CSS code
start_line_numbers_at	Any positive integer
enable_classes	TRUE to enable classes FALSE to disable classes
set_overall_class	desired class name
set_overall_id	desired ID
set_overall_style	desired CSS code
set_line_style	desired even line style, desired odd line style
set_tab_width	any positive integer
enable_ids	TRUE to enable ID's FALSE to disable ID's

Other Parameters

The following parameters apply to the geshilib library, not GeSHi itself:

Parameter	Default	Options	Description
fail_gracefully	TRUE	TRUE or FALSE	If FALSE, GeSHi will throw exceptions if it encounters an error during highlighting. Useful for debugging.
default_language	BASH	Any GeSHi-supported Language	Set the default language in case none is specified.

Examples of Setting Parameters

The following example enables line numbers and sets tabs to 3 characters:

$params = array('enable_line_numbers' => array(GESHI_NORMAL_LINE_NUMBERS), 'set_tab_width' => array('3'));

$this->geshilib->highlight("echo 'Hello World';", 'php', $params);

The following example enable line numbers and adds an overall class to GeSHi output for all <sourcecode>...</sourcecode> instances encountered when using the display_override hook:

$hook['display_override'] = array(
	'class' => 'Geshilib',
	'function' => 'geshi_display_override',
	'filename' => 'geshilib.php',
	'filepath' => 'libraries',
	'params' => array(
		'enable_line_numbers' => array('GESHI_FANCY_LINE_NUMBERS', 10), 'set_overall_class' => array('sourcecode')
	));

Note: Because of the way CodeIgniter loads libraries, you must refer to all GeSHi constants as strings inside your application/config/hooks.php file. For example, the constant GESHI_FANCY_LINE_NUMBERS would become the string 'GESHI_FANCY_LINE_NUMBERS' inside your parameters array.

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