Apr 22

For a project I’m currently working on, I needed to show a ‘Load more’ cell when there were >25 results, this is not a basic 1-2-3 on how to fill tablecells with data, so below code is assuming you already have that and it’s left out

In my code I will fetch a maximum of 25 results (which can be less) and stick this into an array. If the array count is 25, we have to add an extra cell, to do this we increase the count by one:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
        NSLog(@"Setting numberOfRowsInSection to %i",[self.localJsonArray count]);
        if ( [jsonArray count] < 25 ) {
                return [self.localJsonArray count];
        } else {
                return [self.localJsonArray count] + 1;

Next we populate the tablecells, we fill it with data from the index, and we look if we’re still working with data or are at the +1 we defined above:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
        static NSString *CellIdentifier = @"Cell";
        ImageCell *cell = (ImageCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
        if (indexPath.row != [localJsonArray count] ) { // As long as we haven’t reached the +1 yet in the count, we populate the cell like normal
                if (cell == nil) {
                        cell = [[[ImageCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
                NSDictionary *itemAtIndex = (NSDictionary *)[self.localJsonArray objectAtIndex:indexPath.row];
                [cell setData:itemAtIndex];
        } // Ok, all done for filling the normal cells, next we probaply reach the +1 index, which doesn’t contain anything yet
        if ( [jsonArray count] == 25 ) { // Only call this if the array count is 25
                if(indexPath.row == [localJsonArray count] ) { // Here we check if we reached the end of the index, so the +1 row
                        if (cell == nil) {
                                cell = [[[ImageCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
                        // Reset previous content of the cell, I have these defined in a UITableCell subclass, change them where needed
                        cell.cellBackground.image = nil;
                        cell.titleLabel.text = nil;
                        // Here we create the ‘Load more’ cell
                        loadMore =[[UILabel alloc]initWithFrame: CGRectMake(0,0,362,73)];
                        loadMore.textColor = [UIColor blackColor];
                        loadMore.highlightedTextColor = [UIColor darkGrayColor];
                        loadMore.backgroundColor = [UIColor clearColor];
                        loadMore.font=[UIFont fontWithName:@"Verdana" size:20];
                        loadMore.font=[UIFont boldSystemFontOfSize:20];
                        loadMore.text=@"Load More..";
                        [cell addSubview:loadMore];
        return cell;

And voila, cell #26 is the ‘Load more’ cell, next we start detecting if it’s that cell that’s being selected:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
        if ( [jsonArray count] == 25 ) { //  Only call the function if we have 25 results in the array
                if (indexPath.row == [localJsonArray count] ) {
                        NSLog(@"Load More requested"); // Add a function here to add more data to your array and reload the content
                } else {
                       NSLog(@"Normal cell selected"); // Add here your normal didSelectRowAtIndexPath code
        } else {
                       NSLog(@"Normal cell selected with < 25 results"); //  Add here your normal didSelectRowAtIndexPath code

Note that I’m working with 2 arrays here, jsonArray and localJsonArray, the jsonArray is what I fill with new results, i.e. 1-25 26-50, the localJsonArray is what’s being filled more and more, so on every ‘Load More’ selection, the localJsonArray will grow with +25 if there’s >= 25 items to load.

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Apr 12

In general try to avoid to set too many global variables, instead use local class variables instead to keep things as less complicated as possible.
But sometimes it can come in handy to set variables in your app that you can address from all your classes.

The easiest way to do this, is to use your AppDelegate class for this. You can just include your AppDelegate where needed and address the functions and variables that are in there.

First, define the variables in the AppDelegate’s .h and .m files:

#import <UIKit/UIKit.h>

@interface My_ApplicationAppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate> {
    UIWindow *window;
    NSInteger *myGlobalInteger;
@property (nonatomic, assign) NSInteger *myGlobalInteger;

#import "My_ApplicationAppDelegate.h"
@implementation My_ApplicationAppDelegate
@synthesize window,myGlobalInteger;

To access these global variables from and to your AppDelegate class, first include your AppDelegate in the .m file of the class where you need it.

#import "My_ApplicationAppDelegate.h"

And then define the following in the function where you need to access the variable:

- (void)myFunction {
        My_ApplicationAppDelegate *appDelegate = (My_ApplicationAppDelegate *)[[UIApplication sharedApplication] delegate];
        appDelegate.myGlobalInteger = 1;
        NSLog(@"The integer value is %i",myGlobalInteger);

And voila, you can access the myGlobalInteger value from everywhere where you allocate the My_ApplicationAppDelegate like shown above.

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Apr 06

Formatting a proper date string can be a bit tedious, I’ve tried to work with the time function available in C, but that didn’t work out very well due dates not getting converted properly to my locale (Dutch in my case).

After fiddeling quite a bit, it turned out that combining NSDateFormatter with NSLocale and NSDate would work the magic I needed for displaying a proper date in a UITableView.

NSDateFormatter *setDateLocale = [[NSDateFormatter alloc] init];
NSLocale *nl_NL = [[NSLocale alloc] initWithLocaleIdentifier:@"nl_NL"];
[setDateLocale setDateFormat:@"EEE, d MMM yyy"];
[setDateLocale setLocale:nl_NL];
NSDate *now = [[NSDate alloc] init];
NSString *FormattedYMD = [setDateLocale stringFromDate:now];
[nl_NL release];
[setDateLocale release];
[now release];

And voila, FormattedYMD now holds the current datestamp formatted as: ma, 6 apr 2010

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Apr 05

Now as it happens to be, I’m from The Netherlands and somehow Steve Jobs (or rather his marketing department) forgot to add our country to the known release dates (gives a certain feeling of Deja-Vu since the same happened with the iPhone).

While setting up a twitter account yesterday to post blog updates, I stumbled on two companies giving away free iPads. Basically if you tweet a post about it you enter the draw to win one.

In the left corner we have Webs.com, who are about to give away their 5th iPad today.

And in the right corner I just stumbled upon Ambrosia Software giving away 4 free iPads and a software pack on it.

Fine, now let’s win that iPad so I can start porting my already released KookJij app on it while the rest of the country awaits the official release :-)

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Apr 05

For one of my projects, I needed the makeiPhoneRefMovie executable which is normally only available on OSX. This program will make a .mov index file referencing various movies (.3gp, .m4v) for various available bandwidths and will compile under Linux (Tested on Debian and CentOS 5 64-bit), it’s based on the original source by Apple and some functions (mostly the OSSwapHostToBigInt32 unctions that aren’t known on Linux) merged together.

Extract and compile with cc -o makeiPhoneRefMovie -g makeiPhoneRefMovie.c


# ../makeiPhoneRefMovie
usage: ../makeiPhoneRefMovie foo-low.3gp foo-high.m4v foo-desktop.mov foo-ref.mov
     creates foo-ref.mov with a special-purpose iPhone ref movie
     the other files need not exist; they're just embedded as URLs
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Apr 04

Somehow, I was always struggling with the proper certificates, permissions, names, icons, etc. when building an app for either my testers or the app store.

iPhonedevelopertips.com has a very nice distribution build cheat sheet online.
Whenever I setup a new project for Ah-Hoc distribution or for Appstore distribution, I go over several steps in this document, it saves a lot of headaches on why XCode is complaining on missing certificates, provisioning profiles or why your just built app just won’t install on that tester’s iPhone.

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Apr 02

There’s a few methods to change your company name that shows up in new source files you add to your project.

To do it on a system-wide basis so it applies to all projects, open a terminal window, and type the following line (one line, no enters):

defaults write com.apple.Xcode PBXCustomTemplateMacroDefinitions ‘{ORGANIZATIONNAME="YourCompanyNameHere";}’

To do it on a per project basis so it applies only to files in your current project, right-click your project and select ‘Get info’

Get project info

Now select the ‘general’ tab and change the company name to what you’d like in the project files to show up.
Change company name

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