Provides functionality to perform syntax highlighting for different file formats.

1. Introduction

With Text_Highlighter it is possible to create syntax highlighted versions of different file formats.

Currently, the following formats are supported:

• ABAP
• C++
• CSS
• output of diff(1)
• DTD
• HTML
• Java
• Javascript
• MySQL
• Perl
• PHP
• Python
• Ruby
• sh
• SQL
• VBScript
• XML

There are different options for getting the results of the highlighting, through the use of renderers. The list of renderers is as follows.

• Array
• Console
• HTML - using span-tags containing a CSS class name, this is the default renderer
• HTMLTags - using simple set of tags, only B, I and U, useful for devices that support only a subset of HTML (example is an iPod)
• JSON
• XML

2. Usage

The class Text_Highlighter contains all necessary functionality to perform the syntax highlighting except for the actual highlighting rules for the different formats. These rules are defined in subclasses of Text_Highlighter, but one must not directly instantiate these subclasses. Instead the object-oriented factory pattern is used to create a highlighter object depending on the format:

Highlighting a SQL query

<?php
require_once 'Text/Highlighter.php';
 
$hlSQL =& Text_Highlighter::factory('SQL');
echo $hlSQL->highlight("SELECT * FROM some_table WHERE id = 12");

This code generates a highlighted version of the SQL SELECT-query that is passed to Text_Highlighter::highlight in HTML. It is possible to customize the output to e.g. instead generate output suitable for usage on a console. This is described in the section Output Customization.

In order to produce syntax highlighting for other formats, one must replace the argument value SQL of Text_Highlighter::factory with one of ABAP, CPP, CSS, DIFF, DTD, HTML, JAVA, JAVASCRIPT, MYSQL, PERL, PHP, PYTHON, RUBY, SQL, or XML.

3. Output Customization

The default behaviour of Text_Highlighter is to generate a syntax highlighted HTML version of the input.

It is possible to instead generate output that is suitable for being displayed on color-capable terminals such as xterm or through less(1) by telling Text_Highlighter to use another renderer:

Using the console renderer

<?php
require_once 'Text/Highlighter.php';
require_once 'Text/Highlighter/Renderer/Console.php';
 
$hlSQL =& Text_Highlighter::factory('SQL');
$hlSQL->setRenderer(new Text_Highlighter_Renderer_Console);
echo $hlSQL->highlight("SELECT * FROM some_table WHERE id = 12");

Also it is possible to further customize the output of both the HTML- and the console-renderer by passing an associative array of options to the constructor:

Options for the HTML renderer

<?php
require_once 'Text/Highlighter.php';
require_once 'Text/Highlighter/Renderer/Html.php';
 
$renderer = new Text_Highlighter_Renderer_Html(['numbers' => HL_NUMBERS_LI, 'tabsize' => 4]);
 
$hlJava =& Text_Highlighter::factory('JAVA');
$hlJava->setRenderer($renderer);
 
echo $hlJava->highlight('class JavaProgram {
    public static void main(String args[]) {
        System.out.println("Hello World!");
    }
}');

The above example configures a HTML renderer with two options: The first one tells it to number the lines in the output using the <ol> HTML tag and the second one instructs the renderer to use a tab width of 4 spaces for indentation.

The following options are applicable:

Possible options for the renderer classes