====== MVC ======

This lecture covers the MVC design pattern for web applications in the context of a mini-project. This includes writing servlets to control and dispatch, models to model the data and the business rules, and JSP pages to author the view.

===== Outline =====

  * The controller must control and dispatch by relying on the Model and forwarding to a JSP
  * Tomcat provides three ''Map<String,Object>'' places to hold data with three levels of scope: request, session, and application.
  * State can be captured using the session object. Its API allows us to detect the start of new sessions.
  * The model is best packaged as a Java package.
  * The model uses beans and POJOs. It is compiled (using ''javac'') and tested outside Tomcat.
  * The servlet's ''init'' method is responsible for instantiating the model and storing it in the application scope.
  * Jasper translates a JSP page to a servlet upon receiving the first reference to it (typically from a servlet forward).
  * Jasper allows us to embed three things in the JSP page in addition to template (e.g. HTML) code: Expression Language EL, Directives, and Actions. These will be evaluated by Jasper and their values are served as part of the response.
  * EL uses a number of built-in, implicit objects.
  * Actions are either standard (JSTL) or custom.




===== To Do =====

  * Read the rest of Chapter 6.
  * Read Chapter 8 up to Section 8.4.1 but omit 8.3.2-8.3.3.
  * Look at ''ELdemo.jspx'' and ''JSTLdemo.jspx'' in the //Resource Directory//.
  * Do [[http://www.cse.yorku.ca/~roumani/warp/labs/lab4.htm|Lab-4]].

===== Slides from Lecture =====

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