Retrieve the fragment (hash) from a URL and inject the values into the bean

Question 1

Retrieve the fragment (hash) from a URL and inject the values into the bean

java javascript jsf facelets fragment-identifier

Choesang · Aug 13, 2010 · Viewed 12.4k times · Source

Answer

Answer

You can do this with help of window.onhashchange which fills an input field of a hidden form which submits itself asynchronously when the input field has changed.

Here's a kickoff example of the Facelets page:

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" 
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:h="http://java.sun.com/jsf/html">
    <h:head>
        <title>SO question 3475076</title>
        <script>
            window.onload = window.onhashchange = function() {
                var fragment = document.getElementById("processFragment:fragment");
                fragment.value = window.location.hash;
                fragment.onchange();
            }
        </script>
        <style>.hide { display: none; }</style>
    </h:head>
    <h:body>
        <h:form id="processFragment" class="hide">
            <h:inputText id="fragment" value="#{bean.fragment}">
                <f:ajax event="change" execute="@form" listener="#{bean.processFragment}" render=":showFragment" />
            </h:inputText>
        </h:form>
        <p>Change the fragment in the URL. Either manually or by those links:
            <a href="#foo">foo</a>, <a href="#bar">bar</a>, <a href="#baz">baz</a>
        </p>
        <p>Fragment is currently: <h:outputText id="showFragment" value="#{bean.fragment}" /></p>
    </h:body>
</html>

Here's how the appropriate bean look like:

package com.stackoverflow.q3475076;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.event.AjaxBehaviorEvent;

@ManagedBean
@RequestScoped
public class Bean {

    private String fragment;

    public void processFragment(AjaxBehaviorEvent event) {
        // Do your thing here. This example is just printing to stdout.
        System.out.println("Process fragment: " + fragment);
    }

    public String getFragment() {
        return fragment;
    }

    public void setFragment(String fragment) {
        this.fragment = fragment;
    }

}

That's all.

Note that the onhashchange event is relatively new and not supported by the older browsers. In absence of the browser support (undefinied and so on), you'd like to check window.location.hash at intervals using setInterval() instead. The above code example should at least give a good kickoff. It works at at least FF3.6 and IE8.

Question 2

I am looking for a way to inject values from the fragment (#) of a URL into bean(JSF), in the same way query-parameter values are injected. I am using Ben Alman's Bookmarkable jQuery plugin (http://benalman.com/projects/jquery-bbq-plugin/) to create the URL fragments. I was hoping that Custom regex patterns from prettyFaces could be a way to solve my problem but until now I have been unsuccessful.

(http://ocpsoft.com/docs/prettyfaces/snapshot/en-US/html_single/#config.pathparams.regext)

I would like to define here my situation and if any one has an idea, i would love to try them out.

I am using
RichFaces: 3.3.3,
Spring: 3.0.2.RELEASE,
Hibernate: 3.5.3-Final,
JSF: 2.0.2-FCS,
PrettyFaces: 3.0.1

The web application generates, following kind of URL where parameters are listed after a hash(#). The idea is to have an ajax based Bookmarkable URL. So every time I click on an element that changes the state of the system, the value is sent to the server via ajax and the URL after the hash is rewritten. There can be 1 to 3 parameters after the hash, the number of parameters are optional.

My goal is, when the user bookmarks the URL (with hash) and than revisits the saved page, the page should inject the correct values into the system and visualize the page in the previous state (like query-parameter).

Below, I have a regular expression that would catch all the parameters after the hash.

//URL:   
http://localhost:8080/nymphaea/workspace/#node=b48dd073-145c-4eb6-9ae0-e1d8ba90303c&lod=75e63fcd-f94a-49f5-b0a7-69f34d4e63d7&ln=en

//Regular Expression:    
\#(\w*\=(\w{8}-\w{4}-\w{4}-\w{4}-\w{12}))|\&(\w*\=(\w{8}-\w{4}-\w{4}-\w{4}-\w{12}))|\&(\w*\=\w{2})

I know there are websites that some how send the URL fragment into there server side logic,

Is there anyway to inject values from the URL fragments into server side beans?

Retrieve the fragment (hash) from a URL and inject the values into the bean

Answer

Related questions