There is no done handler in removePendingNotificationRequests huh? How are you supposed to know when a request has been removed?
Suppose you have a table view or something showing these requests. And you remove one - you need to remove that cell row to reflect that. But as removePendingNotificationRequests is async, according to the docs, it sounds like it would be incorrect to assume that requests would always be removed instantly.
Related
I have an API code, which loads a data necessary for my application.
It's as simple as:
- (void) getDataForKey:(NSString*) key onSuccess:(id (^)())completionBlock
I cache data returned from server, so next calls of that functions should not do network request, until there is some data missing for given key, then I need to load it again from server side.
Everything was okey as long as I had one request per screen, but right now I have a case where I need to do that for every cell on one screen.
Problem is my caching doesn't work because before the response comes in from the first one, 5-6 more are created at the same time.
What could be a solution here to not create multiple network request and make other calls waiting for the first one ?
You can try to make a RequestManager class. Use dictionary to cache the requesting request.
If the next request is the same type as first one, don't make a new request but return the first one. If you choose this solution, you need to manager a completionBlock list then you will be able to send result to all requesters.
If the next request is the same type as first one, waiting in another thread until the first one done. Then make a new request, you API will read cache automatically. Your must make sure your codes are thread-safe.
Or you can use operation queues to do this. Some documents:
Apple: Operation Queues
Soheil Azarpour: How To Use NSOperations and NSOperationQueues
May be there will be so many time consuming solutions for this. I have a trick. Create a BOOL in AppDelegate, its default is FALSE. When you receive first response, then set it TRUE. So when you go to other screen and before making request just check value of your BOOL variable in if condition. If its TRUE means response received so go for it otherwise in else don't do anything.
I have the following event handler in my datacontext:
manager.hasChangesChanged.subscribe(function (eventArgs) {
hasChanges(eventArgs.hasChanges);
});
and in Chrome I've set a break point on the "haschanges(eventArg.haschanges);" line.
The moment I load my app and the process of fetching data begins, this breakpoint is hit. It then proceeds to be repeatedly hit and the "hasChanges" property varies between "true" and "false" many times.
I know from further debug breakpoints that a simple query that "expands" a related table via its navigation property triggers a visit to my "hasChangesChanged" event handler.
What I don't know - as the "eventArgs" is so big and complex - is exactly which of my 5 or so related entities being retrieved is triggering the "true" on the "hasChanges" property. Is there a property within the eventArgs I can inspect to determine which current entity has caused the trip to the hasChangesChanged event handler?
I'm puzzled about why any of what I'm doing is setting "hasChanges" to true as all I do in the first instance is retrieve data. As far as I'm aware, nothing is changed whatsoever at the point the entity manager is convinced that something has changed.
To elaborate, my app prefetches lots of data used for a tree structure at the point where it is sitting waiting for first input from the user. As the user has not had an opportunity of touching anything in the app by this point, why would breeze think that any of the entities concerned have been changed when they've simply been read in from the database?
Use the EntityManager.entityChanged event if you want fine grained information about what has changed. This event gives much more detail but is fired much more often.
http://www.breezejs.com/sites/all/apidocs/classes/EntityManager.html
I'm programmatically pushing an object (using pushObject) into a list that is sortable. My problem becomes that if I try $(selector).sortable('refresh') or $(selector).sortable('serialize') the serialize doesn't contain the recently added dom item. I can console.log($(selector)) and it seems to know that the dom item has been added though.
My original thought is there an event to watch for once pushObject has finished? Or a callback?
Is there an event to watch for on pushObject?
Easiest way to do this is add an observer that fires when the list length has changed. But probably that's not gonna be enough in this case.
It sounds like this is a timing issue. If you try to call refresh right after pushObject (or even in an observer) the refresh code is going to run before the dom has been updated.
The trick is to make sure you are calling $(selector).sortable('refresh') after the new elements have been written to the dom. That could be from a didInsertElement hook on the dom item's view or from an observer, but as #Luke reminded me in comments best way to do it is by scheduling refresh to run after render has completed. Something like:
Em.run.schedule('afterRender', this, this.refreshSortable)
Not sure how to best explain this - If I use blocks to load images for UITableViewCells, how best can I ensure that when an image actually finishes loading - it is the correct image for the cell. Say I'm making an app with user icons - so cell 5 is for John and it starts loading John's image. Say that request gets hung up and by the time it returns, that cell has been reused for Bill at cell 23. We obviously don't want to load John's icon - we just want Bill's.
This is a simplified explanation. I know that we can check if a cell is visible in the block before setting the image - but say in a different scenario I have a method that makes a remote request when called. When the remote request is done, it calls a block defined in that method that updates the UI. If I call it and before it returns I call it again and only want the most recent call's block executed. Is there a good pattern for doing this?
Currently, I try to store a variable that has some state in the method so that when it returns I can check if that state is still valid. Just thought I'd see if there was a better way. Thanks.
Just checking if any updates on this.
Let's assume that I have a program that parses a RSS feed.
I have a method that runs in a thread which keeps checking for updates. If updates is found a NSNotification is created. Is this a stupid implementation?
And is it possible to pass custom parameters within a NSNotification, such as the elementId that was updated.
Sounds like a good plan to me. Yes, you can pass user data.
See NSNotification's notificationWithName:object:userInfo:. The userInfo is an NSDictionary so you can pass whatever you like around.