Facebook Contacts

Jon Schuster — Sat, 29 Dec 2007 02:35:04 GMT

	By using the Facebook Developer Toolkit and the Bluetooth and Contacts APIs from the Coding4Fun Developer Toolkit, I created an application which transfers information about your Facebook friends to your mobile phone.
Jon Schuster Clarity Consulting Difficulty: Intermediate Time Required: 6-10 hours Cost: Free Software: Visual Basic or Visual C# Express Editions, Microsoft Windows Vista, Coding4Fun Developer Toolkit, Facebook Developer Toolkit Hardware: Bluetooth-enabled computer and phone Download: Download

Facebook is a great social networking site which keeps track of all kinds of information about your friends. Since things like your friends’ hometown, picture, and even the correct spelling of their name are already provided for you there, it would be great if you could automatically send all of that information to your phone, instead of having to manually type it in yourself. By using a couple of different toolkits, I was able to create a simple application which does all of this for me without writing a lot of code.

Disclaimer: Unfortunately, the Facebook API does not allow you to get a user’s contact information, such as phone number or e-mail address. If it did, they would certainly be included here, but as it is I’m limited to the information that Facebook provides.

To give a quick overview, the sample first uses the Facebook Developer Toolkit to connect to Facebook and download information about the user’s friends. These are displayed in a list on the main form, and multiple users can be selected with checkboxes. Then, using the Bluetooth API from the Coding4Fun Developer Toolkit, I get a list of Bluetooth devices (including mobile phones) within range, allowing the user to select one of them. Finally, when the user clicks “OK”, I use the Contacts API, also from the Coding4Fun toolkit, to turn each of the selected users into a transferable file, and then send it to the phone over a Bluetooth connection. The following sections describe this process in more detail.

Figure 1: The Facebook Contacts main screen

Retrieving Information From Facebook

To get started developing applications with the Facebook API, you first need to register your application and get an API key from Facebook which will allow you to connect to their site and download data. Their Get Started page will lead you through the process.

Now that you have an API key, you can start developing. While you can connect to Facebook and get the information manually through HTTP REST calls, I chose to use the Facebook Developer Toolkit, which took care of maintaining a connection, requesting the information, and parsing the response into objects that I can use in code. The following code loads the user’s friends into memory, using the included FacebookService component:

private void LoadFriends()
{
    List<User> users = new List<User>();

    try
    {
        users = new List<User>(facebookService1.GetFriends());
    }
    catch (FacebookInvalidUserException)
    {
        this.Close();
        return;
    }
    catch (FacebookException)
    {
        // do nothing: this exception just means no friends were returned,
        // so we can leave the users list empty
    }

    users.Sort(Compare);
    _friends = users;
}

VB.NET

Private Sub LoadFriends()
    Dim users As List(Of User) = New List(Of User)()

    Try
        users = New List(Of User)(facebookService1.GetFriends())
    Catch e1 As FacebookInvalidUserException
        Me.Close()
        Return
    Catch e2 As FacebookException
        ' do nothing: this exception just means no friends were returned,
        ' so we can leave the users list empty
    End Try

    users.Sort(AddressOf Compare)
    _friends = users
End Sub

I sort the users by comparing their last names, and then their first names if the last names are equal:

private int Compare(User leftUser, User rightUser)
{
    int lastNameComparison = leftUser.LastName.CompareTo(rightUser.LastName);

    if (lastNameComparison != 0)
    {
        return lastNameComparison;
    }

    return leftUser.FirstName.CompareTo(rightUser.FirstName);
}

VB.NET

Private Function Compare(ByVal leftUser As User, ByVal rightUser As User) As Integer
    Dim lastNameComparison As Integer = leftUser.LastName.CompareTo(rightUser.LastName)

    If lastNameComparison <> 0 Then
        Return lastNameComparison
    End If

    Return leftUser.FirstName.CompareTo(rightUser.FirstName)
End Function

On Facebook, most users are a part of one or more “networks”, such as “Chicago, IL”, or “Notre Dame”. For my application, I wanted to be able to filter the displayed friends according to their associated networks. To do this, I first had to get a list of networks from all my Facebook friends:

private List<string> GetNetworks()
{
    List<string> networkNames = new List<string>();

    foreach (User friend in _friends)
    {
        foreach (Network network in friend.Affiliations)
        {
            if (!networkNames.Contains(network.Name))
            {
                networkNames.Add(network.Name);
            }
        }
    }

    networkNames.Sort();
    networkNames.Insert(0, ALL_NETWORKS);

    return networkNames;
}

VB.NET

Private Function GetNetworks() As List(Of String)
    Dim networkNames As List(Of String) = New List(Of String)()

    For Each [friend] As User In _friends
        For Each network As Network In [friend].Affiliations
            If (Not networkNames.Contains(network.Name)) Then
                networkNames.Add(network.Name)
            End If
        Next network
    Next [friend]

    networkNames.Sort()
    networkNames.Insert(0, ALL_NETWORKS)

    Return networkNames
End Function

This list was displayed as a combo box on my form. Then, whenever the selection in the combo box changed, I had to filter the displayed list:

private void FilterDisplayedFriends(string selectedNetwork)
{
    List<User> friendsToDisplay;

    if (selectedNetwork.Equals(ALL_NETWORKS))
    {
        friendsToDisplay = _friends;
    }
    else
    {
        friendsToDisplay = new List<User>();

        foreach (User friend in _friends)
        {
            foreach (Network network in friend.Affiliations)
            {
                if (network.Name.Equals(selectedNetwork))
                {
                    friendsToDisplay.Add(friend);
                    continue;
                }
            }
        }
    }

    Display(friendsToDisplay);
}

VB.NET

Private Sub FilterDisplayedFriends(ByVal selectedNetwork As String)
    Dim friendsToDisplay As List(Of User)

    If selectedNetwork.Equals(ALL_NETWORKS) Then
        friendsToDisplay = _friends
    Else
        friendsToDisplay = New List(Of User)()

        For Each [friend] As User In _friends
            For Each network As Network In [friend].Affiliations
                If network.Name.Equals(selectedNetwork) Then
                    friendsToDisplay.Add([friend])
                    Continue For
                End If
            Next network
        Next [friend]
    End If

    Display(friendsToDisplay)
End Sub

Connecting to the Phone via Bluetooth

Now we have a list of friends that we can search through and select from. The next step is to transform the users we are going to send to the phone into vCard files. vCards are a common, human-readable file format for exchanging contact information between computers or other devices. Fortunately, the Contacts API released with the Coding4Fun Toolkit can create vCards for me. All I have to do is provide the mapping from the properties of a Facebook User object to those of a Contact object (using the included SimpleContactView).

private void FillContact(Contact contact, User facebookUser, WebClient webClient)
{
    SimpleContactView simpleContact = new SimpleContactView(contact);
    simpleContact.FirstName = facebookUser.FirstName;
    simpleContact.LastName = facebookUser.LastName;
    Location location = facebookUser.CurrentLocation;

    if (location != null)
    {
        simpleContact.HomeCity = location.City;

        if (location.StateAbbreviation != Facebook.Entity.StateAbbreviation.Unknown)
        {
            simpleContact.HomeState = location.StateAbbreviation.ToString();
        }

        if (location.Country != Facebook.Entity.Country.Unknown)
        {
            simpleContact.HomeCountry = ToString(location.Country);
        }

        simpleContact.HomeZip = location.ZipCode;
    }

    if (facebookUser.Sex == Facebook.Entity.Gender.Female)
    {
        simpleContact.Gender = Contacts.Gender.Female;
    }
    else if (facebookUser.Sex == Facebook.Entity.Gender.Male)
    {
        simpleContact.Gender = Contacts.Gender.Male;
    }
    else
    {
        simpleContact.Gender = Contacts.Gender.Unspecified;
    }

    if (!facebookUser.PictureUrl.Equals(DEFAULT_FACEBOOK_PICTURE))
    {
        string pictureFile = Path.GetTempFileName();
        webClient.DownloadFile(facebookUser.PictureUrl, pictureFile);

        using (FileStream fs = new FileStream(pictureFile, FileMode.Open))
        {
            contact.Photos[PhotoLabels.UserTile] = new Contacts.Photo(fs, "image");
        }

        File.Delete(pictureFile);
    }
}

VB.NET

Private Sub FillContact(ByVal contact As Contact, ByVal facebookUser As User, ByVal webClient As WebClient)
    Dim simpleContact As SimpleContactView = New SimpleContactView(contact)
    simpleContact.FirstName = facebookUser.FirstName
    simpleContact.LastName = facebookUser.LastName
    Dim location As Location = facebookUser.CurrentLocation

    If Not location Is Nothing Then
        simpleContact.HomeCity = location.City

        If location.StateAbbreviation <> Facebook.Entity.StateAbbreviation.Unknown Then
            simpleContact.HomeState = location.StateAbbreviation.ToString()
        End If

        If location.Country <> Facebook.Entity.Country.Unknown Then
            simpleContact.HomeCountry = ToString(location.Country)
        End If

        simpleContact.HomeZip = location.ZipCode
    End If

    If facebookUser.Sex = Facebook.Entity.Gender.Female Then
        simpleContact.Gender = Contacts.Gender.Female
    ElseIf facebookUser.Sex = Facebook.Entity.Gender.Male Then
        simpleContact.Gender = Contacts.Gender.Male
    Else
        simpleContact.Gender = Contacts.Gender.Unspecified
    End If

    If (Not facebookUser.PictureUrl.Equals(DEFAULT_FACEBOOK_PICTURE)) Then
        Dim pictureFile As String = Path.GetTempFileName()
        webClient.DownloadFile(facebookUser.PictureUrl, pictureFile)

        Using fs As FileStream = New FileStream(pictureFile, FileMode.Open)
            contact.Photos(PhotoLabels.UserTile) = New Contacts.Photo(fs, "image")
        End Using

        File.Delete(pictureFile)
    End If
End Sub

Finally, now that we can create vCards for Facebook users, we can make one for each selected user and send them off to the phone. First, however, we need to learn a little bit about how Bluetooth works. Every Bluetooth device implements a set of “profiles”, which are interface specifications that let Bluetooth devices know how to communicate with each other. Each profile is responsible for providing a different kind of service, such as phone headset communication, video streaming, and file transfer. To communicate with another Bluetooth device, you have to first find out if the device supports the profile you wish to use, connect to the device using that profile, and use the interface defined by the profile to accomplish your tasks.

For this application, I used the Object Push Profile (known as OBEX Object Push in the API), which is specifically designed to transfer objects such as vCards from one phone to another. The OppMananger component in the API takes care of the more difficult parts of making the connection. Once I’m connected, I just create a vCard for each user, transfer each one, and disconnect when I’m done:

private void SendToPhone(IEnumerable<User> users)
{
    Device device = (Device) cmbDevices.SelectedItem;
    RemoteService pushService;

    try
    {
       pushService = deviceServicesManager1.DiscoverServicesByType(device, ServiceType.OBEXObjectPush).ElementAt(0);
    }
    catch
    {
        MessageBox.Show("Could not connect to Bluetooth device " + cmbDevices.Text + ". It may be out of range.");
        return;
    }

    try
    {
        oppManager1.NetworkStream = pushService.Connect();
    }
    catch (ServiceConnectionException)
    {
        MessageBox.Show("Could not connect to Bluetooth device " + device.Name);
        return;
    }

    oppManager1.Connect();
    WebClient webClient = new WebClient();

    foreach (User user in users)
    {
        Contact contact = CreateContact(user, webClient);
        string tempFile = Path.GetTempFileName();
        string tempVCard = Path.GetDirectoryName(tempFile) + "\\" + Path.GetFileNameWithoutExtension(tempFile) + ".vcf";
        File.Delete(tempFile);
        contactsService1.SaveContactToVCard(contact, tempVCard);
        oppManager1.PushObject(tempVCard);
        File.Delete(tempVCard);
    }

    oppManager1.Disconnect();
    pushService.Disconnect();
    MessageBox.Show("Successfully transferred " + users.Count() + " friends to " + device.Name + ".");
}

VB.NET

Private Sub SendToPhone(ByVal users As IEnumerable(Of User))
    Dim device As Device = CType(cmbDevices.SelectedItem, Device)
    Dim pushService As RemoteService

    Try
        pushService = deviceServicesManager1.DiscoverServicesByType(device, ServiceType.OBEXObjectPush).ElementAt(0)
    Catch
        MessageBox.Show("Could not connect to Bluetooth device " & cmbDevices.Text & ". It may be out of range.")
        Return
    End Try

    Try
        oppManager1.NetworkStream = pushService.Connect()
    Catch e1 As ServiceConnectionException
        MessageBox.Show("Could not connect to Bluetooth device " & device.Name)
        Return
    End Try

    oppManager1.Connect()
    Dim webClient As WebClient = New WebClient()

    For Each user As User In users
        Dim contact As Contact = CreateContact(user, webClient)
        Dim tempFile As String = Path.GetTempFileName()
        Dim tempVCard As String = Path.GetDirectoryName(tempFile) & "\" & Path.GetFileNameWithoutExtension(tempFile) & ".vcf"
        File.Delete(tempFile)
        contactsService1.SaveContactToVCard(contact, tempVCard)
        oppManager1.PushObject(tempVCard)
        File.Delete(tempVCard)
    Next user

    oppManager1.Disconnect()
    pushService.Disconnect()
    MessageBox.Show("Successfully transferred " & users.Count() & " friends to " & device.Name & ".")
End Sub

Voila! You can now see your Facebook friends, including their profile pictures, on your phone. This application can also save Facebook friends as Windows Contacts. The code is mostly identical, except that the contacts get saved directly to the local machine using the ContactsService component, instead of using Bluetooth to connect to a separate device.

Conclusion

The three APIs I used for this project (Facebook, Bluetooth, and Contacts) made the application a breeze to set up. With the exception of one or two bits of code that could be improved, the APIs were all very simple and easy to use, and took care of all the low-level details so that I could focus on the code relevant to this project. There’s still more work that could be done, including more ways to search through Facebook friends besides the network and improving load time. Overall, though, I’m very pleased with how it came out, and I hope this has shown you how you can take advantage of some of these APIs to create a really useful tool.

About the Author

Jon Schuster is a consultant at Clarity Consulting, and can be reached at his e-mail address, jschuster [at] claritycon [dot] com

Channel 9

Facebook Contacts

Retrieving Information From Facebook

Connecting to the Phone via Bluetooth

Conclusion

About the Author