I get an array (containing text) called titleArray from json which I populate a uitableview with. I would like to cache it in memory so that data for the screen loads once, it will not need to load again per session. I've never done this..
basically I have 2 methods:
- (void)requestFinishedWithResult:(NSDictionary*)result
- (void)requestFailed
depending on if I get anything from the server.
Somewhere in the - (void)requestFinishedWithResult:(NSDictionary*)result I'm thinking I need an additional array to store the titleArray data in...and then do something like this: ??
-(void)requestFailed
{
if (titleArray != nil)
{
storeArray = titleArray;
}
}
or something like that? but I really don't know how it should work. Any help is appreciated.
Depends on what kind of persistance you want. You can store it on the disk and then load it and have a mechanism to update that cached data. Or, you can just store on an ivar and retain it's value, this way you will have the data for the duration of the application.
Related
I'm getting the above layout from Parse. What I want is vid 1, 2, and 3 to be in the same row; associated with same object ID. How can I do this? My ultimate goal is to easily retrieve 10 video dictionary's per user on a table view. Will any of this make a difference? I'm saving like this.....
videoDict = ["id":videoId, "title":vidTitleText, "description":vidDescription, "image":vidIMG]
let videoSave = PFObject(className:"UserVideos")
videoSave["user"] = PFUser.currentUser()!.username
videoSave["userObjectId"] = PFUser.currentUser()!.objectId
videoSave["vid\(saveValueLBL.text!)"] = videoDict
videoSave.saveInBackgroundWithBlock { (success, error ) -> Void in
if success == true
{
print("Succesfull")
}
}
Where you have let videoSave = PFObject(className:"UserVideos") you are creating a new videoSave object each time. you need to move that outside of your loop so that you're accessing the same object each time instead of making a new one. However, the way you currently have your code set up you'll run into problems, because each object can only have one synchronous action called on it (in this case, your save), so the second, third, maybe even all the way to the 10th save may not occur because it needs the first one to finish before the next one can be called. You need to create your object outside your loop, run the loop, then call the save at the end to make sure it isn't saving until all of the data is updated.
If this isn't all inside of a loop, you need to get the videoSave object back each time, perhaps by storing it onto your user, and then fetching it from the user object.
Put everything outside the loop and keep just the code below inside the loop:
videoDict = ["id":videoId, "title":vidTitleText, "description":vidDescription, "image":vidIMG]
videoSave["vid\(saveValueLBL.text!)"] = videoDict
From what I understand although I saved information in Parse as a Dictionary this is in fact an invalid data type. That's why I'm having trouble retrieving because Parse doesn't recognize the info.
I already have a tableView with data in it. IF you tap a cell/row it pushes to an edit type of view. Is there anyway to edit core data's data other than: By edit, i mean i already have data inserted into my context. I have loaded my data into my view, the user can change the existing data, and re save it.
.h
//Below is the entity/entity's class name 'Amm'
Amm *amm;
.m
-(IBAction)save
{
[self.amm setValue:self.nameField.text forKey:#"name"];
[self.amm setValue:self.nicknameField.text forKey:#"nickname"];
[self.navigationController popViewControllerAnimated:YES];
NSError *error;
if (![self.managedObjectContext save:&error]) {
//Handle Error
}
}
I want this code to work, however the design pattern of my app isnt allowing this code to work for me as it does in other parts of my app. Thank you very much for any and all help!
I assume from what you've said you have:
A table view listing your managed objects
A view where you can edit the values of a managed object
A save button bound to the save method
What's the actual issue? I'm assuming when you tap save that:
The values in self.nameField.text isn't setting self.amm.name
The values in self.nicknameField.text isn't setting self.amm.nickname
Is that right? If so perhaps try the following code to set the managed object values:
self.amm.name = self.nameField.text
self.amm.nickname = self.nicknameField.text
If that's not the issue and you are actually setting the managed object values properly, is it that you just need to refresh the table-view? Perhaps use some NSLog commands to log every step of the applications progress.
I'm currently using a singleton as a data store for my app. I essentially store a number of events that are pulled and parsed from a web service and then added as needed. Each time I make a request from the web service, I parse the results and see if the items already exist. If they do, I delete them and add the updated version provided by the web service.
Everything appeared to be working properly until I fired up the Instruments panel to find out that my system is leaking the objects every time it loads them from the web service (from the second time on). The core method where things appear to be messing up is this one, which is located in my HollerStore singleton class:
- (void)addHoller: (Holler *)h
{
//Take a holler, check to see if one like it already exists
int i = 0;
NSArray *theHollers = [NSArray arrayWithArray:allHollers];
for( Holler *th in theHollers )
{
if( [[th hollerId]isEqualToString:[h hollerId]] )
{
NSLog(#"Removing holler at index %i", i);
[allHollers removeObjectAtIndex:i];
}
i++;
}
[allHollers addObject:h];
}
Quick explanation: I decided to copy the allHollers NSMutableArray into theHollers because it's being updated asynchronously by NSURLConnection. If I update it directly, it results in a crash. As such, I switched to this model hoping to solve the problem, however the Instruments panel is telling me that my objects are leaking. All the counts are exactly the # of items I have in my data set.
From what I can tell removeObjectAtIndex isn't effectively removing the items. Would love to get the thoughts of anybody else out there on three things:
Is my analysis correct that something else must be retaining the individual hollers being added?
Should I be using CoreData or SQLite for storing information pulled from the web service?
Do you know how long data stored in a Singleton should be available for? Until the app is killed?
Update
I think I've found the source, however perhaps someone can provide some clarity on the proper way to do this. I've created a method called parseHoller which takes a dictionary object created through SBJSON and returns my own model (Holler). Here are the last couple lines:
Holler *h = [[[Holler alloc] initFromApiResponse:hollerId
creatorId:creatorId
creatorName:creatorName
creatorImageUrl:creatorImage
comments:comments
attendees:attendees
wishes:wishes
invitees:invites
createdAt:createdAt
text:text
title:title
when:when]autorelease];
//(some other autorelease stuff is here to clean up the internal method)
return h;
I figured that since I'm returning an autoreleased object, this should be fine. Do you see anything wrong with this?
Have you tried to do a retain count on the objects that is leaking? Maybe that could clear up when or where it is being retained.
The code should be
[putObjectHere retainCount];
and then write to an NSLog
Hope it gives you something
Peter
I'm using SQL to store data in my application. I read data in the app delegate and store it in an array like so.
(First I read from the database and store in aFlashcardSet and then this)
// Add the flashcardSet to the main Array
[mainSetsArray addObject:aFlashcardSet];
In my next view I then copy the data from the app delegate.
flashcardsAppDelegate *delegate = [[UIApplication sharedApplication] delegate];
self.setsArray = delegate.mainSetsArray;
Then I pass one object from the set to the final view.
cardDetailViewController.thisCardSet = [setsArray objectAtIndex:row];
The problem is when I read the data in the final view and use to set UI elements the app crashes, the code works fine with data hard coded during the second phase and the database data is shown fine during the second phase (to populate a table view). I've tried outputting the data at all stages and it is all correct until the final view where it either crashes or shows incorrect values (file names or random letters rather than the actual text).
I have also tried to read the database data inside the final view and set it to thisCardSet but it still suffers the same problem.
Any ideas?
Thanks.
The problem was inside one of my custom classes I wasn't using self, so I was writing.
aString = string;
Rather than -
self.aString = string;
So I was losing data down the line, feel really stupid but hope it help's someone else =].
i have made one list of images + respective data in tableview.
it takes long time while loading
i want to make multithreading two methods
1> parsing of data
2> parsing of images
i want to execute parsing of data first after that i can select any of rows listed even though images not been loaded(/parsed) because the images is parsed after the parsing of data and it takes long time.
from where should i call these both the methods.
and how enable the selection on row after parsing of the data...
how to do multithread both the methods
waiting for your great responce
Thanking in advance
You likely don't want to use NSThreads - at least not directly.
What you do is subclass NSOperation.
There are a few ways to do what you have in mind. If you know the total number of rows in your table right from the start, then things are simpler:
Make a subclass of NSOperation called MyParseDataOperation. Then make one MyParseDataOperation for each row in your table. When the operation is done, you need to message your main thread with the resulting data.
Code below is full of errors, incomplete. etc.
ie in your MyParseDataOperation class:
MyParseDataOperation
-(id)initWithStuff:(NSURL*)stuff forTableRow:(int)row;
{
blah blah -
// here is where I make sure I have all the data I need for main() which is called in the background on some random thread at some future time.
}
-(void)main;
{
// use data like Urls, file names, etc passed in to the initWithStuff method
get stuff
parse stuff
// ok now you have the data
NSMutableDictionary* parsedData = [NSMutableDictionary dictionary];
[parsedData setObject:[NSNumber numberWithInt:row] forKey:#"row"];
[parsedData setObject:stuff i figured out forKey:#parsed];
[tableDataSource performSelectorOnMainThread:#selector(dataParsed) withObject:parsedData];
}