Request Interception Points

Request interception points are announced by the Application.bx listener

The following interception points are announced on every request by the Application.bx listeners. Please note that to listen to these request events, your listener must also be registered for every request.

Registration

Our advice is to register your listener in either the onApplicationStart() or onRequestStart() methods of the Application.bx. You will use the boxRegisterRequestInterceptor() BIF in order to register them.

class{

    function onApplicationStart(){
        boxRegisterRequestInterceptor( classOrLambda )
    }
    
    function onRequestStart( required string targetPage ){
        boxRegisterRequestInterceptor( classOrLambda )
    }

}

Interception Points

These events occur around the life cycle of the request listener Application.bx:

• onAbort

• onApplicationEnd

• onApplicationStart

• onClassRequest

• onError

• onMissingTemplate

• onRequest

• onRequestEnd

• onRequestStart

• onSessionEnd

• onSessionStart

onAbort

This event is triggered whenever an abort component is executed.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

Args Key	Type	Description
targetPage	string	The target page that was aborted

Example

class myListener{
	function onAbort( struct data ){

	}
}

onApplicationEnd

This event is triggered when the application has timed out or is being shut down. It could also happen if the application is being reloaded or the server is being restarted or shut down.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

Args Key	Type	Description
applicationScope	struct	The application scope

Example

class myListener{
	function onApplicationEnd( struct data ){
		// This is where you would do any cleanup
		// or save the application scope to a file
	}
}

onApplicationStart

This event is triggered when the application is started and it's guaranteed to be synchronized. This could be when the server is started or when the application is reloaded as well. Every time an application times out, this event will be triggered again upon startup. This is a great place to initialize your application.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

None

Example

class myListener{
	function onApplicationStart( struct data ){

	}
}

onClassRequest

This event is triggered whenever a class is being executed remotely via HTTP or any type of remote request. If you implement this event, you can intercept the request and do any type of processing before the class is executed. This is a great place to implement security checks or any type of processing that needs to be done before the class is executed.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

Args Key	Type	Description
className	string	The name of the executing class
methodName	string	The name of the requested method
params	struct	The parameters being passed to the requested executing method
classInstance	object	The instance of the class being executed

Example

class myListener{
	function onClassRequest( struct data ){
		// This is where you would do any security checks
		// or any type of processing that needs to be done
		// before the class is executed.
		
		// You can also call the class method here if you want
		// to execute it yourself.
		
		var result = data.classInstance.invoke( data.methodName, data.params );
		
		return result;	
	}
}

onError

This event is triggered whenever an uncaught exception occurs anywhere in your application. This is a great place to log the error or send an email to the administrator. You can also use this event to display a custom error page or redirect the user to a different page.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

Args Key	Type	Description
exception	Throwable	The caugth exception

Example

class myListener{
	function onError( struct data ){
		// This is where you would log the error
		// or send an email to the administrator.
		
		// You can also use this event to display a custom error page
		// or redirect the user to a different page.
		var exception = data.args.exception;
		
	}
}

onMissingTemplate

This event is triggered whenever a template that's being requested for execution is not found. This is a great place to log the error or send an email to the administrator or handle it dynamically.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

Args Key	Type	Description
targetPage	string	The target page that was not found

Example

class myListener{
	function onMissingTemplate( struct data ){
		// This is where you would log the error
		// or send an email to the administrator.
		
		// You can also use this event to display a custom error page
		// or redirect the user to a different page.
		var targetPage = data.args.targetPage;
	}
}

onRequest

This event is triggered whenever a request is being executed, right after the onRequestStart, onClassRequest events. This is a great place to do any type of processing that needs to be done before the request is executed.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

Args Key	Type	Description
targetPage	string	The target page that was requested

Example

class myListener{
	function onRequest( struct data ){
		// This is where you would do any type of processing
		// that needs to be done before the request is executed.
		var targetPage = data.args.targetPage;
	}
}

onRequestEnd

This event is triggered once the request has been executed and the response is being sent back to the client. This is a great place to do any type of processing that needs to be done after the request is executed.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

None

Example

class myListener{
	function onRequestEnd( struct data ){
		// This is where you would do any type of processing
		// that needs to be done after the request is executed.
		
		// You can also use this event to display a custom error page
		// or redirect the user to a different page.
	}
}

onRequestStart

This event is triggered at the beginning of the request, right before the onClassRequest event. This is a great place to do any type of processing that needs to be done before the request is executed.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

Args Key	Type	Description
targetPage	string	The target page that was requested

Example

class myListener{
	function onRequestStart( struct data ){
		// This is where you would do any type of processing
		// that needs to be done before the request is executed.
		
		var targetPage = data.args.targetPage;
		
		// You can also use this event to display a custom error page
		// or redirect the user to a different page.
	}
}

onSessionEnd

This event is triggered when the session has timed out or is being shut down.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

Args Key	Type	Description
sessionScope	struct	The session scope being shutdown
applicationScope	struct	The application scope linked to the session

Example

class myListener{
	function onSessionEnd( struct data ){
		// This is where you would do any cleanup
		// or save the session scope to a file
		// or do any type of processing that needs to be done
		// before the session is shutdown.
		var sessionScope = data.args.sessionScope;
		var applicationScope = data.args.applicationScope;
	}
}

onSessionStart

This event is triggered when the session is started. This is a great place to initialize your session or do any type of processing that needs to be done before the session is started.

Data Structure

Data Key	Type	Description
args	struct	The arguments relating the event
application	Application	The BoxLang Application class
context	IBoxContext	The BoxLang Request context
listener	BaseApplicationListener	The BoxLang listener class

Args Structure

Args Key	Type	Description
sessionID	string	The session identifier

Example

class myListener{
	function onSessionStart( struct data ){
		// This is where you would do any type of processing
		// that needs to be done before the session is started.
		
		var sessionID = data.args.sessionID;
		
		// You can also use this event to display a custom error page
		// or redirect the user to a different page.
	}
}