LessCss Compile Service

This small library uses the official Java LessCss Compiler and provides a simple interface to compile LESS code, LESS files, and LESS files in the servlet context.

The library was created to provide on-the-fly LESS compilation within a controller that ships the compiled CSS back to the browser. This simplifies LESS development as developers write LESS code that is published automatically to your servlet container which is integrated with your IDE (tested on Eclipse + Tomcat). This way there is no need for additional build management to compile LESS or even manual compilation.

For production environment a small "caching" layer was added. However this is only optional and can be replaced with your preferred caching mechanism that is already in place.

Usage

This library was intended to be used with Spring or any other IoC container. It provides a singleton LessCompileService that should be injected in your services or controller that need to compile LESS code.

The following is a small example of a Spring configuration and a Spring MVC Controller to publish compiled LESS files:

Spring Config

<bean id="lessCompileService"
	class="com.hastybox.lesscss.compileservice.CachingWebLessCompileServiceWrapper">
	<property name="compileService">
		<bean
			class="com.hastybox.lesscss.compileservice.SimpleWebLessCompileService">
			<property name="basePath" value="/WEB-INF/less/" />
			<property name="lessCompiler">
				<bean
					class="com.hastybox.lesscss.compileservice.compiler.LessCssLessCompilerWrapper">
					<property name="compress" value="true" />
				</bean>
			</property>
		</bean>
	</property>
</bean>

Controller code

@Controller
public class LessController {

	@Autowired
	private WebLessCompileService lessCompileService;

	@RequestMapping({ "/css/*.css", "/css/*/*.css" })
	public void retrieveCss(HttpServletRequest request, HttpServletResponse response) throws Exception {

		String requestPath = request.getRequestURI();

		String regex = "^.+/css/(.*)\\.css";
		Pattern pattern = Pattern.compile(regex);
		Matcher matcher = pattern.matcher(requestPath);

		if (!matcher.find()) {
			throw new Exception("this is not working");
		}

		String filePath = matcher.group(1) + ".less";

		String cssCode = lessCompileService.compileFromPath(filePath, request.getSession().getServletContext());

		response.getWriter().write(cssCode);
	}
}