I have a method in action page, it will take more time to execute so I have write some description on console window. But now i want to show the description on text area in jsp page. how to show like as console.
Two possible solutions are the "execAndWait" interceptor and using ajax.
Execute and Wait will be the easier to implement but will present less functionality...
http://struts.apache.org/2.3.4.1/docs/execute-and-wait-interceptor.html
Ajax can provide continuous feedback of the state of the request (although managing that feedback is entirely up to you and it will typically require you to think in terms of services, one page will typically make use of multiple services).
For this you will not have to worry about the amount of time it takes your action to return because it is being called asynchronously. You could even make a queue showing how many request you've sent and pop them off as they are received.
To implement ajax services it is easiest to start with json and for that see the struts2-json-plugin http://struts.apache.org/2.2.3/docs/json-plugin.html
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I am wondering if there is a way to trigger message box on server side.
My case is that I have some logic on server side of the scout application. In the middle of the process some decision need to be made. It this case I would like to trigger message box with YES, NO, CANCEL options.
The way my logic works it really hard to split it into two functions and call one first, ask question and call another with on answer. So this is out of the way for me.
If it is not possible to triggered message box on scout service, is there a way to "mimic" it. So call service method, in the middle pause it, go to client side, present messsage box, return to same service method and continue it.
Why do I need this:
I have dependencies graph (between fields) implemented on scout server side.
After one field has been changed, the whole dependencies graph will be resolved.
One node of the graph has some logic that need user interaction. Problem is that I don't know if this method will be called (dependent on a graph), and if after this method other nods will be called.
You have asked a very similar question few months ago:
Scout Eclipse present optional message on server side
MessageBox is a client concept (package is: org.eclipse.scout.rt.client.ui.messagebox).
You need to transfert the data you need from the server to the client and intercept this information client-side to display the message box you want.
As Jmini already said, MessageBox is a client concept. What you can do is sending back a status (from server to client), checking it on client side and show an appropriate message (box). But then you interrupt your service method and cannot go on where it stopped (alternatively you can throw a VetoException, but this interrupts your service method aswell, so same problem). In my opinion, it is also not a good design to 'request' a user interaction from server side, because in this case, the server side has to wait for the user to respond.
I suggest, if possible, to split your logic into different parts. At first, you execute the first part until you reach the point where you need the user interaction. Then you could save the current state of execution, return to client and show the message. After the user has responded, you should start the 'second' execution, depending on the user's input. This second execution should be started by calling another (new) service, which at first should load or restore the state of the execution saved before requesting the user input.
I have a little issue with a form in a delphy XE2 application:
It's an old issue on this application and i have begin to work on it just since a little time.
When the user choose to launch the process with a button's event, my application launch a connexion with an OPCServer , an SQLServer and construct the form for a good following of data take on the tow servers.
The construction of my form involves a blockage of the interface (for approximately 15 sec) because of lot's of data which are necessary for make it.
When it freeze, if the user want drag the form, she go far away, and usually with the TMainMenu which go out of the screen. After that, it's impossible to use the application because we can't drag and we need to close and re-open.
In the old version, the form be already construct before the connexion. So the modification for a dynamic form isn't in link with this issue.
Life of my event :
-Open connexion with OPC Server
-Open SQL Connexion
-Send SQL Command Text
-FieldByName('') for update my UI (Button.Caption// TPage.TStaticText.Caption // TPage.Label1.Caption)
-FieldByName('') for update an array of record
-Close SQL Connexion
-Open SQL Connexion
-Send SQL CommandText
-FieldByName('') for update an other array of record
-Panel.Visible(false)
-TPage.Panel.Show;
-TPage.Panel.BringToFront;
So I haven't MainForm modification can change its position.
I'm a young developer, so I don't know why it moving and what I can make for repair that...
If you want a part of code, ask me what and i edit this, it's very long and i don't want spam answer.
Thank's for read.
The core of your problem is that you have a lengthy process (form construction) which completely blocks the main thread so your application isn't able to process normal Windows messages at the same time. That is why when you move your application it doesn't properly update its interface.
Now based on your description you already have this form construction process split into multiple steps so you could call Application.ProcessMessages between them.
This will force your application to update its UI part.
But beware calling Application.ProcessMessages often could hurt your application performance quite a bit. Why? It is usually a lengthy process because it forces your application to process all the messages that are in its queue.
Normally not all of these messages get processed as soon as they arrive. Windows groups them in the message queue by their priority list, making sure that high priority messages like WM_PAINT are processed as soon as possible while some other low priority messages like demand for application to respond to OS so that OS can see if the application is still working are mostly processed when application is idle or when they are in queue for certain amount of time.
So that is why Application.ProcessMessages can be so slow as it forces your application to process all messages regardless of their priority.
Also bear in mind that using Application.ProcessMessages can in certain scenarios actually become a bit dangerous.
Let me give you an example:
Lets say that clicking on a button starts a lengthy job which can take some time to finish. Now in order to allow your form to be updated you call Application.ProcessMessages in certain intervals. So far it is all good. But what happens if user clicks on that button again?
Since you are calling Application.ProcessMessages which forces your application to process all the messages and since clicking on button creates a MouseClick message which then fires buttons OnClick event which then executes the OnClick method that has been assigned to buttons OnClick event in the end this will cause the same method that was executed on first button click to be executed again.
So now you have this method partially done from first button click and same method executing again for second mouse click. Now the method that was executed from the second click will finish first and then the method that was started from first button click but was interrupted with Application.ProcessMessages handling the second button click will continue its execution to the end.
This all can lead to strange bugs which are hard to track, because you as a programmer normally don't predict that your end user might have clicked the button twice.
So to avoid this I strongly recommend you implement some safeguard mechanisms to prevent such scenarios by temporarily disabling a button for instance.
But the best solution is always to show your user that your application is working which in most cases will dissuade them from clicking the button again, but unfortunately not always.
You should also take a good care when dynamically constructing a form to enable the controls only after all of the controls have been successfully constructed. Failing to do so the user might click on one of your controls and that control could attempt to access some other control which hasn't yet been created at the time. The result hard to track bug which causes Access Violation.
You might also consider showing a splash screen at start instead of half built form. Why?
For once it is much nicer to see and it tells your users to wait a bit. And for second having main form hidden until it is fully created makes sure that user won't be doing any clicks on it prematurely.
How does the notification area on Facebook works?
I'm taking about the automatically red box that appears.
If I have a message/something new on my wall.
I believe it is also in Stack Exchange, is that a Javascript interval?
Please see this thread
How does one do realtime updates of a web page?
Not sure about this, but I'd wager that both Facebook and SO use an implementation of Comet. Basically, you make a request to the server which is designed to be kept open a really long time, and the server only responds when it has something to say. When the request times out (or receives data back) you simply start up another one. This way you get as close to real-time data as you can without wasting a ton of bandwidth on empty requests.
Did anyone hear about asynchronous executing of an EF query?
I want my items control to be filled right when the form loads and the user should be able to view the list while the rest of the items are still being loaded.
Maybe by auto-splitting the execution in bulks of items (i.e. few queries for each execution) all in same connection.
I posted a feature suggestion to Microsoft, please share them with your ideas as well.
Not wanting to sound like a commercial, but I noticed that the latest DevExpress grid gives features like this in their WPF grid. Essentially you want to load visible-count items first, then load the rest in a background thread so your UI isn't freezing up. The background thread should probably load another page at a time and make them available to the UI thread.
It's something you would want to think about carefully and make sure you get it right, or simply buy a control that does the hard work for you.
I take from your link that this is a web app. Is that correct?
A Query must complete and return data before rendering can begin. An EF feature will not help you here. Rather. look at breaking up your process into several processes that can be done at once.
Keep in mind that ASP.NET cannot return a response to a browser if it is not done rendering the HTML.
Let me assume you are executing a single query, getting the results back and displaying them to a page.
Best option: Page your results. if you Have 4000 records, show the first 50. If you show 200+ records to a user, They cannot digest that much information.
If that does not fit your needs, look at firing one query for 50 results. Make an Ajax call to the the remaining records and build the UI from there, in (reasonably sized) chunks.
I'd like to integrate something like a welcome panel (welcome screen) into our iPhone application to inform our users about updates and new offers when they launch the application. I have the following thoughts and doubts:
No user input required
Shows generic HTML without any action from the user point of view, the thing closes after 2 or 3 secs and has a close button if you want to close it manually. This is for advertising and tips.
This should be very simple to implement
User input required
Shows generic HTML with an action required from the user point of view, for example a survey. The user should be able to skip it
same as above, but is it possible that the user submits something on a HTML page and that causes also something to happen within the iPhone app (maybe via Java Script)? For example the user submits a survey on the HTML page and then app closes the current screen and continues to the next screen (i.e. the real application)?
Is it also possible to receive parameters (e.g. an ID) via a HTML website? e.g. if the user receives an offer on the HTML welcome panel, then he clicks on it and it takes him directly to a screen in the iPhone app with content loaded from a server (via JSON) depening on the offer id retrieved through the HTML page.
We prefer implementing it via HTML, because it gives us more flexibility. But I'm also open to hear other suggestions.
Thanks
Rengers answer is the correct one to accomplish what you want. However, the real correct answer is "Don't do that in the first place."
From a design perspective, a "Welcome Panel" or any kind of startup/splash-screen is a bad idea and the Apple Documentation tells you explicitly not to use them. Even for games, they're a bad idea that should be avoided if possible.
It's not a "Welcome Panel" it's a "wade-through-all-our-marketing-crap-before-you-can-actually-use-our-app" panel.
Mobile apps aren't like apps for regular platforms. Non-mobile hardware is faster so the obtrusive startup screens load faster and can be dismissed faster. Non-mobile apps tend to accomplish many task and people use them sitting down for prolonged periods. Users will tolerate a few seconds wasted clicking through startup screens so they can get into an app they will use for many minutes or even hours.
By contrast, mobile apps are often used by people on the go and in a hurry. The apps are small and ideally perform a single task. As quickly as possible, people need to be able to get into the app, perform what ever task the app accomplishes and then get back out again. If you're only using an app each time for 30 seconds or so, having to spend 5 seconds each time wading through startup screens is massively annoying.
Mobil hardware is slower and operations can take longer. Depending on its complexity and resources an app can take as much as 10 seconds to launch. In your case you want to add to a startup screen that has to load, connect to a url, display and then have the user perform an operation. That will take another 5-10 seconds minimum. So you're looking at users having to spend 20 seconds or more just getting into your app.
That doesn't sound like much but try mocking up your app and then using it on the go i.e. while walking, waiting for an elevator, going up the stairs, waiting for a red light etc. Test it in social situations. In the middle of conversation say, "Let me check on that" then take out the iPhone launch your app and try to get some information from it. 20 seconds becomes a very long time in all these circumstances.
Even shorter launch times are very annoying if you have to take some action every single time you open the app just to get to the functional part of the app. It's arguably even worse to spring a startup screen on them intermittently so they never know when they open your app how long it will take to get in it. User surprise is not good design.
Instead of forcing users to do something, you should embed advertisements and update notices unobtrusively in the app itself so that people can see them while they are using the app. In the case of advertising, this has the added advantage of putting the adds in view the entire time the user is looking at the app.
I don't know how many times some idiot from marketing has come in and started a feature request with, "We need to force the user to..." The only response to those types of request is to set the marketing weeny on fire. Do that several times and they'll stop trying to systematically alienate your customers.
UIWebViewDelegate has a method that allows you to respond to interaction in a HTML page:
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
Using this, you can catch any links clicked and respond to them in your application by presenting a different view.
Recieving parameters like an id can be done in a few different ways.
1) You can parse the HTML and determine it from the source.
2) You can have a javascript function in the HTML that returns the id. Call it by using
- (NSString *)stringByEvaluatingJavaScriptFromString:(NSString *)script
3) You can also use the delegate method I mentioned.
If you make a link like this: get offer you can catch it in the delegate and retrieve the id from the NSURLRequest.
I hope this will point you in the right direction.
If you do need some kind of startup screen a good option is to use the default.png. The app loads and displays that image before it does anything else.
It's usually used to display the illusion of the user interface before the UI loads completely. However, you could use it to display startup information. Since it displays almost instantly (within 1 sec) it does give your user something to look at while the app loads. In the case of a mock interface, it lets the user see the location of the interface elements and begin moving to activate them before the elements finish loading.
The catch is that the image disappears as soon as the first view loads so you have to load a view behind it that is a duplicate of the image (more ofter the image is screenshot of the view)
In your case you would need to dynamically generate the default.png when the web page updated. Upon launch it would display the information and buy the time the user read it, made a decision and touched the interface, the real web page would have replaced it.
Of course, this system won't work if you want new info at the start of each launch. Instead you'll have to generate the image during one run for use in the next.
In any case, if you launch into a web page the user did not select, I advise that you create a default.png that displays a message along the lines of "Checking for Updates and Info" (or whatever your doing) so the user won't think your app launched and hung.