iPhone code snippets

To go through this tutorial, a programming knowledge in Objective C and Hypertext Transfer Protocol (HTTP) is preferred.

Technical requirements:

Mac OS X version 10.5 Leopard or later
Xcode 3.1
iPhone 3.1 SDK

IDrive EVS Photo Backup for iPhone

Photo Backup is an iPhone-based application, which allows the user to:

• Upload photos from Photo library to IDrive account
• Download photos to Photo library from IDrive account
• Delete the file(s) in IDrive account
• Search for the file(s) in IDrive account

This is how it works:

To begin with, download and unzip the source code. Now, open the source using Xcode by double-clicking on PhotoBackup.xcodeproj file found in the project source folder.

The sample Photo Backup application, puts up login screen, with username and password fields as shown below:

(Sign up with IDrive and provide user credentials in Photo Backup application.)



Enter the registered username and password and click the Login button.
NSURLRequest object for login request is created and executed in WebService class.

Below is the code snippet for WebService class: postParameter = [NSString stringWithFormat:sIDLOperationTypeAccountValidatePar,emailText,passwordText]; urlString = sIDLOperationTypeAccountValidate; requestURL = [NSURL URLWithString:urlString]; [request setHTTPMethod:@"POST"]; [request addValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"]; [request setHTTPBody:[postParameter dataUsingEncoding: NSUTF8StringEncoding]]; NSHTTPURLResponse * response = nil; NSError *error = nil ; NSData * data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
After the successful validation, enter the private encryption key as shown below:



On successful confirmation, a screen will be displayed with Backup, File / folder listing and Search options as shown below:

Backup photos from Photo library to IDrive account

Select the image that you wish to backup from the image list. The application transfers the selected image file to your IDrive account. The below screen displays backup operation in progress.



Once the image is selected form the imagePicker, the image file is created under
"Documents/PhotoBackup/Photos folder" path. This path will be used by the WebService object for creating the backup request object.

Below is the code snippet of WebService class, which makes image Backup request: [request setHTTPMethod:@"POST"]; NSString *stringBoundary = [NSString stringWithString:@"AaB03x"]; NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",stringBoundary]; [request addValue:contentType forHTTPHeaderField: @"Content-Type"]; NSMutableData *body = [NSMutableData data]; NSMutableDictionary *post = [NSMutableDictionary dictionaryWithDictionary:scriptInfo]; [post removeObjectForKey:RequestType]; NSEnumerator *e = [post keyEnumerator]; NSString *key; //File path for photos NSString *folderPath = [IDLFactory photosDirectoryPath] ; NSArray *inPathsArray = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:folderPath error:nil]; NSString *filePath = [inPathsArray objectAtIndex:0]; NSString *absolutepath = [folderPath stringByAppendingPathComponent: filePath] ; [body appendData:[[NSString stringWithFormat:@"--%@\r\n",stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]]; /* This while loop run's through all parameters given for photo backup URL(uid,pwd,pvtkey) except uploadfile parameter. uploadfile contains the image file path.Which should be appended as image data,with the format as specified below */ while (key = [e nextObject]) { if (![key isEqualToString:UpLoadPath]) { [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"%@", key,REQUEST_DELIMITER] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[post objectForKey:key] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]]; } } [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"uploadFile\"; filename=\"%@\"\r\n",filePath] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithFormat:@"Content-Type: application/octet-stream%@",REQUEST_DELIMITER] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[ NSData dataWithContentsOfFile:absolutepath]]; [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]]; [request setHTTPBody:body]; [IDLFactory cleanupSupportingFiles] ; NSHTTPURLResponse * response = nil; NSError *error = nil ; NSData * data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

Files / Folders Listing

Traverse through the file hierarchy by selecting folder in the file / folder list. You can either “Download” or “Delete” the files that are listed.



File / folder listing response will be in XML format, IDLParser class parse and saves the data in IDLFileAttribute class. Which is later read by IDLTableViewController class (tableview datasource). IDLFileListViewController class handles folder navigation and the file information screen related modules. IDLFileAttribute is a modal class which handles IDLFileInfo and IDLFolderInfo object creation depending upon parsed data.

Below is the code snippet of WebService class, which makes file / folder listing request: postParameter = [NSString stringWithFormat:sIDLOperationTypeRemoteListingPar,emailText,passwordText,pvtkey,fileName]; urlString = sIDLOperationTypeRemoteListing; requestURL = [NSURL URLWithString:urlString]; [request setHTTPMethod:@"POST"]; [request addValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"]; [request setHTTPBody:[postParameter dataUsingEncoding: NSUTF8StringEncoding]]; NSHTTPURLResponse * response = nil; NSError *error = nil ; NSData * data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

Download photos to Photo library from IDrive account

To perform Restore operation, click the Restore button as shown below:



IDLFileListViewController class handles the Restore and Delete operations. NSURLRequest object for image restore and file Deletion from IDrive account is created and executed in WebService class.

Below is the code snippet of WebService class, which makes image Restore request: postParameter = [NSString stringWithFormat:sIDLOperationTypeRemoteListingPar,emailText,passwordText,pvtkey,fileName]; urlString = sIDLOperationTypeRestore; requestURL = [NSURL URLWithString:urlString]; [request setHTTPMethod:@"POST"]; [request addValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"]; [request setHTTPBody:[postParameter dataUsingEncoding: NSUTF8StringEncoding]]; NSHTTPURLResponse * response = nil; NSError *error = nil ; NSData * data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

Delete the file(s) in IDrive account

To perform the Delete operation, click the Delete button as shown below:



Below is the code snippet of WebService class, which makes file Deletion request: postParameter = [NSString stringWithFormat:sIDLOperationTypeDeletePar,emailText,passwordText,pvtkey,fileName]; urlString = sIDLOperationTypeDelete; requestURL = [NSURL URLWithString:urlString]; [request setHTTPMethod:@"POST"]; [request addValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"]; [request setHTTPBody:[postParameter dataUsingEncoding: NSUTF8StringEncoding]]; NSHTTPURLResponse * response = nil; NSError *error = nil ; NSData * data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

Search for the file(s) in IDrive account

To perform the search operation, enter the search phrase as shown below:



Based on the search phrase the search results will be displayed as below:



Search operation response will be in XML format, IDLParser class parse and saves the data in IDLFileAttribute class, which is later read by IDLTableViewController class (tableview datasource).

Below is the code snippet of WebService class, which makes search request: searchPath = [scriptInfo objectForKey:SearchKey]; postParameter = [NSString stringWithFormat:sIDLOperationTypeSearchPar,emailText,passwordText,pvtkey,fileName,searchPath]; urlString = sIDLOperationTypeSearch; requestURL = [NSURL URLWithString:urlString]; [request setHTTPMethod:@"POST"]; [request addValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"]; [request setHTTPBody:[postParameter dataUsingEncoding: NSUTF8StringEncoding]]; NSHTTPURLResponse * response = nil; NSError *error = nil ; NSData * data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];