JSP, can it work similar to yield, layout, content_for in Ruby/Rails/Erb_问答_开发者

JSP, can it work similar to yield, layout, content_for in Ruby/Rails/Erb

开发者 https://www.devze.com 2023-01-28 11:49 出处：网络

I am trying to figure out how to most effectively reuse JSP code. I love the way Rails/erb works in that way ... with yield, layout, content_for

Example:

main_layout.erb.html

<html>
  <head><%= yield :head %></head>
  <body><%= yield %></body>
</html>

use

<% content_for :head do %>
<title>A simple page</title>
<% end %>

<p>Hello, Ra开发者_开发技巧ils!</p>

in controller

layout "main_layout"

What is the closest I can get to this with JSP (without using extra frameworks)? I know about JSP include but that's not really the same as yield. Any suggestions?

Thanks

I'm not familiar with what yield and content_for provide, but JSP tag files allow you a more robust way to template pages than JSP includes.

Example:

layout.tag

<%@ tag body-content="scriptless" %>
<%@ attribute name="pageTitle" required="true" type="java.lang.String" %>

<html>
<head>
    <title>${pageTitle}</title>
</head>
<body>
    <jsp:doBody/>
</body>
</html>

An individual JSP

<%@ taglib prefix="z" tagdir="/WEB-INF/tags" %>
<z:layout pageTitle="A simple page">
    <p>Hello, JSP!</p>
</z:layout>

Just place your layout.tag in the /WEB-INF/tags directory. You can use any available prefix you want, I just used "z" for the example.

While you mentioned wanting no frameworks on top of stock jsp, the Layout functionality of the Stripes Framework does pretty much exactly what you're asking for.