Welcome to WEB 2.0Welcome to WEB 2.0An Open Laszlo presentationAn Open Laszlo presentation

Part 2Part 2

Carlos Fernando Scheidecker AntunesCarlos Fernando Scheidecker Antunesantunes@cs.utah.eduantunes@cs.utah.edu

http://www.cs.utah.edu/~antunes/AJAXhttp://www.cs.utah.edu/~antunes/AJAX

Feb 15 2006

What is WEB 2.0?What is WEB 2.0?

• Web 2.0 is a term often applied to a perceived ongoing transition of the World Wide Web from a collection of websites to a full-fledged computing platform serving web applications to end users. Ultimately Web 2.0 services are expected to replace desktop computing applications for many purposes.

What is Laszlo ?What is Laszlo ?

What is Laszlo ?What is Laszlo ?

• Laszlo is a rich client platform for web application.

• Without realizing, it was the first AJAX application I ever written back in 2004

• It uses Flash, Java, XML and a Servlet engine to provide a rich client desktop like experience for the user.

• It is the future of web and client server applications

Laszlo’s ComponentsLaszlo’s Components

• Compiler

Takes the XML text file (.lzx) and produces the executable in Flash.

• CGI

Use a Servlet, PHP, ASP.net to optionally provide http based SOAP and XML-RPC web services.

Laszlo’s ComponentsLaszlo’s Components

• Run time Framework

Set of Servlets that provide user interface components, data binding, timer, Asynchronous network services

Laszlo OverviewLaszlo Overview

Coding with LaszloCoding with Laszlo

• It is important to understand that Laszlo provides the user side. You can embed JavaScript within your Laszlo XML source code to program the client side.

• Laszlo is the View share of the MVC pattern.

• The business side resides on the CGI applications that provide data for the Desktop much like an AJAX pattern.

Example of Laszlo codeExample of Laszlo code• This is a simple valid LZX source file. Note the XML format:

<canvas>

• <dataset name="dset" • autorequest="true" type="http" • src="getemployees.jsp"/>

• <simplelayout axis="y"/>

• <view datapath="dset:/phonebook/employee">• <simplelayout axis="x"/>• <text datapath="firstName/text()"/>• <text datapath="lastName/text()"/>• <text datapath="phone/text()"/>• </view>

• </canvas>

Development cycleDevelopment cycle

• Develop a Laszlo application requires the following steps:

1 - Define the data sources writing the appropriate CGI programs. These programs will work like a dynamic web application with the difference that data not content is provided and the format is XML

Development cycleDevelopment cycle

• Develop a Laszlo application requires the following steps:

2 – Write the Laszlo source code and compile it through the Laszlo compiler which is a Servlet living inside a container like Tomcat

Development cycleDevelopment cycle

• Develop a Laszlo application requires the following steps:

3 – Test your application

4 – Deploy the application

What’s the catch?What’s the catch?

• Laszlo is a great platform but it requires:

1 – Patience, it takes a while to compile the lzx.

2 – It is hard to code, you need to write a few applications to get proficiency with the platform. Learning curve.

3 – Understand AJAX and GUI application development.

4 – For large deployments clustering load balancing is a must.

QuestionsQuestions

Have any questions, concerns or fears?

This is the time.

Thank you!Thank you!

Please remember:

I will keep the material, examples and source code on the following address:

http://www.cs.utah.edu/~antunes/AJAX/

antunes@cs.utah.edu