Using Google Reader API and OAuth in iPhone app - iphone

Question

I want to make an app that uses on the Google Reader API. But I'm finding out that there isn't an offical API for it - is there a problem using the unofficial API, in terms of App Store guidelines/approval? Would other apps (Reeder, etc) use this?
Also what is the best method for logging in? Is OAuth the preffered method? Is using Janrain a good idea?

Answer 1

Frankly Apple doesn't care if you use Google's unofficial API.
I worked for a customer on a RSS reader app that used Google Reader for syncing. We didn't use OAuth but the standard HTTP login which returns you a cookie where you'll have to extract a token from to use in consecutive calls to the various reader URLs.
I can post you the login code from my (old) proof of concept app.
It uses ASIHTTP and some custom string categories. The idea is to send a login request, get the response and extract the session ID/auth code from the response's cookie header. Then you can use that session ID/auth code for consecutive calls.
#pragma mark -
#pragma mark login
//this is your sessionID token you get from the login
//use this in consecutive calls to google reader
//this method returns you the header string you have to add to your request
//[request addRequestHeader: #"Cookie" value: [self sidHeader]];
- (NSString *) sidHeader
{
return [NSString stringWithFormat: #"SID=%#", [self sid]];
}
- (NSString *) authHeader
{
return [NSString stringWithFormat: #"GoogleLogin auth=%#",[self auth]];
}
//login to your google account and get the session ID
- (void) login
{
NSString *username = #"my.googlelogin#gmail.com";
NSString *password = #"mypassword123";
NSString *loginUrl = #"https://www.google.com/accounts/ClientLogin?client=NNW-Mac";
NSString *source = #"NNW-Mac"; //let's fake NetNewsWire
NSString *continueUrl = #"http://www.google.com";
ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:[NSURL URLWithString: loginUrl]]; // log in & get cookies
[request addRequestHeader: #"User-Agent" value: #"NetNewsWire/3.2b25 (Mac OS X; http://www.newsgator.com/Individuals/NetNewsWire/)"];
[request setPostValue: username forKey: #"Email"];
[request setPostValue: password forKey: #"Passwd"];
[request setPostValue: #"reader" forKey: #"service"];
[request setPostValue: source forKey: #"source"];
[request setPostValue: continueUrl forKey: #"continue"];
[request setDelegate: self];
[request setDidFailSelector: #selector(loginRequestFailed:)];
[request setDidFinishSelector: #selector(loginRequestFinished:)];
[request start];
}
-(void)loginRequestFinished:(ASIHTTPRequest *)request
{
NSString *responseString = [request responseString];
//login failed
if ([responseString containsString: #"Error=BadAuthentication" ignoringCase: YES])
{
[self setLastError: [self errorWithDescription: #"Bad Username/Passsword" code: 0x001 andErrorLevel: 0x00]];
if ([delegate respondsToSelector: #selector(gReaderLoginDidFail:)])
{
[delegate gReaderLoginDidFail: self];
}
return NO;
}
//captcha required
if ([responseString containsString: #"CaptchaRequired" ignoringCase: YES])
{
[self setLastError: [self errorWithDescription: #"Captcha Required" code: 0x001 andErrorLevel: 0x00]];
if ([delegate respondsToSelector: #selector(gReaderLoginDidFail:)])
{
[delegate gReaderLoginDidFail: self];
}
return NO;
}
//extract SID + auth
NSArray *respArray = [responseString componentsSeparatedByCharactersInSet: [NSCharacterSet newlineCharacterSet]];
NSString *sidString = [respArray objectAtIndex: 0];
sidString = [sidString stringByReplacingOccurrencesOfString: #"SID=" withString: #""];
[self setSid: sidString];
NSString *authString = [respArray objectAtIndex: 2];
authString = [authString stringByReplacingOccurrencesOfString: #"Auth=" withString: #""];
[self setAuth: authString];
//mesage delegate of success
if ([delegate respondsToSelector: #selector(gReaderLoginDidSucceed:)])
{
[delegate gReaderLoginDidSucceed: self];
}
return YES;
}
- (void)loginRequestFailed:(ASIHTTPRequest *)request
{
NSError *error = [request error];
//NSLog(#"login request failed with error: %#", [error localizedDescription]);
[self setLastError: error];
if ([delegate respondsToSelector: #selector(gReaderLoginDidFail:)])
{
[delegate gReaderLoginDidFail: self];
}
}
After login you can use sid and auth to forge requests to the Reader's API endpoints.
Example:
- (ASIHTTPRequest *) requestForAPIEndpoint: (NSString *) apiEndpoint
{
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:[NSURL URLWithString: apiEndpoint]];
[request addRequestHeader: #"User-Agent" value: #"NetNewsWire/3.2b25 (Mac OS X; http://www.newsgator.com/Individuals/NetNewsWire/)"];
[request addRequestHeader: #"Cookie" value: [self sidHeader]];
[request addRequestHeader: #"Authorization" value: [self authHeader]];
return request;
}
An interesting read about Google Reader and its private API is http://timbroder.com/2007/08/google-reader-api-functions.html
Please make sure to read the latest comments :)
/edit: I updated the code to use the auth header (which google introduced in june this year). I guess this would be the place to put your OAuth token in if you would use OAuth. guess

Answer 2

Ive since found this: "The Google Data APIs Objective-C Client Library provides an iPhone static library, a Mac OS X framework, and source code that make it easy to access data through Google Data APIs. " code.google.com/p/gdata-objectivec-client - which is great!
It doesn't include the Reader API however (because it's not been released).
I have been able to access the API by changing (in the OAuthSampleTouch example)
NSString *scope = #"http://www.google.com/m8/feeds/";
in OAuthSampleRootViewControllerTouch.m to
NSString *scope = #"http://www.google.com/reader/api/*";
and
urlStr = #"http://www.google.com/m8/feeds/contacts/default/thin";
to
urlStr = #"http://www.google.com/reader/atom/user/-/label/Design";
where Design is a folder name - check this http://code.google.com/p/pyrfeed/wiki/GoogleReaderAPI its a great help.
Update
I have since found that this technique to be the best / lightest / less-complicated :
Native Google Reader iPhone Application