NSCache is evicting objects everytime I set one! This is nuts.
Here is how I'm adding objects:
[self.inMemoryCache setObject:#{#"data" : data, #"filePath" : filePath} forKey:filePath];
Here is my delegate method willEvictObject:
-(void)cache:(NSCache *)cache willEvictObject:(id)obj
{
NSLog(#"evicted obj %#",[obj description]);
if ([obj isKindOfClass:[NSDictionary class]]) {
NSData *data = [obj objectForKey:#"data"];
NSString *filePath = [obj objectForKey:#"filePath"];
[data writeToFile:filePath atomically:YES];
}else if ([obj isKindOfClass:[NSArray class]]){
NSArray *viewControllerNames = obj;
[viewControllerNames writeToFile:[UINavigationController pathToData] atomically:YES];
}
}
Every time I add object to the cache it evicts it. Really strange.
Any ideas? Here is how I'm allocating it:
navigationController.inMemoryCache = [[NSCache alloc] init];
navigationController.inMemoryCache.delegate = navigationController;
Thanks!
Related
I've got a search page at the moment which will load a list of results for a web-service, but when I return to the search page I would like to 'save' whatever was entered (e.g. 'resto italian') and then display that entry and previous entries into a table view below, like in my following image:
My plan was to use property list serialization - if there isn't already a list, create a property list called history.plist, and populate it with each search term that is made, and display the nearest ten in the table view like above.
What I've tried:
// should create history.plist
- (NSString *)dataFilePath {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
return [documentsDirectory stringByAppendingString:#"history.plist"];
}
/* This is the action for when 'search' is clicked - calls the method above to create
a new plist if it's not already created.
I then try to display the contents of the of the file in the textfield itself
(for testing purposes) but it's not saving/displaying properly at the moment. */
- (IBAction)saveHistory:(id)sender {
NSString *filePath = [self dataFilePath];
if([[NSFileManager defaultManager] fileExistsAtPath:filePath])
{
NSArray *array = [[NSArray alloc] initWithContentsOfFile:filePath];
for (int i = 0; i < (sizeof(array)); i++) {
UITextField *theField = self.searchHistory;
theField.text = [NSString stringWithFormat:#"%#", array];
}
}
UIApplication *app = [UIApplication sharedApplication];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(applicationWillResignActive:) name:UIApplicationWillResignActiveNotification object:app];
}
Any links to tutorials attempting to do this, suggestions towards what I should do, or improvements to what I have would be greatly appreciated.
This should fix the problem:
// This is inside viewDidLoad
UIApplication *myApp = [UIApplication sharedApplication];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(applicationDidEnterBackground:)
name:UIApplicationDidEnterBackgroundNotification
object:myApp];
// This is inside my table view - where I'm loading the file data to display in table cells
NSString *myPath = [self dataFilePath];
BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:myPath];
if (fileExists) {
NSArray *values = [[NSArray alloc] initWithContentsOfFile:myPath];
for (int i = 0; i < values.count; i++) {
cell.historyDisplay.text = [NSString stringWithFormat:#"%#", [values objectAtIndex:i]];
}
}
// This is the file path for history.plist
- (NSString *)dataFilePath {
NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
return [[path objectAtIndex:0] stringByAppendingString:#"history.plist"];
}
// This is my search button - I want to save whatever was typed in the text field, into history.plist, to display in my tableview whenever a user goes to it.
- (IBAction)saveHistory:(id)sender {
NSMutableArray *values = [[NSMutableArray alloc]initWithContentsOfFile:[self dataFilePath]];
if(searchInputTextField.text.length > 0)
[values addObject:searchInputTextField.text];
[values writeToFile:[self dataFilePath] atomically:YES];
[leTableView reloadData];
}
I would use my suggest in comments, but here's some edits to your code that might help in the meantime.
NSArray *array = [[NSArray alloc] initWithContentsOfFile:filePath];
for (int i = 0; i <array.count; i++) {
//I don't know what this line means
UITextField *theField = self.searchHistory;
//Change this line to this
theField.text = [NSString stringWithFormat:#"%#", [array objectAtIndex:i]];
}
I would use Core Data, creating a class, i.e. HistoryRecord with attributes termSearched and timestamp of type NSString and NSDate respectively.
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
#interface HistoryRecordManagedObject : NSManagedObject
#property (nonatomic, retain) NSString *termSearched;
#property (nonatomic, retain) NSDate *timestamp;
+ (NSArray *)findEntity:(NSString *)entity withPredicate:(NSPredicate *)predicate
#end
Implementation
#import "HistoryRecordManagedObject.h"
#implementation HistoryRecordManagedObject
#dynamic termSearched;
#dynamic timstamp;
+ (NSArray *)findEntity:(NSString *)entity withPredicate:(NSPredicate *)predicate
{
NSError *error;
NSArray *fetchedObjects;
/* After set all properties, executes fetch request */
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:entity
inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entityDesc];
[fetchRequest setPredicate:predicate];
fetchedObjects = [managedObjectContext executeFetchRequest:fetchRequest error:&error];
[fetchRequest release];
return fetchedObjects;
}
#end
Of course that's not just this! There are some extra stuff that must be done to use Core Data such as create the model. Read a little about it! It's worth!
Good luck!
In the action for searching, just save the search result to NSUserDefaults.
NSMutableArray *searches = [[NSUserDefaults standardUserDefaults] arrayForKey:#"searches"];
[searches insertObject:textField.text atIndex:0];
[[NSUserDefaults standardUserDefaults] setObject:searches forKey:#"searches"];
[[NSUserDefaults standardUserDefaults] synchronize];
Then load the same array for the tables data source and reload the table in viewwillappear and when keyboard is dismissed.
Replace your saveHistory function by below way:
- (IBAction)saveHistory:(id)sender
{
NSMutableArray *values = [[NSMutableArray alloc]initWithContentsOfFile:[self dataFilePath]];
if(searchInputTextField.text.length > 0)
[values addObject:searchInputTextField.text];
[values writeToFile:[self dataFilePath] atomically:YES];
[leTableView reloadData];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return values.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
}
cell.textLabel.text = [values objectAtIndex:indexPath.row];
}
Below is a class to read and write data using nsarchive
Data.m
-(id)init {
self = [super init];
if(self) {
arr = [[NSMutableArray alloc] init];
}
return self;
}
-(NSString *)getPath {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentPath;
if ([paths count] > 0)
documentPath = [paths objectAtIndex:0];
NSString *draftDataPath = [documentPath stringByAppendingPathComponent:#"draftData.dat"];
return draftDataPath;
}
-(void)saveDataToDisk {
NSString *path = [self getPath];
[NSKeyedArchiver archiveRootObject:arr toFile:path];
}
-(void)loadDataFromDisk {
NSString *path = [self getPath];
self.arr = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
}
At later on, I am adding some objects into arr by doing
CustomerClass.m
- (void) viewDidLoad {
Data *data = [[Data alloc] init];
[data.arr addObject:myObject1]
[data.arr addObject:myObject2]
[data.arr addObject:myObject3]
[data saveDataToDisk];
}
At DisplayData.m, I want to check data.arr by
- (void) viewDidLoad {
Data *data = [[Data alloc] init];
[data loadDataFromDisk];
NSLog(#"length of array is %d",[data.arr count]);
}
On the console, I am getting
length of array is 1
I thought it should be 3 after all.
Please point out what I have just made a mistake in the middle of work if you have any clues about it.
So, I suspect that your "myObjects" are not NSCoding compliant. I just did this:
NSMutableArray *arr = [NSMutableArray arrayWithCapacity:3];
[arr addObject:#"Hello"];
[arr addObject:#" "];
[arr addObject:#"World"];
BOOL ret = [NSKeyedArchiver archiveRootObject:arr toFile:[self getPath]];
NSArray *arr2 = [NSKeyedUnarchiver unarchiveObjectWithFile:[self getPath]];
NSLog(#"count = %d", [arr2 count]);
And the results was "count = 3"
I feel like there's too much code here to do what you're looking for. I think all you need is:
[[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:dataClass] forKey:NSUserDefaultString];
[[NSUserDefaults standardUserDefaults] synchronize];
to save it.
And:
NSData *someData = [[NSUserDefaults standardUserDefaults] objectForKey:NSUserDefaultString];
if (settingsData != nil)
{
dataClass = [NSKeyedUnarchiver unarchiveObjectWithData:settingsData];
}
to retrieve it.
I am developing my first iphone 'Diary' app, which uses custom 'Entry' objects that hold an NSString title, NSString text and NSDate creationDate. When I try to archive an NSMutableArray of Entry objects, and later retrieve them the next time the view loads, the app crashes. I have gone through a bunch of sample codes and examples that use NSKeyedArchivers, but still couldn't figure out why that happens. I am guessing there is a problem with the initialization of the array that holds the entries but not sure...
Here is the code, maybe you could find something that I have persistently overseen..."
//--------- Entry.m---------------
- (id) initWithCoder:(NSCoder *)aDecoder{
if ((self = [super init])) {
self.title = [[aDecoder decodeObjectForKey:#"title"] retain];
self.text = [[aDecoder decodeObjectForKey:#"text"] retain];
self.created = [[aDecoder decodeObjectForKey:#"created"] retain];
}
return self;
}
- (void) encodeWithCoder:(NSCoder *)aCoder{
[aCoder encodeObject:self.title forKey:#"title"];
[aCoder encodeObject:self.text forKey:#"text"];
[aCoder encodeObject:self.created forKey:#"created"];
}
//-------------- Diary View Controller.m
- (NSString *)dataFilePath {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
return [documentsDirectory stringByAppendingPathComponent:kFilename];
}
- (void) writeDataToArchive {
NSMutableData *data = [[NSMutableData alloc] init];
NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc]
initForWritingWithMutableData:data];
[archiver encodeObject:self.entriesArray forKey:#"entriesArray"];
[archiver finishEncoding];
BOOL result = [data writeToFile:[self dataFilePath] atomically:YES];
[archiver release];
[data release];
}
- (void)addItem:sender {
int count = [entriesArray count] +1;
NSString *newEntryTitle = [NSString stringWithFormat:#"Entry %d", count];
Entry *anEntry = [[Entry alloc] initWithTitle:newEntryTitle text:#"-"
created:[NSDate date]];
[entriesArray addObject:anEntry];
[self.tableView reloadData];
[anEntry release];
[self writeDataToArchive];
}
- (void)viewDidLoad
{
[super viewDidLoad];
NSString *filePath = [self dataFilePath];
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
NSData *data = [[NSMutableData alloc]
initWithContentsOfFile:[self dataFilePath]];
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc]
initForReadingWithData:data];
NSMutableArray *array = [unarchiver decodeObjectForKey:#"entriesArray"];
entriesArray = [array mutableCopy];
[array release];
[unarchiver finishDecoding];
[unarchiver release];
[data release];
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:
(NSIndexPath *)indexPath
{
// ... some other stuff
NSUInteger row = indexPath.row;
Entry *entry = [entriesArray objectAtIndex:row];
cell.textLabel.text = entry.title;
return cell;
}
Thanks a lot.
When you read an array back out with NSKeyedUnarchivers you always get an unmutable copy back. You would need to declare *array as NSArray or just get rid of array all together.
entriesArray = [[unarchiver decodeObjectForKey:#"entriesArray"] mutableCopy];
And #JeremyP points out another issue. Since you didn't alloc or retain *array you should not release it.
You should not release array in viewDidLoad because you do not own it.
Please review the Cocoa memory management Rules because there are a couple of other memory management issues in your code. In particular,
self.title = [[aDecoder decodeObjectForKey:#"title"] retain];
self.text = [[aDecoder decodeObjectForKey:#"text"] retain];
self.created = [[aDecoder decodeObjectForKey:#"created"] retain];
in your initWithCoder: method all leak on the assumption the properties are retain or copy.
I need to know how you can find out when all processes (loaded) from a - (void) are done, if it's possible.
Why? I'm loading in data for a UITableView, and I need to know when a Loading... view can be replaced with the UITableView, and when I can start creating the cells.
This is my code:
- (void) reloadData {
NSAutoreleasePool *releasePool = [[NSAutoreleasePool alloc] init];
NSLog(#"Reloading data.");
NSURL *urlPosts = [NSURL URLWithString:[NSString stringWithFormat:#"%#", URL]];
NSError *lookupError = nil;
NSString *data = [[NSString alloc] initWithContentsOfURL:urlPosts encoding:NSUTF8StringEncoding error:&lookupError];
postsData = [data componentsSeparatedByString:#"~"];
[data release], data = nil;
urlPosts = nil;
self.numberOfPosts = [[postsData objectAtIndex:0] intValue];
self.postsArrayID = [[postsData objectAtIndex:1] componentsSeparatedByString:#"#"];
self.postsArrayDate = [[postsData objectAtIndex:2] componentsSeparatedByString:#"#"];
self.postsArrayTitle = [[postsData objectAtIndex:3] componentsSeparatedByString:#"#"];
self.postsArrayComments = [[postsData objectAtIndex:4] componentsSeparatedByString:#"#"];
self.postsArrayImgSrc = [[postsData objectAtIndex:5] componentsSeparatedByString:#"#"];
NSMutableArray *writeToPlist = [NSMutableArray array];
NSMutableArray *writeToNoImagePlist = [NSMutableArray array];
NSMutableArray *imagesStored = [NSMutableArray arrayWithContentsOfFile:[rootPath stringByAppendingPathComponent:#"imagesStored.plist"]];
int loop = 0;
for (NSString *postID in postsArrayID) {
if ([imagesStored containsObject:[NSString stringWithFormat:#"%#.png", postID]]){
NSLog(#"Allready stored, jump to next. ID: %#", postID);
continue;
}
NSLog(#"%#.png", postID);
NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:[postsArrayImgSrc objectAtIndex:loop]]];
// If image contains anything, set cellImage to image. If image is empty, try one more time or use noImage.png, set in IB
if (imageData == nil){
NSLog(#"imageData is empty before trying .jpeg");
// If image == nil, try to replace .jpg with .jpeg, and if that worked, set cellImage to that image. If that is also nil, use noImage.png, set in IB.
imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:[[postsArrayImgSrc objectAtIndex:loop] stringByReplacingOccurrencesOfString:#".jpg" withString:#".jpeg"]]];
}
if (imageData != nil){
NSLog(#"imageData is NOT empty when creating file");
[fileManager createFileAtPath:[rootPath stringByAppendingPathComponent:[NSString stringWithFormat:#"images/%#.png", postID]] contents:imageData attributes:nil];
[writeToPlist addObject:[NSString stringWithFormat:#"%#.png", postID]];
} else {
[writeToNoImagePlist addObject:[NSString stringWithFormat:#"%#", postID]];
}
imageData = nil;
loop++;
NSLog(#"imagePlist: %#\nnoImagePlist: %#", writeToPlist, writeToNoImagePlist);
}
NSMutableArray *writeToAllPlist = [NSMutableArray arrayWithArray:writeToPlist];
[writeToPlist addObjectsFromArray:[NSArray arrayWithContentsOfFile:nowPlist]];
[writeToAllPlist addObjectsFromArray:[NSArray arrayWithContentsOfFile:[rootPath stringByAppendingPathComponent:#"imagesStored.plist"]]];
[writeToNoImagePlist addObjectsFromArray:[NSArray arrayWithContentsOfFile:[rootPath stringByAppendingPathComponent:#"noImage.plist"]]];
[writeToPlist writeToFile:nowPlist atomically:YES];
[writeToAllPlist writeToFile:[rootPath stringByAppendingPathComponent:#"imagesStored.plist"] atomically:YES];
[writeToNoImagePlist writeToFile:[rootPath stringByAppendingPathComponent:#"noImage.plist"] atomically:YES];
[releasePool release];
}
It is as simple as returning a bool at the bottom of the selector being run in the background, and reaload the UITableView.
Thanks to #iWasRobbed:
I have never done this, but just speculating: have you tried returning a BOOL at the very end so that the reloadData function will return TRUE when it gets to that point? I am assuming (possibly incorrectly) that the device serially handles tasks one-at-a-time, so give it a shot.
I'm sitting here for at least half an hour to find a memory leak in my code.
I just replaced an synchronous call to a (touch) method with an asynchronous one using NSOperationQueue.
The Leak Inspector reports a memory leak after I did the change to the code.
What's wrong with the version using NSOperationQueue?
Version without a MemoryLeak
-(NSData *)dataForKey:(NSString*)ressourceId_
{
NSString *cacheKey = [self cacheKeyForRessource:ressourceId_]; // returns an autoreleased NSString*
NSString *path = [self cachePathForKey:cacheKey]; // returns an autoreleased NSString*
NSData *data = [[self memoryCache] objectForKey:cacheKey];
if (!data)
{
data = [self loadData:path]; // returns an autoreleased NSData*
if (data)
{
[[self memoryCache] setObject:data forKey:cacheKey];
}
}
[[self touch:path];
return data;
}
Version with a MemoryLeak (I do not see any)
-(NSData *)dataForKey:(NSString*)ressourceId_
{
NSString *cacheKey = [self cacheKeyForRessource:ressourceId_]; // returns an autoreleased NSString*
NSString *path = [self cachePathForKey:cacheKey]; // returns an autoreleased NSString*
NSData *data = [[self memoryCache] objectForKey:cacheKey];
if (!data)
{
data = [self loadData:path]; // returns an autoreleased NSData*
if (data)
{
[[self memoryCache] setObject:data forKey:cacheKey];
}
}
NSInvocationOperation *touchOp = [[NSInvocationOperation alloc] initWithTarget:self selector:#selector(touch:) object:path];
[[self operationQueue] addOperation:touchOp];
[touchOp release];
return data;
}
And of course, the touch method does nothing special too. Just change the date of the file.
-(void)touch:(id)path_
{
NSString *path = (NSString *)path_;
NSFileManager *fm = [NSFileManager defaultManager];
if ([fm fileExistsAtPath:path])
{
NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys:[NSDate date], NSFileModificationDate, nil];
[fm setAttributes: attributes ofItemAtPath:path error:nil];
}
}