Converting a UIImage to jpeg/png file for sharing using AddThis Plug-in - objective-c

Question

I want to convert a UIImage into a format such as a jpeg or png so that I can then share that file using the IOS plug-in called "AddThis".
I tried to share it using just the UIImage but the plug-in doesn't support it so I need to find a way to convert the UIImage to a jpeg first, then add it into this code:
[AddThisSDK shareImage:[UIImage imageNamed:#"test.jpg] withService:#"twitter" title:#"I'm sharing something" description:#"Random description of image"];
the code has to have shareImage:[UIImageNamed:#""] otherwise an error occurs.
So far I've tried to convert it using UIImageJPEGRepresentation but I don't think I've done it properly. To be honest I tried to do it similarly to how you'd convert it straight from taking an image:
NSString *jpgPath = [NSHomeDirectory() stringByAppendingPathComponent:#"photo_boom.jpg"];
[UIImageJPEGRepresentation(shareImage, 1.0) writeToFile:jpgPath atomically:YES];
NSError *error;
NSFileManager *fileMgr = [NSFileManager defaultManager];
NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:#"photo_boom.jpg"];
NSLog(#"Documents directory: %#", [fileMgr contentsOfDirectoryAtPath:documentsDirectory error:&error]);
Something tells me this isn't the correct way... mainly because I haven't been able to get it to work.
I'd really appreciate any kind of help!
Basically, I've made a UIImage from converting a UIView:
UIGraphicsBeginImageContext(firstPage.bounds.size);
[firstPage.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
Which I then want to give a jpeg format because when I tried to simply put it in as
[AddThisSDK shareImage:image withService:#"twitter" title:#"I'm sharing something" description:#"Random description of image"];
It gives me an error

Answer 1

UIImage has its own internal representation of an image, so it's irrelevant whether you load it with jpeg or png data.
The API call you're interested has a UIImage as the first parameter, so something along the lines of
[AddThisSDK shareImage:[UIImage imageNamed:#"photo_boom.jpg"]
withService:#"twitter"
title:#"I'm sharing something"
description:#"Random description of image"];
should work, provided photo_boom.jpg is included in your bundle. If you're loading a previously saved image from a folder, you'll need something like this:
NSString *jpgPath = [NSHomeDirectory() stringByAppendingPathComponent:#"photo_boom.jpg"];
UIImage * myImage = [UIImage imageWithContentsOfFile: jpgPath];
[AddThisSDK shareImage:myImage
withService:#"twitter"
title:#"I'm sharing something"
description:#"Random description of image"];
If that doesn't work, have you tried putting a breakpoint on the AddThisSDK line, and checking the value of image? Type po image on the console.