Creating a debug controller

@DebugWebController

Debug web controllers are just like any other controller bean with RequestMapping methods, except they are annotated with @DebugWebController instead of the standard @Controller. Any bean annotated with @DebugWebController will be picked up by the DebugWebModule and will have its mappings prefixed with the debug web root path.

Simple custom debug web controller mapped on /ROOT_PATH/test
@DebugWebController
public class DebugEhcacheController
{
	@RequestMapping(value = "/test", method = RequestMethod.GET)
	public String test() {
		return "th/mymodule/debug/test";
	}
}

Thymeleaf template

Unless a named template is specified, the default Thymeleaf template from debug web will be applied to the output. The default template will add a top menu for all registered debug web controllers. Like any Across web Thymeleaf template, this implementation requires you to put the actual output in a content fragment.

A Thymeleaf view file for my controller
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
	<title>My test debug controller</title>
</head>
<body th:fragment="content">
	This is a test debug controller.
</body>
</html>

If you need additional javascript or custom CSS, you can register it using the WebResourceRegistry and it will automatically be added to the output by the layout template.

Adding custom CSS with the WebResourceRegistry
@DebugWebController
public class DebugEhcacheController
{
	@ModelAttribute
	public void registerCss( WebResourceRegistry registry ) {
		registry.addWithKey( WebResource.CSS, "MyModule", "/css/mymodule/debug.css", WebResource.VIEWS );
	}

	@RequestMapping(value = "/test", method = RequestMethod.GET)
	public String test() {
		return "th/mymodule/debug/test";
	}
}

Customizing the top menu

The default layout template builds and renders a top menu. This menu is built by publishing a DebugMenuEvent. Any AcrossEventHandler - and all controllers are event handlers by default - can listen for this event and modify the menu. The menu is built using a PathBasedMenuBuilder, allowing the entire menu hierarchy to be specified using a path structure.

By default the menu item path is also used as the url for the menu endpoint. All menu item urls will be processed by the debug web WebAppPathResolver and any relative path will be prefixed with the configured root path.
Example of registering a new top-level menu item pointing to /ROOT_PATH/test
@DebugWebController
public class DebugEhcacheController
{
	@Event
	public void registerMenuItem( DebugMenuEvent event ) {
		event.builder().item( "/test", "Test controller" );
	}

	@RequestMapping(value = "/test", method = RequestMethod.GET)
	public String test() {
		return "th/mymodule/debug/test";
	}
}

Linking to debug web controllers

The actual URL endpoint of debug web controllers depends on the application-specific configured root path. When implementing custom debug web controllers you can ensure your relative links point to the correct controller by running them through the PrefixingPathContext. DebugWebModule has registered a prefixer named debugWeb, this prefixer can be used to correctly point to a debug web controller from any other controller.

Relative links from Thymeleaf views
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
	<title>My test debug controller</title>
</head>
<body th:fragment="content">
	Relative to debug web root path:
	* <a th:href="@{#webapp.path('/test')}">when rendered from a debug web controller</a>
	* <a th:href="@{'@debugWeb:/test'}">always</a>
</body>
</html>

In code the DebugWeb bean - implementation of the PrefixingPathContext - can be used to generate the correct URL.

Example of generating a debug controller redirect
@DebugWebController
public class DebugEhcacheController
{
	@Autowired
	private DebugWeb debugWeb;

	@RequestMapping(value = "/redirect", method = RequestMethod.GET)
	public String test() {
		return debugWeb.redirect( "/test" );
	}
}

Adding custom interceptors

If you want to add interceptors only to debug web controllers, you can register them using an instance of DebugWebConfigurerAdapter or any custom PrefixingHandlerMappingConfigurer that supports the DebugWebModule mapper.

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