# Using the Graph API, iOS



Use the [Graph API](https://developers.facebook.com/docs/graph-api/quickstart) to get data in and out of Facebook's [social graph](https://developers.facebook.com/docs/opengraph).

This includes:

- Fetching profile information to provide social context.
- Fetching user information such as their likes or photos.
- Publish posts (including videos or photos) to Facebook.
- Publishing open graph stories to Facebook.
- For more features, see the [Graph API documentation](https://developers.facebook.com/docs/graph-api).

This guide describes how you work with the Graph API using the Facebook SDK for iOS.

## Prerequisites {#prerequisites}

Calling the Graph API requires someone to login to your app via Facebook and authorize permissions for your app.

For example, if you want to fetch someone's email address, your app must be authorized for the `email` permission. Be sure you are familiar with:

- [Login on iOS](https://developers.facebook.com/documentation/facebook-login/ios)
- [Managing Permissions on iOS](https://developers.facebook.com/documentation/facebook-login/ios/permissions)
- [Handling Errors](https://developers.facebook.com/documentation/ios/errors)

You also need your development environment set up for the iOS SDK and your app set up, see [iOS, Getting Started Guide](https://developers.facebook.com/documentation/ios/getting-started).

## Fetch User Data {#fetching}

The SDK has two classes to work with the Graph API: `FBSDKGraphRequest` and `FBSDKGraphRequestConnection` which are similar to the Foundation framework's `NSURLRequest` and `NSURLRequestConnection`.

To use the `FBSDKGraphRequest` you provide the request with a specific Graph API endpoint. Then call `FBSDKGraphRequestConnection` to start the request and process its completion.

For convenience, the SDK has a `startWithCompletionHandler:` method on `FBSDKGraphRequest` to implicitly create a `FBSDKGraphRequestConnection` for you.

For example to fetch the profile information for the person currently logged into your app, make this call:

```
guard AccessToken.current != nil else { return }

let request = GraphRequest(graphPath: "me", parameters: [:])
request.start() { connection, result, error in
    if let result = result, error == nil {
        print("fetched user: \(result)")
    }
}
```

## Batch Requests {#batching}

In Graph API you can make batch requests in a single HTTP request, see [Graph API, Making Batch Requests](https://developers.facebook.com/docs/graph-api/making-multiple-requests).

With the SDK, you can construct multiple requests and add them to the same `FBSDKGraphRequestConnection` instance. You should batch requests whenever possible to minimize network traffic.

For example here we request someone's Likes:

```
guard let token = AccessToken.current else { return }

if token.hasGranted("user_likes") {
    let meRequest = GraphRequest(graphPath: "me", parameters: [:])
    let likesRequest = GraphRequest(graphPath: "me/likes", parameters: [:])

    let connection = GraphRequestConnection()
    connection.add(meRequest) { connection, result, error in
        // Process the 'me' information
    }
    connection.add(likesRequest) { connection, result, error in
        // Process the 'likes' information
    }

    connection.start()
}
```

You can also specify batch parameters with the `addRequest:completionHandler:` overloads, which includes the ability to create a batch with dependent requests.

## Share Photos and Videos {#photos_and_videos}

While you can always manually create `FBSDKGraphRequests` to work with the Graph API endpoints, the Facebook SDK for iOS simplifies sharing photos and videos with `FBSDKShareKit.framework`. For example, to share a photo:

```
let image: UIImage!
let content = SharePhotoContent()
content.photos = SharePhoto(image: image, isUserGenerated: true)

// Assuming self implements SharingDelegate
let dialog = ShareDialog(
    viewController: self,
    content: content,
    delegate: self
)
dialog.show()
```

You can also share videos using the `FBSDKShareVideoContent` type.  See the [Sharing on iOS](https://developers.facebook.com/documentation/sharing/ios).

## Delete Objects {#deleting}

You can also delete objects that your app created by sending a `DELETE` request with the object's ID as the graph path.

For example, imagine you published a photo to a Page and received an ID of “1234”. The following code would delete the photo:

```
guard let token = AccessToken.current else { return }

if token.hasGranted("pages_manage_posts") {
    let request = GraphRequest(graphPath: "1234", parameters: [:], httpMethod: .delete)
    request.start { connection, result, error in
        if error == nil {
            print("Deleted photo")
        }
    }
}
```

## Debugging Tips {#debugging_tips}

You can experiment and test your requests with the [Graph API Explorer](https://developers.facebook.com/tools/explorer).

You can also enable Graph API debug mode, see [iOS SDK Troubleshooting, Graph API Debug Mode](https://developers.facebook.com/documentation/ios/troubleshooting#graphapidebugmode).