Saturday 26 January 2013

[iOS] RestKit Tutorial Code For Version 0.20

I was trying to follow the RestKit tutorial at

RayWenderlich's Intro to RestKit Tutorial

but encountered various problems due to significant changes in the version 0.20 RestKit.

After searching for solutions at stackoverflow as well as RestKit.org, I finally found the missing pieces and got the example code working with RestKit version 0.20.

Firstly, after adding "#import <RestKit/RestKit.h>" in AppDelegate.m, there was a missing header file error when compiling the app. I found the solution here in stackoverflow.

To resolve this, I need to pull in additional files by running the command below in RestKit directory:

git submodule update --init --recursive

The following is code I used in MasterViewController. You should be able to reuse the other code found in RayWenderlich's tutorial for Location.m, Location.m, Venue.m, and Venue.h.

One key resource that help me was the wiki entry for RKObjectMapping at Restkit.org below:

https://github.com/RestKit/RestKit/wiki/Object-mapping

 //  
 // MasterViewController.m  
 // CoffeeShop  
 //  
 //  
 // Copyright (c) 2013 uihelpers. All rights reserved.  
 //  
 #import "MasterViewController.h"  
 #import <RestKit/RestKit.h>  
 #import "Venue.h"  
 #import "Location.h"  
 #define kCLIENTID "REPLACE_WITH_OWN_ID"  
 #define kCLIENTSECRET "REPLACE_WITH_OWN_SECRET"  
 @interface MasterViewController () {  
   NSMutableArray *_objects;  
   NSArray *cafeArray;  
 }  
 @end  
 @implementation MasterViewController  
 - (void)awakeFromNib  
 {  
   [super awakeFromNib];  
 }  
 - (void)viewDidLoad  
 {  
   [super viewDidLoad];  
      // Do any additional setup after loading the view, typically from a nib.  
   self.navigationItem.leftBarButtonItem = self.editButtonItem;  
   UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(insertNewObject:)];  
   self.navigationItem.rightBarButtonItem = addButton;  
   NSURL *baseURL = [NSURL URLWithString:@"https://api.foursquare.com/v2"];  
   AFHTTPClient * client = [AFHTTPClient clientWithBaseURL:baseURL];  
   [client setDefaultHeader:@"Accept" value:RKMIMETypeJSON];  
   RKObjectManager *objectManager = [[RKObjectManager alloc] initWithHTTPClient:client];  
   RKObjectMapping *venueMapping = [RKObjectMapping mappingForClass:[Venue class]];  
   [venueMapping addAttributeMappingsFromDictionary:@{  
    @"name" : @"name"  
    }];  
   RKObjectMapping *locationMapping = [RKObjectMapping mappingForClass:[Location class]];  
   [locationMapping addAttributeMappingsFromDictionary:@{ @"address": @"address", @"city": @"city", @"country": @"country", @"crossStreet": @"crossStreet", @"postalCode": @"postalCode", @"state": @"state", @"distance": @"distance", @"lat": @"lat", @"lng": @"lng"}];  
   /*[venueMapping mapRelationship:@"location" withMapping:locationMapping];  
   [objectManager.mappingProvider setMapping:locationMapping forKeyPath:@"location"];*/  
   [venueMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"location" toKeyPath:@"location" withMapping:locationMapping]];  
   RKResponseDescriptor * responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:venueMapping  
                                           pathPattern:nil  
                                           keyPath:@"response.venues"  
                                           statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];  
   [objectManager addResponseDescriptor:responseDescriptor];  
   NSString *latLon = @"37.33,-122.03";  
   NSString *clientID = [NSString stringWithUTF8String:kCLIENTID];  
   NSString *clientSecret = [NSString stringWithUTF8String:kCLIENTSECRET];  
   NSDictionary *queryParams;  
   queryParams = [NSDictionary dictionaryWithObjectsAndKeys:latLon, @"ll", clientID, @"client_id", clientSecret, @"client_secret", @"coffee", @"query", @"20120602", @"v", nil];  
   [objectManager getObjectsAtPath:@"https://api.foursquare.com/v2/venues/search"  
              parameters:queryParams  
               success:^(RKObjectRequestOperation * operaton, RKMappingResult *mappingResult)  
    {  
      //NSLog(@"success: mappings: %@", mappingResult);  
      NSArray *result = [mappingResult array];  
      cafeArray = [mappingResult array];  
      for (Venue *item in result) {  
        NSLog(@"name=%@",item.name);  
        NSLog(@"name=%@",item.location.distance);  
      }  
      [self.tableView reloadData];  
    }  
               failure:^(RKObjectRequestOperation * operaton, NSError * error)  
    {  
      NSLog (@"failure: operation: %@ \n\nerror: %@", operaton, error);  
    }];  
 }  
 - (void)viewDidUnload  
 {  
   [super viewDidUnload];  
   // Release any retained subviews of the main view.  
 }  
 - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation  
 {  
   return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);  
 }  
 - (void)insertNewObject:(id)sender  
 {  
   if (!_objects) {  
     _objects = [[NSMutableArray alloc] init];  
   }  
   [_objects insertObject:[NSDate date] atIndex:0];  
   NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];  
   [self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];  
 }  
 #pragma mark - Table View  
 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView  
 {  
   return 1;  
 }  
 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section  
 {  
   return cafeArray.count;  
 }  
 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath  
 {  
   UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];  
   /*NSDate *object = [_objects objectAtIndex:indexPath.row];  
   cell.textLabel.text = [object description];*/  
   Venue *venueObject = [cafeArray objectAtIndex: indexPath.row];  
   cell.textLabel.text = [venueObject.name length] > 24 ? [venueObject.name substringToIndex:24] : venueObject.name;  
   cell.detailTextLabel.text = [NSString stringWithFormat:@"%.0fm", [venueObject.location.distance floatValue]];  
   return cell;  
 }  
 - (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath  
 {  
   // Return NO if you do not want the specified item to be editable.  
   return YES;  
 }  
 - (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath  
 {  
   if (editingStyle == UITableViewCellEditingStyleDelete) {  
     [_objects removeObjectAtIndex:indexPath.row];  
     [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];  
   } else if (editingStyle == UITableViewCellEditingStyleInsert) {  
     // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view.  
   }  
 }  
 /*  
 // Override to support rearranging the table view.  
 - (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath  
 {  
 }  
 */  
 /*  
 // Override to support conditional rearranging of the table view.  
 - (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath  
 {  
   // Return NO if you do not want the item to be re-orderable.  
   return YES;  
 }  
 */  
 @end  

Monday 21 January 2013

[iOS] Create static library

As mentioned in my earlier blog, 2 of my apps needed a pin challenge view. In order to share the code, it was better to create it as a library.

I managed to find a good base code in "PinView" at guicocoa.

However, I needed to enhance it to include a custom button on lower left corner as well as make the "delete(x)" key same color as other keys. I'll leave those code details for another posting.

Step 1. Download pinview at git

Step 2.  Below is the directory structure of "PinView" sample app, where the PinView code will be under "pinview" directory. Make a backup of this directory and save it at another location.








Step 3. open the SampleApp project by clicking on the SampleApp.xcodeproj.

Step 4. In order to create a clean directory structure, we need to first delete the pinview directory. Ensure "Move to Trash" option is selected in the confirmation dialog.


Ensure the "Move to Trash" option is selected.

Step 5. Create a new "Cocoa Touch Static Library" target, by selecting "File > New > Target".

Step 6. I maintained the "pinview" name.

Steps 7. Xcode generated some code for us, which we don't need. So, delete them and choose the "Move to Trash" option.

Steps 8. Notice the pinview directory now only contains the pinview-Prefix.pch.









Step 9. Copy all the code you backed up in Step 2. and paste them into pinview directory.
 Next, in xcode, add all the files under pinview directory.

























Step 10. Next, add the new library by selecting "SampleApp" under Targets, > Build Phase > Link Binary With Libraries > "+". Next, select the libpinview.a and click "Add".


























Now, you are ready to run the SampleApp.

[iOS] Need to create a Pin Challenge View static library for sharing

My iOS project requires a Pin Challenge View as seen below. I need to make it into a module that can be shared across different iPhone apps.

I found the links below useful to me:

1. http://www.clintharris.net/2009/iphone-app-shared-libraries/
Cross reference library as separate xcode project

2. http://blog.stormyprods.com/2008/11/using-static-libraries-with-iphone-sdk.html
Create static library


Sunday 20 January 2013

Implementing a credit card reader - Initial study

I'm currently studying the EMV standard at http://www.emvco.com/specifications.aspx?id=223 in order to implement a card reader module on iOS.

The following resources have been very useful to me:

i) http://khuong.vn/Papers/EMVThesis.pdf ( good starting point - high level understanding of EMV)

ii) EMV_v4.3_Book_1_ICC_to_Terminal_Interface

iii) EMV_v4.3_Book_3_Application_Specification