Ajax + Tiles issues

[Eddy Dean]

I can't seem to get AJAX working properly with spring-js and tiles. I have created a small sample project with only two pages ("home" and "about us"), and I tried to let it reload only the contents of the page when a link is clicked, instead of the entire page.

While displaying the pages by typing the URLs in the address bar of the browser works just fine, clicking the ajax links does not. Appending ?fragments=content to the url seems to get ignored by the application, it has no influence on page rendering. When an ajax link is clicked an error page sort of "pops up" (gets overlayed on the browser window, I blame dojo). The error page shows the following trace:

exception 

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:583)
	org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:501)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)

root cause 

java.lang.NullPointerException
	org.springframework.js.ajax.tiles2.AjaxTilesView.renderMergedOutputModel(AjaxTilesView.java:92)
	org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:257)
	org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1183)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:902)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:807)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:571)
	org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:501)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)

I'm using the most recent version of Spring (2.5.6), Spring Web Flow (2.0.7) and Tiles (2.1.2).

The code of the project is below. I tried to keep it as small as possible.

dispatcher-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:flow="http://www.springframework.org/schema/webflow-config"
       xmlns:sec="http://www.springframework.org/schema/security"
       xsi:schemaLocation="
           http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/webflow-config
           http://www.springframework.org/schema/webflow-config/spring-webflow-config-2.0.xsd">

  <bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
    <property name="basename" value="/WEB-INF/classes/messages"/>
    <property name="cacheSeconds" value="60"/>
    <property name="defaultEncoding" value="UTF-8"/>
  </bean>

  <bean id="tilesViewResolver" class="org.springframework.js.ajax.AjaxUrlBasedViewResolver">
    <property name="viewClass" value="org.springframework.webflow.mvc.view.FlowAjaxTilesView"/>
  </bean>

  <bean id="tilesConfigurer" class="tool.SpringTilesConfigurer">
    <property name="definitions">
      <list>
        <value>/WEB-INF/tiles-layout.xml</value>
      </list>
    </property>
  </bean> 

  <bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
    <property name="mappings">
      <value>
                /**/home.htm=homeController
                /**/about.htm=aboutController
      </value>
    </property>
  </bean>

  <bean id="homeController" class="tool.RegularController">
    <property name="viewName" value="home"/>
    <property name="titleKey" value="homepage.title"/>
  </bean>
  <bean id="aboutController" class="tool.RegularController">
    <property name="viewName" value="about"/>
    <property name="titleKey" value="aboutpage.title"/>
  </bean>
</beans>

tiles-layout.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE tiles-definitions PUBLIC
  "-//Apache Software Foundation//DTD Tiles Configuration 2.0//EN"
  "http://tiles.apache.org/dtds/tiles-config_2_0.dtd">

<tiles-definitions>
  <definition name="home" template="/WEB-INF/views/regularroot.jsp">
    <put-attribute name="content" value="home.content"/>
  </definition>

  <definition name="home.content" template="/WEB-INF/views/home.jsp">
  </definition>

  <definition name="about" template="/WEB-INF/views/regularroot.jsp">
    <put-attribute name="content" value="about.content"/>
  </definition>

  <definition name="about.content" template="/WEB-INF/views/about.jsp">
  </definition>
</tiles-definitions>

views.properties

home.class=org.springframework.web.servlet.view.tiles2.TilesView
home.url=home

about.class=org.springframework.web.servlet.view.tiles2.TilesView
about.url=about

regularroot.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jstl/core_rt"%>
<%@taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<%@taglib prefix="tiles" uri="http://tiles.apache.org/tags-tiles"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <script type="text/javascript" src="<c:url value="/resources/dojo/dojo.js" />"> </script>
    <script type="text/javascript" src="<c:url value="/resources/spring/Spring.js" />"> </script>
    <script type="text/javascript" src="<c:url value="/resources/spring/Spring-Dojo.js" />"> </script>
    <title>
      <c:out value="${titleKey}"/>
    </title>
  </head>
  <body>
    <h1><c:out value="${titleKey}"/></h1>
    <ul id="menu">
      <li>
        <a href="<c:url value="home.htm"/>" id="home">Home</a>
      </li>
      <li>
        <a href="<c:url value="about.htm"/>" id="about">About us</a>
      </li>
      <script type="text/javascript">
        Spring.addDecoration(new Spring.AjaxEventDecoration({
          elementId: "about",
          event: "onclick",
          params: { fragments:"content" }
        }));
        Spring.addDecoration(new Spring.AjaxEventDecoration({
          elementId: "home",
          event: "onclick",
          params: { fragments:"content" }
        }));
      </script>
    </ul>
    <div id="content">
      <tiles:insertAttribute name="content"/>
    </div>
  </body>
</html>

I also think the documentation for using ajax with spring could be improved. Also the documentation for spring-js is almost non-existent.


Thanks in advance,

Eddy Dean


---- EDIT ----

I've been reading through the source of org.springframework.js.ajax.tiles2.AjaxTilesView, and it seems that it uses quite a lot deprecated methods, which causes the NullPointerException. The problem seems to be that BasicTilesContainer.getContextFactory is deprecated and always returns null.

[jpreston]

Eddy Dean,

Be it far from me to say what to use, but there have been many discussions regarding the usage of Spring 2.5.x and Tiles 2.1.x. The general consensus leads to ultimately two conclusions:

1. Writing a new Tiles Configurer for Tiles 2.1.x and Spring 2.5.x
2. Downgrading Tiles to 2.0.x until Spring 3.0.x is stable

It appears that you've done the first option, so I'll let that be a decision for you. I've run into a similar problem, though it was a couple months ago, and I seem to remember having to add the requestContextAttribute property to my viewResolver to clear it up. Although it might not help, it's at least a suggestion.

For yours, it might look something like:

  <bean id="tilesViewResolver" class="org.springframework.js.ajax.AjaxUrlBasedViewResolver">
    <property name="viewClass" value="org.springframework.webflow.mvc.view.FlowAjaxTilesView"/>
    <property name="requestContextAttribute" value="requestContext" />
  </bean>

Hope that helps,

[eggsy84]

Hi there,

Has anyone got any further with this?

I am getting the same error when using Spring 3, Spring Web Flow 2.0.8Release and Tiles 2.1.3

Eggsy

[eggsy84]

I have noticed the JIRA ticket which includes a view resolver that fixes the issue but has there not been any further action on this?

JIRA Ticket URL:
https://jira.springsource.org/browse...mment-tabpanel

Eggsy