Developing with Objective Pascal

Contents

Introduction

Adding support for iCloud to your iOS and OS X apps makes sense in many cases, but you may also want to consider adding support for an alternative like Dropbox when it's likely that some users will want to be able to share files with unsupported platforms. These notes describe how to do that.

Requirements

• Free Pascal compilers for i386 and ARM. Installers for FPC 2.6.2 can be downloaded from here.

• Dropbox SDKs for iOS and/or OS X, available from here:

  https://www.dropbox.com/developers/reference/sdk

• Latest Objective C header parser and Dropbox input files, available from here:

  iOS_6_Parsing_Status.html

Get the SDK examples working

1. Before you do anything else, make sure you can get the Dropbox SDK Objective C example programs working. Both the iOS and OS X SDKs include a DBRoulette example, which is a simple photo viewing app that downloads photos from the user's storage area for that app on the Dropbox server.

2. Open one of the example projects in Xcode and run it (Product | Run). You'll get an error message that you haven't set the app key yet. To obtain an app key, log into your Dropbox account and create one:

   https://www.dropbox.com/developers/apps

   In iCloud terms, a Dropbox app key is similar to an iCloud "entitlement bundle identifier". In both cases, they can be used for more than one app that need to share the same files in the cloud. For example, you might have a lite version of your app and a full version - both could share the same app key/identifier so that a user who upgrades to the full version can continue to use files from the lite version. In our case, you can use the same app key for both the iOS and OS X example programs.

   Note that app names need to be unique - if the Dropbox site indicates that a name is already taken, try adding your initials to the app name.

3. With both example programs, change the appKey, appSecret and root where indicated in the app delegate code. Also change the CFBundleURLSchemes key in the project's DBRoulette-Info.plist file. More information and an overview is here:

   https://www.dropbox.com/developers/start

   Note: Starting with the Setup step, make sure you have iOS selected from the dropdown menu.

Parse the SDK header files

iOS_5_Parsing_Status.html

Get the Pascal example working

Test6_DBiOS.zip

This is the start of a Pascal example program adapted from the iOS version of DBRoulette.

The Pascal example program can log in and log out of your Dropbox account. The Objective Pascal code is just a transliteration of the original Objective C code in DBRouletteAppDelegate.m and a bit from RootViewController.m. Adapting the remaining code in PhotoViewController.m that actually downloads the photos is left as an exercise for the reader.

To compile the Pascal example, you will need to do the following:

• Open Test6_DBiOS.xcodeproj in Xcode 4.2 or later.

• Change appKey and appSecret where indicated in Test6_DBiOS_AppDelegateU.pas. Also change the CFBundleURLSchemes key in the project's Test6_DBiOS-Info.plist file.

• On the project's Build Settings tab, check the path in the FPC_COMMON setting's -Ff switch to make sure it points to where you unzipped the Dropbox iOS SDK.

• Check the path in the FPC_ARM_UNITS and FPC_SIM_UNITS settings' -Fu switch to make sure they point to where your iPhoneAll.o, Dropbox_iOS.o, etc. files are located.

macpgmr (at) fastermac (dot) net

First posted April 15, 2012; last edited May 9, 2013.