Layin

Layin built to remove duplicate in your JSP pages. It is the simplest ever template framework you can see. (it consists only from 1 java source file).

Suppose you have a webapp of 5 JSP pages, each the same header, footer and a left pane.

You have 2 Option:

1. To have the 5 pages contains the HTML code for the header, footer and left page, and when you need to change the footer, you have to change in the 5 pages.
2. To use some template engine like freemarker, Apache Velocity or Apache tiles, but you need to face some learning curve, besides your webapp might be simple and you need to keep it simple.

####So what is the solution? The solution is Layin. That's it, Layin is the simplest ever template framework. All you need to know is very very simple rules, an all you will find in this readme page. see the next section "Usage".

Usage:

Three components the things you need to know about, the Filter, the Layout file(s) and your JSPs .

####The Filter Copy this Java Servlet Filter LayoutFilter.java to your Servlet-based webapp. (regardless of the web framework you use)

####The Layout file(s): It is a simple JSP page that contains the Header, Footer and navigation pane (or any other generic markup you use in your webapp)

You need to know about 4 request variables:

1. requestScope.title: Represents the page title.
2. requestScope.script:Represents the javascript code for JSP page.
3. requestScope.body: Represents the JSP page body contents.
4. requestScope.path: Has special use, as it should prepend any relative URL in the layout file.

See example here: Layout Example

You can have multiple Layout files as you like.

####JSP pages that uses the Layout It is the JSP pages that componse your app (like: Order.jsp, AddCustomer.jsp , etc ... )

1. Reference the layout file by setting attribute named layout_file in top of the JSP page.
2. Then you will have three sections

• @title contains the title of the JSP page.
• @script contains your javascirpts that need to have in your JSP: - Should include javascript in <script> tage. - In Javascript code, only comments that looks like /* ... */ is allowed. - Any Javascript statement should ends with a semi colon.
• @body contains the HTML body of your JSP page.

See example here: JSP page Example