executing portlet event phase without render phase - events

I need to cancel renderProcessing (doView method) from executing after processing Action or Event phase (As i don't want the whole page or any portlets to be refreshed). Something like ajax resource acquiring which is not leading to refresh all portlets (I mean serveResource method). Can we use "destroy()" method at the end of ProcessAction or ProcessEvent to prevent renderPhase from executing. I'm using MVCPortlet framework and events ipc extensively in my portlets. Thanks for your help.

As Georgy Gobozov stated in the comment: The answer to your question is "No".
If you are using the standard portlet request handling and rely on event handling, you're bound to a full page reload. There's nothing that keeps you from implementing custom event handling (e.g. with JS on the browser, through your business layer etc.) but unfortunately you'll have to do exactly this.
When you start the original request, e.g. through an action handler, the page has already started to reload (from the browser perspective). Any attempt to cancel the processing server side will result in the stream to break and the browser signalling an error on the page (e.g. "can't load": The result must come with an HTTP status - and it will most likely be an error code (e.g. 50x), or it must contain the whole page's HTML.

Related

Programmatically determine if Sagepay card details form is incomplete

I'm looking for some help with regards to the drop-in checkout integration.
https://developer-eu.elavon.com/docs/opayo/integrate-our-drop-checkout
In particular I'm following ‘custom flow’ example - see first code example for the Custom Flow section. https://developer-eu.elavon.com/docs/opayo/spec/api-reference#section/Custom-flow
In summary how can I programmatically determine if the sagepay 'card details' form which is injected into the sp-container (hosted in an iframe) is not valid for submission/tokenisation, when a call ‘tokenise’ link is used?
For example when the user has not completed all the required fields; Name, Card Number, Expiry or CVC.
I'm following the flow calling sagepayCheckout.tokenise() when the user clicks our 'Complete Payment' button (referred to as the tokenise link in the custom flow example).
NB: Implementation is part of a SPA app in my particular case I'm not submitting the (outer) form rather handling things using javascipt and calling the tokenise method.
Normally the onTokenise call back method is called on success or when wrong card details have been entered or merchantKey has expired. But when the injected sagepay form fails its own validity the onTokenise call back is never called.
NB: Due to browser security I can't check the state of the fields inside the iframe.
Ok some good points to note:
The sagepay form does feedback to the user about errors that required fields need to be completed.
And sagepayCheckout.tokenise() doesn't try to submit my (outer) form when these errors exist.
But there doesn't seem to be a programmatic way to know if the required fields need to be complete (or the onTokenise call back wont be called).
The main reason I need to know when the form is incompleted or tokenise has failed would be to re-enable our 'Complete Payment' button. Currently our button is disabled as soon as the user clicks it to prevent multiple clicks.
I am having this exact same problem. The only way I have been able to think of to get around this is to use the message event listener on the window. The sagepay.js library registers a 'message' event on the window object probably when the sagepayCheckout method is called.
Side note: this method is also poorly implemented as anything else that uses the window message event will cause the sagpay.js library to throw errors.
I think the only purpose of sagepay.js' message event hander is to resize the iframe window when its content changes. If you were to assume the content of the iframe will only change when validation fails you might be able use that to reset the state of your 'Complete Payment' button.
I would also suggest making a complaint to Opayo. This library is clunky and in desperate need of improvement.

Vaadin UI done or documentReady event

Is there any way to detect all Vaadin components, html, elements are loaded and rendered in UI. For devMode in browser console
... com.vaadin.client.communication.MessageHandler
INFO: Referenced paintables: ...
as info.
After this i want to push something to UI.
Vaadin version: 8.0.5, spring boot 1.5.2
There are two ways in Vaadin to update your UI asynchronously: polling and push. Basically, you initialize your application with the basic data and start the background threads that calculate additional data. Once calculation is done, you can update components accordingly and Vaadin will pull from client periodically (if you use polling) or push to client (if you use server push). Don't forget to wrap your calls with UI.access method when accessing components from the background thread.
Dirty workaround:
If you have a focusable component on your page you can abuse .addFocusListener() and .focus(). The focus event only fires after the focus was placed on the component and that's after the page is rendered.
Then off course set a flag that your event handler does not re-execute if the focus returns to the same component.

Kendo UI Grid/DataSource - Global Error Handling?

I've currently inherited an application which has numerous Kendo grids (and other controls) throughout, and I'm trying to fix an error which keeps cropping up now and again - specifically when the user is no longer authenticated.
I know what the solution is for a single instance of the control - return a flag to indicate authentication failed, and then detect this in the error handler and perform the authentication.
The problem is am I really going to have to handle this for every instance of a Kendo control I have? Is there not a global error handler I can hook into? Either for the data source itself (as I know this is used for all Kendo control data loading), or for the Grid specificially. I don't mind either way - just which one is a hook.
This would be a more straighforward short term solution than refactoring everything to specific error handlers, etc.
I assume you can attach a global error handler to $.ajax, which is used by the DataSource, you can check how to do it here:
http://api.jquery.com/category/ajax/global-ajax-event-handlers/
Or, you can take advanttage of that the configuration that is done in the DataSource is passed directly to the $.ajax:
http://docs.kendoui.com/api/framework/datasource#configuration-transport.read-ObjectStringFunction
For reference, someone from Telerik has provided a solution using just the DataSource. I haven't tested it, but I prefer the accepted answer above as it hooked into all Ajax on the site - not just ones that utilise the Kendo DataSource.
http://www.kendoui.com/forums/mvc/grid/global-error-handler-for-numerous-grids.aspx

Handling windows button during Async BeginGetResponse in wp7

is there any way to handle the Windows button keypress within the *.Xaml.cs especially when the app is busy getting a request processed using an Asynchronous BeginGetResponse. is there a override handler like OnBackKeyPress?
What's the appropriate way to handle this use case? i'm already handling Application_Activated and deactivated in the App.Xaml.cs file for tombstoning.
You can't stop this from happening. When this happens the current page will get its OnNavigatedFrom override called so you could clean up your page and save state from this method.
Bear in mind that it won't be possible to tell whether this is due to the hardware Start key or if the user just navigated away by say pressing the Back key or tapping a button.
Update:
If you're trying to avoid a crash due to Fast App Switching interrupting your networking call you should rather handle this when you return to the application. Your WebRequest will be cancelled and you should handle this case as shown in this MSDN blog post.

Best way to run a long DB query in classic ASP?

I have a couple of queries for a web site that take a long time to run due to the data model and the amount of data held in the tables. So far I've been running them manually against the database to avoid any timeout issues etc.. however the site owner has asked for these to be made available on the site so he can get the query results.
I had thought of doing this via a .NET web service and having the classic ASP page call this asynchronously. The web page would just initiate the process and before redirecting the user to another screen. The web service would then run the query and email the user the results in a CSV.
However, I can't seem to get this to work. The service runs ok if I invoke it through the screen in IE but calling it through an Ajax call in ASP seems to be an issue - no error is generated but neither is the CSV file created.
I've enclosed the classic ASP code below. The service only has one method with a parameter of the name email which is of the type string. Can anyone see anything wrong with it? Also, this the best way to be doing this or should I be thinking of another approach?
CODE
<%
message = "http://wwww.example.com/service/query.asmx/GetResults?email=test"
set req = server.createobject("MSXML2.XMLHTTP")
With req
.open "GET", message, False
.setRequestHeader "Content-Type", "text/xml"
.send
End With
works = req.responseText
response.redirect "http://www.bbc.co.uk"
%>
The idea of asynchronously requesting the work and arranging for its later delivery seems very reasonable to me. I don't speak ASP well enough to know what's wring with your attempt, but is that really an asnch call you have there? Would the seb service also suffer from an HTTP connection timeout?
My approach would have been for an Ajax request to place a request on a queue and return, no need for a redirect, you're still on the page where the user makes the request, your JavaScript could just acknowledge that the request was sent. Alternatively, your more traditional "submit a page, stash the request, display another page" appraoch can work, but the the stashing is just to put the request on a queue.
An advantage of the queueing approach is that by controlling the number of daemons we can get controlled parallelism in servicing the requests - avoid overloading the DB. Also the queues can persist and allow a leisurely delivery of the responses.
I assume that MS queues then let you have a daemon processing the reuquest and delivering the responses. Clearly email works, but strikes me as a tad unfriendly. With Ajax style interfaces it would be quite easy to invisibly poll for the status of requests and obtain the results when they are ready, or even to use Comet-style push delivery of the responses.
The problem here, as djna noted, is that you are not calling a callback function.
Due to the asynchronously aspect of Ajax, you have set up a callback function that will be executed when the Ajax call ends.
Long story short:
Call the webservice from a javascript function, preferably using JQuery to avoid cross browser incompatibilities
Code:
<div id="results">Processing query. Please wait</div>
<script type="text/javascript">
$(document).ready(function(){
$("#results").load("http://wwww.mywebsite.com/service/query.asmx/GetResults?email=test&Rnd=" + Math.random().toString());
});
</script>

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