Two absolute beginner questions.
I have working code in my main.js enterState.
enterState: function(context) {
..
//keepAlive
var now = SC.DateTime.create();
if (now.get('hour') < 18){
SC.info ("main_state:enterState:go %#", now.get('hour'));
this.timer = SC.Timer.schedule({
target: this,
action: '_timerFired',
interval: 5000,
repeats: YES
});
} else {
SC.info ("MainState:enterState:nogo %#", now.get('hour'));
};
..
this.mainPane.append();
},
_timerFired: function(){
SC.info ("_timerFired %#", Date.now());
},
exitState: function() {
SC.info('main_state:exitState');
this.timer.invalidate();
this.mainPane.remove();
},
Question 1: the enterState is used every time a user goes to the main view, is the timer schedule initialized once or every time a user switches views?
Question 2: I think I need a query. e.q. the logged in username, to prevent an automatic logout due to the expired session MaxInactiveInterval. Is there sample code to get the spring username in the _timerFired function?
I saw the answer/solution of Maurits, thanks, but it is too complicated for me.
This timer will be scheduled every time this state is being entered. If this is the root state of the application, that will be once. If this state is used to display the mainPane and you are leaving this state somehow, and returning, then this timer will be initialized every time you enter this state.
You could keep the username as property of the current state (this._username) and as _timerFired is called with this being the current state (SC.Timer will take care of that through the target) you will have access to it. You'd need to set it somehow of course. Another solution is to read it directly from the controller you use for the login procedure.
Nevertheless, this solution is prone to trouble. The main reason for this is that you are creating implicit states. I mean that being authenticated is an application state, and instead of making this explicit through the state chart, you hide it within one of the states. As I wrote in the comment: I came to the solution I posted in the other question because of trying many different solutions and hitting trouble. What I learned from those issues is that the statechart is your friend, and really trying to work with it will help you avoid loads of headaches!
Related
I tried to show a progress in angulardart, and thought that a Future would be good for this. But then i realized that a Future must be recursive to show a progress, since the Future returns immediately and the lengthy operation is executed afterwards.
If i create a Future that calls itself until the end condition is met it works with the progressbar. But i think this could not be a very good practice sind these calls will raise the memory on the stack with every recursion. Just consider a loop going through 1 billion datasets that could run a few hours and every loop calls a new Future within the current Future.
Is there a better way to create a loop that needs a certain amount of time to do work on every element (including calling a website that must be done asynchronous and evaluating the return value)? During the loop the user should see a progress that shows him "x/1000000 done".
I think it must be done with a Future since the UI needs to reload after initiating the loop, but a recursive Future seems like a bad idea to me.
You need the future to return back to you right away on the web because it is a single threaded platform. If an async action didn't return until it was complete then you would hang the browser and it wouldn't be a great experience to the user.
Instead you have a couple of options:
Dart has the ability to make the future look like it is synchronous with the await keyword. So you can do something like:
void performAction() async {
showProgress = true;
await expensiveRpc();
showProgress = false;
}
This would require the progress to be intermediate, as you aren't actually updating the progress bar as it goes along. That said if you don't really get progress events from your RPC this is probably the better solution.
Now if your RPC or action gives you some kind of feedback as it goes you can do something a bit nicer with a stream.
void performAction() {
showProgress = true;
expensiveRpc().listen((progress) {
if (progress.done) {
showProgress = false;
} else {
percentComplete = progress.value;
});
}
Really it depends more on the RPC or service you are interacting with on how you can update the progress nicely more than the progress itself.
Meanwhile i recognized that a Future-method returns immediately without executing anything in the method-body. So the solution is pretty easy:
Just declare the rpc with a Future, do whatever you need to do in the method and when calling it, use then(...) to do what you need to do after collecting the data.
int progress = 0;
int progressMax = 100;
bool progressCanceled = false;
Future rpc(var data)
async{
for(progress=0; progress<progressMax, progress++)
{
// do whatever you need to do with data
if(progressCanceled)
return;
}
}
rpc(data).then(
{
if(progressCanceled)
return;
// do whatever is needed after having received that data
});
rpc is executed and the calling process can continue while rpc does what rpc has to do. The main program can handle button clicks to set progressCanceled to true and the rpc-method will ask for the state and stop processing if it is set.
In a page's domready event I'm setting an event listener for a button that sets a Background Sync event in a page on my website (when offline), but even if the service worker has been loaded already on previous page visits, this line of code never resolves the promise, its status stays "Pending" indefinitely.
navigator.serviceWorker.ready.then(function (sw) {
$('#elt').on('click', function () {
sw.sync.register('contact-form-submission');
Since I know the sync event won't need to be set until after a form is completed, I tried wrapping this code in a setTimeout() of 3 seconds, which worked! My question is why this might be, I haven't been able to find anyone else indicating the .ready event wouldn't be available when the page is first loaded. Insight appreciated.
I have a MVC web database application where the records are basically documents with items.
Documents are locked, not items and they locked by code when the user looks in any of 4 or 5 different screens for any given document.
there is a 10 minute time out on the record locks. The user does not do anything with the record for 10 minutes and another can take the record. There is code that detects the lock was lost and taken by someone else. It works fine and is technically sound.
The workflow of the application relies on the lock being released when the user leaves the screen or closes the browser, or if they press the refresh button.
These are work fine on windows and android but not on ipad.
I understand there is no
beforeunload
on ios but I though there was
unload
or
pageHide
neither of these work.
Here is my code.
var isOnIOS = navigator.userAgent.match(/iPad/i)||
navigator.userAgent.match(/iPhone/i); var eventName = isOnIOS ?
"pageHide" : "beforeunload";
window.addEventListener(eventName, function (event) {
ReleaseRecordLock(); } );
This code works on all mentioned platforms except that the events don't fire on IOS.
It looks to me that this is deliberate on Apple's part so I an not thinking it will change.
So now the question.
What can I do to ensure that these records get unlocked if a user changes screens or closes the browser. If they don't no users will be able to access the document for 10 minutes which will not be acceptable.
Thanks
Edit... I don't need pop ups or notification. I just need reliable unlocking
As mentioned above none of the events that are supposed to work actually fire. pageHide and unload do nothing.
I found mentions of how to get around this problem but no details so I though I would detail it here.
This solutions works with areas and standard sites.
My solution to get around part of this was to detect if the browser is running on IOS and if so to change the link in the menu.
<li>
#{
if(Request.UserAgent.Contains("iPad") || Request.UserAgent.Contains("iPhone"))
{
<a onclick="IOSReleaseLock('controller', 'action')" href="javascript:void(0);">LinkText</a>
}
else
{
#Html.ActionLink("link Text","action","controller",new { Area = "Tasks" },null);
}
}
</li>
Every single link in the application has to have a function called IOSReleaseLock() available or the solution will not work. Not all pages lock records, only those that actually change documents. Reports, and basic website functions such as change password, log out, and the sys admin stuff do not need record locks.
At this point I have 2 versions of IOSReleaseLock()
This is the version that is used on pages that do not required unlocking.
function IOSReleaseLock(_controller, _action)
{
var url = '/__controller__/__action__/';
url = url.replace('__controller__', _controller);
url = url.replace('__action__', _action);
window.location.href = url;
}
This is the version that is placed on pages that required unlocking.
function IOSReleaseLock(_controller, _action )
{
var url = '/__controller__/__action__/';
url = url.replace('__controller__', _controller);
url = url.replace('__action__', _action);
UnloadingRecordLockRelease();
window.location.href = url;
}
Every link has a wrapper so every single page must load a version of IOSReleaseLock(). This includes your /home/index or where ever your application starts. If you miss one then once you are on that page your menu system links will not work anymore.
Pages that require the UnloadingRecordLockRelease() function load that version and the pages that do not require unlocking load the first version.
On IOS every time you click a link, IOSReleaseLock() is called. This may seem to be obvious, but for clarity, the version of IOSReleaseLock() that executes is the version that is on the current page, not the version on the page you are going to.
So as long as the user stays on the site and does not close the browser then the records are unlocked correctly.
When the user logs out all records are unlocked but I have no solution for when the browser tab is closed or when the browser is closed without the user logging out.
At the Time of Signing In to my Application, I am getting Time for which the current user login is valid["liveTime"] from the BackEnd API for a particular user. And I am saving this liveTime(parameter) to the NSUserDefaults.
My requirement is to show the Sign In page again when liveTime will become 0. And If that particular user kills the app and if liveTime is greater than 0, It will show the Default page after Sign In happens.
Please share your experience how to do or what is the best practices to resolve this kind of problems. Please share the code snippets if someone has already done it.
Maybe this can help you.
func afterDelay(seconds: Double, closure: () -> ()) {
let when = dispatch_time(DISPATCH_TIME_NOW, Int64(seconds * Double(NSEC_PER_SEC)))
dispatch_after(when, dispatch_get_main_queue(), closure)
}
Call the function
self.afterDelay(4) {
// Write what you want to happen after 4 sec. You can increase the number
self.dismissViewControllerAnimated(true, completion: nil)
}
The solution is to keep track in NSUserDefaults of your last login timestamp and the last maximum live time retrieved from the server (unless it must be fetched at that moment [thing that would be inappropriate because of the lag that communicating with a server brings]).
Then, in your initial controller's viewDidLoad or in your AppDelegate (the choice is yours)check if that time is after the maximum allowed and proceed accordingly.
UPDATE:
Best Practices:
1.- Add some kind of waiting page, to leave the user there waiting until you retrieve that data from the server.
2.- After receiving that Data, check for the timestamp saved in your NSUserDefaults and proceed either to login or welcome pages
3.- If the user logs in, then update the timestamp in NSUserDefaults
So here's my problem. I have code set up that calls a function whenever my player is over its last destination in the a* pathfinding array...
public function rakeSoil(e:Event):void {
var:Cell = Grid.getCellAt(player.x/50, player.y/50);
if (cell.isWalkable == false) {
return;
else {
//here is where i want to do the sleep code so this doesnt happen straight away? If possible.
target.sprites = [grass];
}
}
thanks guys :)
Generally, the "right" way to delay execution of something is to use a Timer.
Hacking up some kind of a sleep function could cause problems, since Flash runs in a single thread, so you won't be able to do anything else while your function is running, including refreshing the screen (making your game appear as if it crashed, or at least started lagging).
If you're absolutely, positively sure you want to do this, you could call the getTimer() function in a loop to see if a certain amount of miliseconds has passed.