Arc Reactor

App Extensions

Mon, 09 Mar 2015 09:55:23 +0000

I created two iOS App extension for my App Take Note

A share extension is a separate process to your App

// Example showing an App that accepts `Text` and `URL`
override func didSelectPost() {
  if let item = extensionContext?.inputItems[0] as? NSExtensionItem {

  //            println("extension item \(item)")
      if let attachments = item.attachments as? [NSItemProvider] {

          var validAttachments = attachments.filter({ $0.hasItemConformingToTypeIdentifier("public.url") || $0.hasItemConformingToTypeIdentifier("public.plain-text")  })
          for (i, provider: NSItemProvider) in enumerate(validAttachments) {

              if provider.hasItemConformingToTypeIdentifier("public.url") {

                  provider.loadItemForTypeIdentifier("public.url", options: nil) { decoder, error in
                      if let url = decoder as? NSURL {
                          text = "\(text) - \(url.absoluteString!)"
                      }

                      if i+1 == validAttachments.count {
                          self.send(text)
                      }
                  }

              } else if provider.hasItemConformingToTypeIdentifier("public.plain-text") {
                  provider.loadItemForTypeIdentifier("public.plain-text", options: nil) { decoder, error in
                      if let string = decoder as? String {

                          if self.contentText != string {
                              text = "\(text) - \(string)"
                          }
                      }

                      if i+1 == validAttachments.count {
                          self.send(text)
                      }
                  }
              }
          }

      }
  } else {
      send(text)
  }
}

func send(text: String) {
    // Write `text` into shared container here

    // Complete extension transaction
    self.extensionContext!.completeRequestReturningItems([], completionHandler: nil)
}

A today widget needs to display some useful information to a user and will probably also open the App with context on tap.

Because you probably can’t just read your Apps data store, your App will need to write to a shared container which can be read by a today widget.

// Open App with custom URL scheme
if let url = NSURL(string: "take-notes://text") {
    self.extensionContext?.openURL(url, completionHandler:nil)
}

Content Management Systems

Tue, 14 Oct 2014 23:23:23 +0000

Content management systems (CMS) are standard place for blogs and websites. Examples include Wordpress, Refinery to name a few.

CMS aim to solve the problem with creating and maintaining a website, and they have certainly made websites more widely available and accessible which is great.

As a developer, however, CMS rarely cover all the needs of a website as we approach more custom and unique websites and pages end up with more code than CMS flexibility. And whilst I don’t have an issue with changing code to update a website, that kind of limits updates to technical users.

I think Content management systems have room to grow and should support a minimal set of features.

Desirable Qualities

Easy setup
Easy to Maintain
Internationalisation
CDN Friendly
Caching
Search Engine Friendly
Good Design and User Experience
Scalable
Extendable

I haven’t found a solution that covers these points adequately, and I don’t really want to build my own. (or do I?)

CMS-free

As a developer compiling a website to static files appeals to me a lot.

Jekyll and other static website generators are becoming popular as static content can easily and cheaply be hosted, along with reduced server complexity and ease of scaling.

This has its issues and probably wouldn’t suggest this to a client just yet. Although Prose.io is getting pretty close to client friendly.

Swift & Objective-C

Mon, 06 Oct 2014 23:23:23 +0000

You can include and use CocoaPods in a swift project.

Objective-C from Swift

To use Objective-C code in swift you need to setup a bridging header to make the Objective-C code visible to Swift.

Add header file to your project (eg. Bridging-Header.h). Set the bridging header in the Build Setings (eg. YourApp/BridgingHeader.h). Then add #includes into the bridging header.

#import <AFNetworking/AFNetworking.h>

Swift from Objective-C

XCode generates a header for you to include, named after your project ProjectName-Swift.h

If a swift class doesn’t subclass an Objective-C object then the Swift class needs to be marked @objc

@objc class YourObject {
  // ...
}

Further

Dates

Sat, 04 Oct 2014 23:23:23 +0000

For date portability between server and client, and between timezones, it is best to store times and dates in UTC (GMT +0) and then convert them to the user timezone for displaying. Dates should be formatted in ISO 8601 2014-10-04T23:23:23.000Z

Objective-C

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

dateFormatter.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
dateFormatter.timeZone = [NSTimeZone timeZoneWithAbbreviation:@"UTC"];
dateFormatter.dateFormat = @"yyyy-MM-dd'T'HH:mm:ssZZZZZ";

// NSDate from NSString
NSDate *date = [dateFormatter dateFromString:"2014-10-04T23:23:23.000Z"];

// NSString from NSDate
NSString *string = [dateFormatter stringFromDate:date];

Swift

let dateFormatter = NSDateFormatter()

dateFormatter.locale = NSLocale(localeIdentifier:"en_US_POSIX")
dateFormatter.timeZone = NSTimeZone(name:"UTC")
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZZZ"

// NSDate from NSString
if let date = dateFormatter.dateFromString("2014-10-04T23:23:23.000Z") {

    // String from NSDate
    let string = dateFormatter.stringFromDate(date)
}

Ruby

# String from Time
string = Time.now.utc.iso8601

# Time from String
time = Time.iso8601("2014-10-04T23:23:23.000Z")

Javascript

var date = new Date();
// String from Date
var string = date.toISOString();

// Date from String
date = Date.parse("2014-10-04T23:23:23.000Z")

Java

SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZZZZZ");

Date date = format.parse(string);

String string = formatter.format(date);

Push Notifications

Thu, 02 Oct 2014 23:23:23 +0000

Notifications can contain, a message, a badge, have a sound effect, contain custom json, or just indicate new content.

iOS

This is the basic App delegate methods you need to implement.

// Register for user notifications
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
  [[UIApplication sharedApplication] registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:(UIUserNotificationTypeSound | UIUserNotificationTypeAlert | UIUserNotificationTypeBadge) categories:nil]];
else
  [[UIApplication sharedApplication] registerForRemoteNotificationTypes:(UIRemoteNotificationTypeAlert | UIRemoteNotificationTypeBadge | UIRemoteNotificationTypeSound)];


// Required app delegate method
- (void)application:(UIApplication *)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken
{
    NSLog(@"deviceToken: %@", deviceToken);
    // Register the device token with a webservice
}

// Required app delegate method
- (void)application:(UIApplication *)application didFailToRegisterForRemoteNotificationsWithError:(NSError *)error
{
    NSLog(@"Error: %@", error);
}

iOS 8

iOS8 introduced content only notifications which have taken the place of remote notifications. Content notifications can be utilised to wake your App (whilst in the background) and check for new content.

First add remote-notification to your Info.plist in the UIBackgroundModes array.

// Register for content notifications
[[UIApplication sharedApplication] registerForRemoteNotifications];

// New app delegate method
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))handler
{
    // Check with your server if there's new content

    /*
     * Note: you have 30 seconds to do your work and
     * call the completion handler
     */

    UIBackgroundFetchResult result = UIBackgroundFetchResultNoData;
    // You must then call the completion handler
    if(data)
      result = UIBackgroundFetchResultNewData;
    else if(error)
      result = UIBackgroundFetchResultFailed;
    handler(reusult);
}

The OS will track how long you take in application:didReceiveRemoteNotification:fetchCompletionHandler: and Apps which use significant power may not be woken up for further notifications.