Using Facebook API for Android (Windows starters guide)

Here Ive used the instructions from Facebook itself, but added some extra info where its really not clear for windows users.

Before you begin development with the Facebook Android SDK, you will need to install the Android SDK and dev tools, Git (the source control client we use for this SDK) and then clone the lastest version of the SDK from GitHub:

Install Android SDK & the Eclipse Plugin
Install Git
Clone the GitHub repository: git clone git://github.com/facebook/facebook-android-sdk.git

"Clone the GitHub repository" means load up "GitBash" and type "git clone git://github.com/facebook/facebook-android-sdk.git", after some downloading the files you want will appear in: C:\Users\user\YourUserName - personally Id copy them somewhere more memorable and not have them lying around randomly in this directory (this whole "git" thing is a bit weird to me feels archaic and linuxy ;))

Once you have everything installed, open Eclipse and create a new Android Project (File | New | Project ...). We will use this project for the Facebook Android SDK source and then reference it from our app. As such, we need to get the content by selecting Create project from existing source and specifying the facebook directory from your git repository (~/facebook-android-sdk/facebook). (OR the sensible place we copied them too earlier :-))

With the SDK project created, we can create the app. Create a new Android Project (the Facebook SDK project will stay open in the Eclipse Workspace) from File | New | Project..., using the defaults and populating the require fields.

Once your app project is created, you will need to add a reference to the Facebook SDK project. You do this by opening the properties window for our app (File | Properties), selecting the Android item from the list, pressing the Add... button in the Library area and selecting the Facebook SDK project created above.

Once the Facebook SDK is referenced, the app manifest needs to be modified to allow the app to make network calls to Facebook. This is accomplished by adding the following to the AndroidManifest.xml file in the app project:

We now need to export the signature for your app so that Facebook can use to ensure users are only communicating with your app on the Android. This is done by running the keytool. The following shows how to export the key for your app using the debug defaults specified by the Android SDK and Eclipse:

keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore
| openssl sha1 -binary
| openssl base64

NOTE: this command is from facebook docs, it didnt work for me (or at least the path was confusing and those weird extra commands seperated by a pipe, it doesnt explain to have them all on one line etc), try something along the lines of:

keytool -exportcert -alias androiddebugkey -keystore C:\Users\user\.android\debug.keystore | openssl sha1 -binary | openssl base64

when it asks for a password enter "android", hopefully you will see something like this:

Enter keystore password: android
YKnCrNlSSeZLITpr/GKiENUJItM=

if so, cheer and smile for a bit.

This tool generates a string that must be registered in the Mobile & Devices section of the Developer App for your app:

You have to edit it then click "mobile" and look for "Android Key Hash" and past in the stringfrom the command line where you ran keystore.

Installing the Facebook Android App

To help with debugging your app in the Android emulator, we provide a binary image of the Facebook Android that you can install with the adb tool in the Android SDK.

adb install ~/facebook-android-sdk/Facebook.apk
Your app will still work without installing this image, but we will default to using Platform Dialogs for sign-in rather than using the Facebook App requiring you to sign-in every time you run your app in the emulator.

Single-Sign-On (SSO)

As with the iOS SDK, one of the most compelling features of the Android SDK is Single-Sign-On (SSO). SSO lets users sign into your app using their Facebook identity. If they are already signed into the Facebook Android app on their device they do not have to even type a username and password. Further, because they are signing to your app with their Facebook identity, you will have access to their profile information and social graph.

Adding SSO to your app is very simple with the Facebook SDK. The below example outlines what code must be written to enable this feature. For the sake of simplicity, SSO functionality will be added to the Activity that was created by Eclipse when the app project was created:

(ps - edit your app id where it says Facebook facebook = new Facebook("YOUR_APP_ID"); - app id is in the mobile bit of your facebook developer page where the android hash was)

package com.greatap;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import com.facebook.android.*;
import com.facebook.android.Facebook.*;

public class MyGreatActivity extends Activity {

Facebook facebook = new Facebook("YOUR_APP_ID");

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

facebook.authorize(this, new DialogListener() {
@Override
public void onComplete(Bundle values) {}

@Override
public void onFacebookError(FacebookError error) {}

@Override
public void onError(DialogError e) {}

@Override
public void onCancel() {}
});
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);

facebook.authorizeCallback(requestCode, resultCode, data);
}
}

When the above Activity is built and run as part of your app, you will prompted with the user authorization dialog:

This dialog allows the user to grant your app permission to access their information. If the user presses Allow, your app is authorized and you will have access to the user's profile and social graph through the facebook instance. If the user presses Don't Allow, your app is not authorized and you will not have access to the user's data.

By default, the user is asked to authorize the app to access basic information that is available publicly or by default on Facebook. If your app needs more than this basic information to function, you must request specific permissions from the user. This is accomplished by passing String[] of permissions to the authorize method. The following example shows how to ask for access to user's email address and their news feed:

facebook.authorize(this, new String[] { "email", "read_stream" },

new DialogListener() {
@Override
public void onComplete(Bundle values) {}

@Override
public void onFacebookError(FacebookError error) {}

@Override
public void onError(DialogError e) {}

@Override
public void onCancel() {}
}
);

A full list of permissions is available in our permissions reference. There is a strong inverse correlation between the number of permissions your app requests and the number of users that will allow those permissions. The greater the number of permissions you ask for, the lower the number of users that will grant them; so we recommend that you only request the permissions you absolutely need for your app.

Calling the Graph API

The Android SDK provides a straightforward set of methods to access the Graph API and the Legacy REST API:

// get information about the currently logged in user
facebook.request("me");
//get the logged-in user's friends
facebook.request("me/friends");

//call a Legacy REST API method
Bundle parameters = new Bundle();
parameters.putString("method", "auth.expireSession");
String response = request(parameters);
These methods are called synchronously and will block the UI, so we recommend that calling this in a separate thread and then marshal the results back to the UI thread. The Facebook SDK provides a class, AsyncFacebookRunner, that you can utilize for this purpose.

Displaying Platform Dialogs

The Android SDK provides the dialog method to display Platform Dialogs within the context of your app. Simply pass in the name of the dialog to display along with a delegate to handle the result. The following example displays the Feed Dialog:

facebook.dialog(this,"feed",

new DialogListener() {
@Override
public void onComplete(Bundle values) {}

@Override
public void onFacebookError(FacebookError error) {}

@Override
public void onError(DialogError e) {}

@Override
public void onCancel() {}
}
);

That was a basic intro, the developer docs dont mention anything about say posting on someones wall, so coming up soon I will add to the forum how to post to someone's wall on facebook - have a search on the forum to find it..

gaz.