I've been tasked with making a portlet on our landing page refresh, without refreshing the rest of the page, because it will probably kill our servers. If the whole page refreshed every time these settings would change. Buying new servers or optimizing our setup isn't an option at the moment.
If you change your portlet to a Resource Serving Portlet, you can then use the serveResource method and a resourceURL which doesn't refresh the page when called.
You'll also have to write a little JS to interact with the resourceURL via AJAX requests.
You can use the Serve Resource method for this purpose. Please note this feature is only available for JSR 286 Portlets. If you are still using JSR 168, this feature won't be available.
How to implement:
Add Serve resource URL of your portlet - Use OOB portlet tags.
The portlet can create resource URLs pointing back to itself in the following ways:
By invoking the createResourceURL() method of the RenderResponse object or ResourceResponse object
By using the resourceURL tag (for example, portlet:resourceURL)
When an end user invokes such a resource URL, the portlet container calls the serveResource() method of the portlet and renders the content returned by the serveResource call. You can also set a resource ID of the resource URL to enable the same serveResource() to serve multiple resources.
The serveResource method can also be used to implement Ajax use cases by invoking the resource URL through the XMLHttpRequest(or XMLPortletRequest) in client-side JavaScript code. The client-side code of the portlet can be refreshed thru AJAX call.
Related
I want to 301 redirect the URLs from previous site that are nested, as pencilblue doesn’t support them,
e.g. a/b to page/b
For this I have been experimenting in include/http/request_handler.js but facing some issues.
Call never comes inside RequestHandler.prototype.handleRequest or even RequestHandler.prototype.onSessionRetrieved (seems these methods are not being called from anywhere)
Therefore I placed the code in RequestHandler and after confirming that req is not for public resource or api, I create a new url and execute
return this.doRedirect(newUrl, 301)
This actually works but at the same time I receive
Can’t render headers after they are sent error
#1075 has not helped me much as I’m not sure which specific controller I should modify. I need to catch the req as early as possible and see if it’s a page then redirect to page prefixed url.
Thanks in advance.
There are couple of ways to do redirects. You can do them from a controller or from middleware. You are correct in that, some of the functions in the request handler are not called. These are deprecated despite the fact pencilblue team didn't mark them as such. They replaced a good deal of the request handler functionality with /include/http/router.js and include/http/middleware/index.js. Plugins can register their own middleware to hijack the request pipeline.
See Advanced Routing on wiki for more info about creating your own middleware.
Using the routing framework your plugin would be able to register middleware that would be able to inspect the request and then redirect based on your specific criteria. The Router will be accessible from req.router and from there you could call req.router.redirect (Source).
Reference: #1224
We are using form-based auth in our GWT application and I'm currently struggling a lot with session timeout.
If the user is logged in and performs an action that will trigger a request for a static resource AFTER the session has timed out, then the login page is shown and when the user logs in again, then only the image resource is shown to the user. An example is if the user hovers the mouse over a button, and the button need to fetch a icon which is shown on mouse over.
It is logical that this will happen, since the login page was triggered by the request for the image, but it is not really the behavior that we want. It would much better that the user is redirected to the page he was on, or alternatively another page.
How can this be handled in a better way? As I understand it is very difficult to change the redirect url, which j_security_check uses to redirect the user after successful login.
The way I solve it is to only protect the HTML host page with a <security-constraint>. Static resources (images, stylesheets, GWT scripts) aren't protected at all, and AJAX endpoints (GWT-RPC, RequestFactoryServlet, or other endpoints called using AJAX from the app) only check the presence of a user Principal in the request (this can be done in a servlet filter, or a RequestFactory ServiceLayerDecorator), and return an error otherwise (but do not trigger the login page).
You can see an example web.xml here with the code to handle the security in RequestFactory here (and the code to handle the response on the client-side here). For GWT-RPC, you'd probably do that using a servlet filter and a custom RpcRequestBuilder or a base AsyncCallback<?> implementation.
I'm using GWT to develop a web app. I'm currently using AJAX calls to retrieve values from the server. I have following queries regarding to AJAX calls:
Assume: I have an app, name of which is: "Application" and the entry point class is: "entry.java"
I know: the application could be invoked as: http://localhost:8080/Application/entry.html
1. I would like to know what what is the output URL given by gwt.getmodulebaseURL()?
Assume: In the same application I have a service called "ServerValuesService" and its corresponding Async. I have corresponding serviceImpl, which has a method called List < String >search(String) at the server side.
I could retrieve the values from the server as well. However,
2. I would like to know what would be the direct URL to access this service? For Instance, I need to obtain the list of values, by just giving a URL (passing value for the String). i.e. I need to access the method search(String) and retrieve the list just by typing a url such as:
http://localhost:8080/Application/entry/serverValuesService?string="hello"
I'm sure the above URL is wrong. I need to know exact conversion between URL and the corresponding service. Is this possible at all?
Thanks in advance!
1) In your case it will give you http://localhost:8080/Application . Application is your modulename.
2) These services are actually HttpServlets and their URL's are defined in the web.xml file. But Google uses POST method to send your variables and takes care of serialization for you, what you are trying to do is send it via GET method which is as far as I know not implemented by Google RemoteServiceServlet.So I would say no its not possible unless you extend these services to work with GET methods yourself but I don't know if that is possible.
Assume: I have an app, name of which is: "Application" and the entry point class is: "entry.java"
I know: the application could be invoked as: http://localhost:8080/Application/entry.html
The url http://localhost:8080/Application/entry.html is called host page url. In this html page you load your GWT module using a script tag:
<!-- This script tag is what actually loads the GWT module. The -->
<!-- 'nocache.js' file (also called a "selection script") is -->
<!-- produced by the GWT compiler in the module output directory -->
<!-- or generated automatically in hosted mode. -->
<script language="javascript" src="calendar/calendar.nocache.js"></script>
So if you put above example in your entry.html, the module will be loaded from http://localhost:8080/Application/calendar/calendar.nocache.js making http://localhost:8080/Application/calendar/ your module base url.
I would like to know what would be the direct URL to access this
service? For Instance, I need to obtain the list of values, by just
giving a URL (passing value for the String). i.e. I need to access the
method search(String) and retrieve the list just by typing a url
GWT RPC use a custom serialization format to encode requests to the RPC Service on server. The RPC service is implemented as a subclass of RemoteServiceServlet on the server. The RemoteServiceServlet handles the http POST requests, de-serializing the request from client and invvoking appropriate service method of sub-class.
So for directly accessing the service you'll need:
1. The service URL
2. Request payload encoded in GWT's custom serialization format
3. Ability to HTTP POST the payload to the Service URL
1 and 3 are easy to acquire. You already know the URL at which your service is mapped in web.xml. And you can do post from any http client or browser plugins like this. The hard-part would be to generate request payload in GWT's custom serialization format. For simple cases, you can generate a request from your application and capture the raw payload from Firebug, Fiddler or similar tool and simply replay it using your http client.
I have a web service in the form `http://....../methodName
It returns a jsonp result such as:
methodName(["a":"a", "b":"b"])
GWT provides JsonpRequestBuilder class to parse jsonp.
JsonpRequestBuilder rb = new JsonpRequestBuilder();
rb.setCallbackParam("callback");
rb.requestObject("http://...../methodName", new AsyncCallback<TestJS>(){
...
});
This structure makes a request to url :
"http://...../methodName/?callback=__gwt_jsonp_P0.onSuccess".
My web service returns a callback with methodName not with __gwt_json.....
So gwt could not create a JavaScriptObject from that response.
Also JsonpRequestBuilder works with GET not POST.
How can I achieve those: Sending requests with POST and modifying GWT's default callback name.
JSONP will NOT work with POST. Its not a GWT limitation btw.
JSONP is essentially including a javascript file from your server. So, when you make a JSONP call, a temporary tag is added to the DOM.
Now, a <script> tag can always makes a GET request. That's a browser thing, and GWT cannot do much about it.
If you want to make a cross-domain POST call, you have to chose from one of the following options (and they have nothing to do with GWT)
Use Flash plus a crossdomain.xml that allows cross domain posts
Use Cross Origin Resource Sharing, or CORS. NOTE that this is only supported in modern browsers
Use a proxy server on your domain
Unfortunatly, this isn't how JsonP works. The requests are made by adding a tag to the page, and the results are passed into a function wrapped around the data – in your case, __gwt_jsonp_P0.onSuccess.
The callback name can't be affected, at least while using JsonpRequestBuilder – the system needs to account for the fact that you could send multiple requests out at once, possibly even to different endpoints. A JsonP endpoint that doesn't allow the caller to customize the callback function name is very unusual, and even more odd is an endpoint expecting JsonP calls that expects an impossible POST.
You can implement your own JsonP client side code by using the ScriptElement type, and registering your own global callback to call into your GWT java code.
Look into the API docs for the web service, and see if there is perhaps a better way to communicate with it, perhaps by using a proxy on your own server, avoiding the cross domain issue altogether.
Is there a way to go to a url without redirecting to it? Basically I want to call a url from within my application in the background so it can logout a reliant party.
Appreciate the help.
What you are trying to do does not compete us to answer as it's directly related to your own Authentication implementation.
A normal ASP.NET Authentication based in Forms Authentication you will need always to lunch the url from a browser as it is there that relies the Authentication given.
You can give yourself a try by opening your website and log in into it, after that, open other browser brand (not browser window) into your application url... you will see that you also need to login again as the Authentication is hook up into the first browser.
It's Up to you as Application Architect to make this by implementing another way of authentication, normally in this kind'a cases, this happend when consuming web services where you need a authentication code first (given by calling a Login method) and that code is always needed to be appended to the body or header of any call to the system.
This way you can easily remove the authentication code and all procedure calls will fail.
As said, this is not up to us, it's up to you to create the correct Authentication Layer.
from your comment
it's as simple as using WebClient object
WebClient client = new WebClient ();
string reply = client.DownloadString (address);
If you wish to transfer to a new url request you can still use
Server.TransferRequest()
The problem with this is that by not using a redirect the browsers address bar will not reflect the fact that you have moved their request to another URL.
To have the client visit a given URL in the background you should either make an AJAX call to it or possibly have an image with an src of your logout url (though you'd have to make sure that you return a FileResult of your image too). This is how most analytics packages call to their relevant urls in the background.
The problem here though is that neither is 100% reliable, turn off javascript or images on your browser and these results fail.
From what you've said I think what you're after is for a user to continue to any of a variety of pages rather than a specific logout page. If this is indeed the case your best solution is in fact a double redirect.
Have your application redirect to your logout url but before hand put the url of the page you want them to go to into tempdata. Then in the actionresult for the logout page you can do your logging out as required and return a redirect to the url from tempdata.