Search Results

Search found 10298 results on 412 pages for 'self teaching'.

Page 197/412 | < Previous Page | 193 194 195 196 197 198 199 200 201 202 203 204  | Next Page >

  • Why does Custom UITableViewCell *sometimes* cause an NSInvalidArgumentException?

    - by Wayne Hartman
    I have created a custom UITableViewCell, but when I dequeue the cell, sometimes it throws an NSInvalidArgumentException: [UITableViewCell nameLabel]: unrecognized selector sent to instance 0x3b4e7f0 Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* -[UITableViewCell nameLabel]: unrecognized selector sent to instance 0x3b4e7f0' Now, my custom UITableViewCell does have an attribute nameLabel, so I am confused why it is throwing this error. Below is the code I use to dequeue the cell: - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { NSUInteger row = [indexPath row]; CTMenuItemVO* key = [[[self retrieveCartItems] allKeys] objectAtIndex:row]; NSNumber* quantity = [[self retrieveCartItems] objectForKey:key]; static NSString* SectionsTableIdentifier = @"SectionsTableIdentifier2"; OrderItemCell* cell = (OrderItemCell*)[tableView dequeueReusableCellWithIdentifier: SectionsTableIdentifier]; if (cell == nil) { NSArray* topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"OrderItemCell" owner:nil options:nil]; for(id currentObject in topLevelObjects) { if ([currentObject isKindOfClass:[UITableViewCell class]]) { cell = (OrderItemCell*) currentObject; break; } } } cell.nameLabel.text = key.Name; cell.qtyLabel.text = [quantity stringValue]; return cell; }

    Read the article

  • What's the benefit of calling new on an object instance?

    - by Geo
    I'm reading [Programming Perl][1], and I found this code snippet: sub new { my $invocant = shift; my $class = ref($invocant) || $invocant; my $self = { color => "bay", legs => 4, owner => undef, @_, # Override previous attributes }; return bless $self, $class; } With constructors like this one, what's the benefit of calling new on an object instance? I assume that it's what it's for, right? My guess is that if anyone would want to write such a constructor, he would have to add some more code that copies the attributes of the first object to the one about to be created.

    Read the article

  • F# replace ref variable with something fun

    - by Stephen Swensen
    I have the following F# functions which makes use of a ref variable to seed and keep track of a running total, something tells me this isn't in the spirit of fp or even particular clear on its own. I'd like some direction on the clearest (possible fp, but if an imperative approach is clearer I'd be open to that) way to express this in F#. Note that selectItem implements a random weighted selection algorithm. type WeightedItem(id: int, weight: int) = member self.id = id member self.weight = weight let selectItem (items: WeightedItem list) (rand:System.Random) = let totalWeight = List.sumBy (fun (item: WeightedItem) -> item.weight) items let selection = rand.Next(totalWeight) + 1 let runningWeight = ref 0 List.find (fun (item: WeightedItem) -> runningWeight := !runningWeight + item.weight !runningWeight >= selection) items let items = [new WeightedItem(1,100); new WeightedItem(2,50); new WeightedItem(3,25)] let selection = selectItem items (new System.Random())

    Read the article

  • Either .each do or .all isn't working how I think it should

    - by user1299656
    So whenever someone rates a shop, I want the Shop model to calculate its new average rating and store that in the database (instead of calculating the average every time someone looks at it). So I wrote the segment of code that follows, and it doesn't work. The loop always iterates exactly once, no matter how many shop_ratings in the database exist that have the shop's id as their shop_id. I played around with it a bit and found that every time a new rating is submitted the function is called successfully, but it only runs the loop once and sets the average to what the first rating was. I don't know if the "query" that sets the ratings variable is wrong or if it's the loop that's wrong. class Shop < ActiveRecord::Base has_many :shop_ratings attr_accessible :name, :latitude, :longitude validates_presence_of :name validates_presence_of :latitude validates_presence_of :longitude def distance_to(lat, long) return (self.longitude - long) + (self.latitude - lat) end def find_average total = 0 count = 0 ratings = ShopRating.all(:conditions => {:shop_id => id}) ratings.each do |submission| total = total + submission.rating count = count + 1 end update_attribute :average_rating, total/count end end

    Read the article

  • NSFetchedResultsChangeUpdate crashes when called on a searched tableview

    - by Zachary Fisher
    So I nearly have this thing figured out, but I am stumbling over the NSFetchedResultsChangeUpdate when I update my managedObjectContext from a detail view that was entered after searching the table. I have a tableview generated from a core data set. I can enter a detail view from this table and make changes without any issue. I can also search the table and make changes MOST of the time without any issues. However, on certain objects, I get an "Exception was caught during Core Data change processing". I tracked this down to the NSFetchedResultsChangeUpdate. I'm using the following code: case NSFetchedResultsChangeUpdate: if (searchTermForSegue) { NSLog(@"index info:%@.....",theIndexPath); NSLog(@"crashing at the next line"); [self fetchedResultsController:self.searchFetchedResultsController configureCell:[tableView cellForRowAtIndexPath:theIndexPath] atIndexPath:theIndexPath]; break; } else { [self fetchedResultsController:controller configureCell:[tableView cellForRowAtIndexPath:theIndexPath] atIndexPath:theIndexPath]; } break; When the table is not being searched, it runs the else method and that works 100% of the time. When the table is being searched, it runs the if (searchTermForSegue) and that works most of the time, but not always. I logged theIndexPath and discovered the following: When it works, theIndexPath is correctly reporting the objects indexPat, when it fails, the wrong theIndexPath has been called. For example, if I do a search that narrows the tableView to 3 sections, 2 items in first, 1 in second, 1 in third, I get the following nslog: On first object: index info:<NSIndexPath 0xb0634d0> 2 indexes [0, 0]..... on second object: index info:<NSIndexPath 0xb063e70> 2 indexes [0, 1]..... on third object: index info:<NSIndexPath 0xb042880> 2 indexes [1, 0]..... but on the last object: index info:<NSIndexPath 0x9665790> 2 indexes [2, 17]..... it should be calling [2, 0] Note that I am simply updating these objects, not deleting them or adding new ones. Any thoughts would be appreciated!

    Read the article

  • OpenSSL compatible API for Scala?

    - by pfleidi
    Hello, I'm working on a project with a friend. He's implementing his software in Ruby and I'm doing my stuff in Scala (with Lift). We're using some asynchronous encryption and he is using the ruby OpenSSL bindings for that: key = OpenSSL::PKey::RSA.generate(4096) self.public_key = key.public_key self.private_key = key What I'm looking for is a simple API which is compatible to OpenSSL and runs on the JVM. I need it to create key-pairs and to encrypt and sign our payload. Do you have any suggestions?

    Read the article

  • Is it possible to create a UINavigationController within a ModalPopup?

    - by aloo
    Hi I have a modalViewController that I am popping up using [self presentModalViewController:myController animated:YES]; I have an event occurring within myController which I would like to result in another controller being pushed onto the navigation stack ON TOP OF myController (which again has been presented modally). How can I do this? I have tried the following from within myController: UINavigationController* navController = [[UINavigationController alloc] initWithRootViewController:self]; NewController* n = [[NewController alloc] init]; [navController pushViewController:n animated:YES]; [n release]; This does not work however....

    Read the article

  • optimize python code

    - by user283405
    i have code that uses BeautifulSoup library for parsing. But it is very slow. The code is written in such a way that threads cannot be used. Can anyone help me about this? I am using beautifulsoup library for parsing and than save in DB. if i comment the save statement, than still it takes time so there is no problem with database. def parse(self,text): soup = BeautifulSoup(text) arr = soup.findAll('tbody') for i in range(0,len(arr)-1): data=Data() soup2 = BeautifulSoup(str(arr[i])) arr2 = soup2.findAll('td') c=0 for j in arr2: if str(j).find("<a href=") > 0: data.sourceURL = self.getAttributeValue(str(j),'<a href="') else: if c == 2: data.Hits=j.renderContents() #and few others... #... c = c+1 data.save() Any suggestions? Note: I already ask this question here but that was closed due to incomplete information.

    Read the article

  • iOS iPad Master Detail template can't interact with detail view

    - by CraigularB
    I have an iPad app generated from the Master-Detail template in XCode. The iPad Storyboard has under the Detail View Controller a View that holds a ScrollView which holds an ImageView. In the DetailViewController.m file I added the following code to allow the ScrollView to move and zoom the image: -(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView { return self.comicImage; } This works great on the iPhone (it's a universal app) but not the iPad; I can scroll and zoom the image on the iPhone no problem, but on the iPad it's like the ScrollView isn't responding to the touches, and I can't figure out how to pass the touches on to the ScrollView. I've already deactivated the popover controller from appearing with a right swipe like this: self.splitViewController.presentsWithGesture = NO; How do I make it so the user can interact with the ScrollView in the DetailViewController?

    Read the article

  • Given an instance of a Ruby object, how do I get its metaclass?

    - by Stanislaus Wernstrom
    Normally, I might get the metaclass for a particular instance of a Ruby object with something like this: class C def metaclass class << self; self; end end end # This is this instance's metaclass. C.new.metaclass => #<Class:#<C:0x01234567>> # Successive invocations will have different metaclasses, # since they're different instances. C.new.metaclass => #<Class:#<C:0x01233...>> C.new.metaclass => #<Class:#<C:0x01232...>> C.new.metaclass => #<Class:#<C:0x01231...>> Let's say I just want to know the metaclass of an arbitrary object instance obj of an arbitrary class, and I don't want to define a metaclass (or similar) method on the class of obj. Is there a way to do that?

    Read the article

  • Database Error django

    - by Megan
    DatabaseError at /admin/delmarva/event/ no such column: delmarva_event.eventdate I created a class in my models.py file: from django.db import models from django.contrib.auth.models import User class Event(models.Model): eventname = models.CharField(max_length = 100) eventdate = models.DateField() eventtime = models.TimeField() address = models.CharField(max_length = 200) user = models.ForeignKey(User) def __unicode__(self): return self.eventname and now when i try to view my events in my admin or my main_page it gives me the error that there is no eventdate. I tried syncing the db again but nothing changed. Also, I hashtagged eventdate out to see if I get a different error and then it states that delmarva_event.eventtime does not exist as well. I It is weird because it does not have a problem with eventname. Any suggestions would be greatly appreciated!

    Read the article

  • What's the preferred way to use helper methods in Ruby?

    - by DR
    Disclaimer: Although I'm asking in context of a Rails application, I'm not talking about Rails helpers (i.e. view helpers) Let's say I have a helper method/function: def dispatch_job(job = {}) #Do something end Now I want to use this from several places (mostly controllers, but also a few BackgrounDRb workers) What's the preferred way to do this? I can think of two possibilities: 1. Use a class and make the helper a static method: class MyHelper def self.dispatch_job(job = {}) end end class MyWorker def run MyHelper.dispatch_job(...) end end 2. Use a module and include the method into whatever class I need this functionality module MyHelper def self.dispatch_job(job = {}) end end class MyWorker include MyHelper def run dispatch_job(...) end end 3. Other possibilities I don't know yet ... The first one is more Java-like, but I'm not sure if the second one is really an appropriate use of Ruby's modules.

    Read the article

  • Interrupting `while loop` with keyboard in Cython

    - by linello
    I want to be able to interrupt a long function with cython, using the usual CTRL+C interrupt command. My C++ long function is repeatedly called inside a while loop from Cython code, but I want to be able, during the loop, to send an "interrupt" and block the while loop. The interrupt also should wait the longFunction() to finish, so that no data are lost or kept in unknown status. This is one of my first implementation, which obviously doesn't work: computed=0; print "Computing long function..." while ( computed==0 ): try: computed = self.thisptr.aLongFunction() except (KeyboardInterrupt, SystemExit): computed=1 print '\n! Received keyboard interrupt.\n' break; (p.s. self.thisptr is the pointer to the current class which implements aLongFunction() )

    Read the article

  • Custom nib UITableViewCell height

    - by Chuck
    I've created a custom UITableViewCell in IB, linked it to the root view controller's property for it, and set it up in CellForRowAtIndexPath. But the height of my drawn cells doesn't match what I setup in IB, advice? Here's some screenshots and the code. - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *AddressCellIdentifier = @"AddressCellIdent"; UITableViewCell *thisCell = [tableView dequeueReusableCellWithIdentifier:AddressCellIdentifier]; if (thisCell == nil) { [[NSBundle mainBundle] loadNibNamed:@"AddressCell" owner:self options:nil]; thisCell = addressCell; self.addressCell = nil; } return thisCell ; } addressCell is a @property (nonatomic, assign) IBOutlet UITableViewCell *addressCell;, and is linked up in IB to the file's owner (the table view controller). I'm using the example from Apple's table view programming guide.

    Read the article

  • iPhone memory management (with specific examples/questions)

    - by donkim
    Hey all. I know this question's been asked but I still don't have a clear picture of memory management in Objective-C. I feel like I have a pretty good grasp of it, but I'd still like some correct answers for the following code. I have a series of examples that I'd love for someone(s) to clarify. Setting a value for an instance variable. Say I have an NSMutableArray variable. In my class, when I initialize it, do I need to call a retain on it? Do I do fooArray = [[[NSMutableArray alloc] init] retain]; or fooArray = [[NSMutableArray alloc] init]; Does doing [[NSMutableArray alloc] init] already set the retain count to 1, so I wouldn't need to call retain on it? On the other hand, if I called a method that I know returns an autoreleased object, I would for sure have to call retain on it, right? Like so: fooString = [[NSString stringWithFormat:@"%d items", someInt] retain]; Properties. I ask about the retain because I'm a bit confused about how @property's automatic setter works. If I had set fooArray to be a @property with retain set, Objective-C will automatically create the following setter, right? - (void)setFooArray:(NSMutableArray *)anArray { [fooArray release]; fooArray = [anArray retain]; } So, if I had code like this: self.fooArray = [[NSMutableArray alloc] init]; (which I believe is valid code), Objective-C creates a setter method that calls retain on the value assigned to fooArray. In this case, will the retain count actually be 2? Correct way of setting a value of a property. I know there are questions on this and (possibly) debates, but which is the right way to set a @property? This? self.fooArray = [[NSMutableArray alloc] init]; Or this? NSMutableArray *anArray = [[NSMutableArray alloc] init]; self.fooArray = anArray; [anArray release]; I'd love to get some clarification on these examples. Thanks!

    Read the article

  • ModelName(django.contrib.auth.models.User) vs ModelName(models.Model)

    - by amr.negm
    I am developing a django project. I created some apps, some of those are related to User model, for instance, I have a feeds app that handles user feeds, and another app that deals with extra user data like age, contacts, and friends. for each of these, I created a table that should be connected to the User model, which I using for storing and authenticating users. I found two ways to deal with this issue. One, is through extending User model to be like this: ModelName(User): friends = models.ManyToMany('self') ..... Two, is through adding a foreign key to the new table like this: ModelName(models.Model): user = models.ForeignKey(User, unique=True) friends = friends = models.ManyToMany('self') ...... I can't decide which to use in which case. in other words, what are the core differences between both?

    Read the article

  • Finding the next record in the database with Active Record

    - by ericraio
    So I have my rails application and I have blog posts in my application. For starters I am on rails 2.3.5 and Ruby 1.8.7 For the show page, I am required to give a prev/next link to the prev/next blog post. The catch is that I need to find the next blog where the language column in the database is equal to 'eng'. I had started writing this out in my model and it works but of course this will just find the prev/next record in the database no matter what the language is specified in the column and it will break when the record is not found. def next(lang='eng') BlogEntry.find(self.id - 1) end def prev(lang='eng') BlogEntry.find(self.id + 1) end

    Read the article

  • Core Data Predicate To Many

    - by Vikings
    I have a core data model that has a one to many relationship, there is a category, and it can contain many subcategories. Category <---- Subcategory I am trying to perform a fetch that checks if a particular Category contains a Subcategory with a particular name. Let's say I have two categories below, I want to fetch to see if there are any subcategories name "Apple" in the Category named "Fruits". Vetegables - Carrot - Lettuce Fruits - Apple - Orange - Pear Code: - (SubCategory *)searchForSubCategoryWithName:(NSString *)subCategory inCategory:(Category *)category { NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"SubCategory" inManagedObjectContext:self.beer.managedObjectContext]; [fetchRequest setEntity:entity]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"name == [c] %@", subCategory]; [fetchRequest setPredicate:predicate]; NSError *error; NSArray *fetchedObjects = [self.beer.managedObjectContext executeFetchRequest:fetchRequest error:&error]; if (fetchedObjects != nil && fetchedObjects.count > 0) { return [fetchedObjects objectAtIndex:0]; } else { return nil; } }

    Read the article

  • Why isn't this simple test class's method inherited in Ruby?

    - by Kevin Bannister
    Consider this very simple logging class: class MockLog def self.log_stub_method(*args) args.each do |a| define_method "#{a}" do |msg| t = Time.now.strftime("%Y-%m-%d %H:%M:%S") $stderr.puts "[#{a.upcase}] \u00bb [#{t}] #{msg}" end end end log_stub_method :fatal, :error, :warn, :info, :debug end Let's add logging to all our classes: class Module def has_logging() class_eval { @log = MockLog.new def log self.class.instance_variable_get :@log end } end end Now, why doesn't this work? class Foo has_logging end Foo.new.log.nil? # => false, as expected class Bar < Foo end Bar.new.log.nil? # => true?! Why wasn't the `log` method inherited?

    Read the article

  • Problems using the Razor model when creating my knockout ViewModel

    - by Emil Kantis
    I'm having problems with using the Model in a javascript call when setting up my knockout VM.. @model List<AdminGui.Models.Domain> <script src="http://ajax.aspnetcdn.com/ajax/knockout/knockout-2.2.1.js" type="text/javascript"></script> <script type="text/javascript"> function ViewModel() { var self = this; self.domains = ko.observableArray( ko.utils.arrayMap(@Model, function(item) { return new Domain(item.guid, item.description, item.namespaces); })); } I get a syntax error on @Model in the ko.utils.arrayMap call. I suspect it might be my Razor-fu that is lacking... :)

    Read the article

  • Error 500 on template.render() with jinja2

    - by Asperitas
    I am working on playing with some Python to create a webapp. At first I put the HTML in a string, using %s to fill certain elements. That all worked perfectly. Now I want to put the HTML in a template, so I followed this tutorial. My code looks like this (I deleted irrelevant code for this error): import codecs import cgi import os import jinja2 jinja_environment = jinja2.Environment(loader=jinja2.FileSystemLoader(os.path.join(os.path.dirname(__file__)))) class Rot13Handler(webapp2.RequestHandler): def get(self): template = jinja_environment.get_template('rot13.html') self.response.out.write(template.render({'text': ''})) When I replace just template.render({'text': ''}) a random string, the program works fine. I did add the latest jinja2 library to my app.yaml, and naturally my rot13.html does exist with the {{ text }} added. So could anyone please help me in the right direction? I don't know why it's going wrong.

    Read the article

  • UITableViewController setting delegates and datasource

    - by the_great_monkey
    Hi iOS gurus, I'm a little bit confused about UITableViewController... As far as I concern they are typically the delegate and datasource of the UITableView (although it can be made such that they are different). However in some cases, like when embedding a UITableViewController in a UITabBarViewController in Interface Builder, we initiate our table view controller in IB. Therefore in my understanding, the default initialiser is being called. But in this case, I have this piece of code: @interface Settings : UITableViewController { } And in the IB I see that the delegate and datasource of the UITableView is hooked up to this class. My question is, why is it that we don't need to explicitly say that it is following: @interface Settings : UITableViewController <UITableViewDelegate, UITableViewDataSource> { } And in the .m file: - (void)viewDidLoad { [super viewDidLoad]; [tableView setDelegate:self]; [tableView setDataSource:self]; } I have indeed stumbled upon some cases where I have to explicitly code the above a few times to make something work. Although it is still a mystery for me as of why it is needed...

    Read the article

  • Why Can't I import a UITableViewCell subclass ? That's weird....

    - by user320064
    It's like this, I created a UITableViewCell subclass called NewsItemCell, then I wanna use it in my FirstViewController.m, then I tried to import it, but the compiler keeps telling me this Below is my code, it is driving me mad, thank you if you can help. import "NewsItemCell.h" import "FirstViewController.h" @implementation FirstViewController @synthesize computers; (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"NewsItemCellIdentifier"; NewsItemcell *cell = (NewsItemcell *)[tableView dequeueReusableCellWithIdentifier: CellIdentifier]; if (cell == nil) { NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"NewsItemCell" owner:self options:nil]; for (id oneObject in nib) if ([oneObject isKindOfClass:[NewsItemcell class]]) cell = (NewsItemcell *)oneObject; } NSUInteger row = [indexPath row]; NSDictionary *rowData = [self.computers objectAtIndex:row]; cell.newsTitle.text = [rowData objectForKey:@"Color"]; cell.newsDate.text = [rowData objectForKey:@"Name"]; return cell; } Jason

    Read the article

  • How to save state of the app when app terminates?

    - by user164589
    Hi guys. I am trying to save the app state by encoding when the app terminates. I've found the solution related this issue. But I don't know how to use. I am really trying to make encoding and decoding like this: http://cocoaheads.byu.edu/wiki/nscoding in CustomObject.h @interface CustomObject : NSObject <NSCoding> { NSArray *someArray; } in CustomObject.m @implementation CustomObject // Other method implementations here - (void) encodeWithCoder:(NSCoder*)encoder { [encoder encodeObject:someArray forKey:@"someArray"]; } - (id) initWithCoder:(NSCoder*)decoder { if (self = [super init]) { someArray = [[decoder decodeObjectForKey:@"someArray"] retain]; } return self; } @end My object to save is another NSArray. Not "someArray" in CustomObject. We call it that "MySaveObject". I want to pass "MySaveObject" to "someArray" in CustomObject. Actually I don't know how to encode "MySaveObject" and to pass to "someArray" in CustomObject. Thanks in advance.

    Read the article

  • fast scrolling background

    - by Andre
    i want a game that scrolls the background in a similar way to a UItableView. I solved it with a timer that moves the background up and brings another copy of the same picture up if (bg1.center.y <= - self.view.bounds.size.height/2 ) { bg1.center = CGPointMake(bg1.center.x, 690); } if (bg2.center.y <= - self.view.bounds.size.height/2 ) { bg2.center = CGPointMake(bg2.center.x, 690); bg1.center = CGPointMake(bg1.center.x, bg1.center.y - movement); bg2.center = CGPointMake(bg2.center.x, bg2.center.y - movement); But the faster i move the pictures the more problems occur: There are appearing gaps between the backgrounds and they are getting biggiger the faster i move them! movement is defined by the speed of swiping over the screen Any idea to solve that?

    Read the article

< Previous Page | 193 194 195 196 197 198 199 200 201 202 203 204  | Next Page >