Fluxion AJAX Spring Integration libraries

To start building AJAX-enabled beans, simply include the fluxion-ajax module artifact in your dependency section of your bean project pom.xml. This will suck in all the other required dependencies:

<dependencies>

...

  <dependency>
    <groupId>net.sourceforge.fluxion.ajax</groupId>
    <artifactId>fluxion-ajax</artifactId>
    <version>1.0-SNAPSHOT</version>
  </dependency>
  
...

</dependencies>

You can then start writing your bean.

Imports

Firstly, a few simple imports need to be present in each bean:

package your.bean.package;

import net.sf.json.JSONObject;
import net.sf.json.JSONException;
import javax.servlet.http.HttpSession;

import net.sourceforge.fluxion.ajax.Ajaxified;
import net.sourceforge.fluxion.ajax.util.JSONUtils;

The @Ajaxified annotation

Secondly, each bean needs to be annotated by the @Ajaxified annotation. This is picked up at runtime and allows the Spring system to expose these beans and allow them to be handled by a class called the AjaxExporter (see the Documentation pages).

@Ajaxified
public class AjaxTestBean { ... }

Method signature

Finally, each bean method will be exported by the underlying AjaxHandler system (see the Documentation pages) so that it's callable by name from the Fluxion AJAX Javascript library functions. Each method has to follow a certain signature whereby the parameters are:

  • the current HTTPSession so that any session parameters are available to the method
  • and a JSONObject that represents the serverParams object passed via AJAX to the bean (see the Fluxion AJAX Javascript library pages)
public JSONObject test(HttpSession session, JSONObject json) throws JSONException { ... }

Building responses

The JSONUtils helper class contains some convenience methods for constructing simple AJAX responses. More information on these methods can be found in the fluxion-ajax API.

Simple responses with JSONUtils.SimpleJSONResponse

Putting this all together, here's an example bean that just returns a hardcoded response back to the client:

package net.sourceforge.fluxion.beans;

import net.sf.json.JSONObject;
import net.sf.json.JSONException;
import javax.servlet.http.HttpSession;

import net.sourceforge.fluxion.ajax.Ajaxified;
import net.sourceforge.fluxion.ajax.util.JSONUtils;

/**
 * A test version of an ajaxified bean
 *
 * @author Rob Davey
 * @date Jan 21st 2010
 */
@Ajaxified
public class AjaxTestBean {
  public JSONObject test(HttpSession session, JSONObject json) throws JSONException {
    return JSONUtils.SimpleJSONResponse("Here is a simple JSON response");
  }
}

Error responses with JSONUtils.SimpleJSONError

You can also return error messages that will be popped up as a Javascript alert by the client:

@Ajaxified
public class AjaxTestBean {
  public JSONObject test(HttpSession session, JSONObject json) throws JSONException {
    String os = System.getProperty("os.name").toLowerCase();
    if (os.indexOf("win") >= 0) {
        return JSONUtils.SimpleJSONError("I am running on Windows :(");
    }
    return JSONUtils.SimpleJSONResponse("I'm not running on Windows :)");
  }
}

More complex responses with JSONUtils.JSONObjectResponse

Returning more complex responses with custom JSON objects or arrays is also easy using a JSON string:

@Ajaxified
public class AjaxTestBean {
  public JSONObject test(HttpSession session, JSONObject json) throws JSONException {
    return JSONUtils.JSONObjectResponse("{'isFinished':'false','isStarted':'true'}");
  }
}

Or with a vararg of JSONObjects:

@Ajaxified
public class AjaxTestBean {
  public JSONObject test(HttpSession session, JSONObject json) throws JSONException {
    return JSONUtils.JSONObjectResponse(
        JSONObject.fromObject("{'foo':'1'}"),
        JSONObject.fromObject("{'bar':'2'}"),
        JSONObject.fromObject("{'baz':'3'}")
    );
  }
}

Finally...

You need to tell the AjaxExporter which beans you are going to allowed to be checked for @Ajaxified status, and this is done simply by adding in the bean declaration in a special ajax.xml config file within your project. If you have multiple projects housing Ajaxified beans, and hence multiple ajax.xml config files, this is automatically handled for you by the AjaxExporter.

So, simply create src/main/resources/fluxion/ajax.xml within your project and declare your beans as you would normally in Spring:

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

  <bean id="ajaxTestBean"
        class="net.sourceforge.fluxion.beans.AjaxTestBean" />
        
</beans>
 
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