Android Tutorial OAuth 2.0 / Google web services tutorial

Discussion in 'Tutorials & Examples' started by Erel, Jan 30, 2012.

  1. Erel

    Erel Administrator Staff Member Licensed User

    This tutorial is no longer relevant. Google doesn't allow using WebView to access the server response. Updated tutorial:

    OAuth is an authentication method which allows the user to grant your application access to private information in a controlled way.

    In order to access private information you need to get an access token.

    There are several steps required (the attached code takes care for most of the steps):
    - Register your application with Google. You will get "client id" and "client secret" values.


    In order to run this example you will need to first register a new application and fill ClientId and ClientSecret variables:

    - In your application you should show a WebView that handles the authentication.
    (the user default language is used in this dialog)
    The scope parameter should be set based on the required service.


    After the user approves the access the WebView is redirected to a different page. The authorization code appears in the page title. We extract it using WebViewExtender library. After extracting the code the WebView is removed.

    - Another Http call is required to get the access token.

    Once we have the access token we can send requests that access the user's private data.
    In the attached example we retrieve the user Gmail contacts list.

    OAuth 2.0 is a popular authentication method. It shouldn't be difficult to use this code with other web services such as Twitter, Facebook and others. It is much simpler than OAuth 1.0.
    The following libraries are required: HTTP, JSON (to parse the access token request) and WebViewXtended (to get the authorization code from the WebView title).
    The attached example also requires XmlSax for the contacts feed parsing.

    You will need to register a new application with Google in order to run the example. Once registered you should fill CliendId and ClientSecret variables.
    It takes two minutes to register a new application.

    Attached Files:

    Last edited: May 11, 2017
    DonManfred and GudEvil like this.
  2. thedesolatesoul

    thedesolatesoul Expert Licensed User

    Nice tutorial :)
    This will come handy with so many google services!
    gpapageor likes this.
  3. stevel05

    stevel05 Expert Licensed User

    Thanks Erel, I've just been banging my head against the wall looking at the Facebook API, it did occur to me that using HTTP may be a simpler solution and you have provided it.

    I'll have a look at Google first, then Facebook later.


  4. salvatore75

    salvatore75 Member Licensed User

    I'm going crazy for a http post to Google Fusion tables !!!!!!!!
    I modified the example gmailcontacts OAuth 2.0 / Google web services tutorial for accessing google fusion tables. I get the access_token but the on HttpUtils.PostByte i get in sub hc_ResponsError StatusCode = 400 & Reason = "parse error near access_token" !!!

    Erel Help me I'm crazy, I tried in a thousand ways!

    here the code:

    Dim su As StringUtils
    Dim bytes() As Byte
    Dim sdata As String
    Dim GoogleFusionPath As String
    Dim query, auth, tail As String

    query="INSERT INTO 842604 (Barcode, GPS, Data) VALUES ('22222222', '10.1 11.1', '28/01/2012')"

    auth="&access_token="& AccessToken
    tail = "&jsonCallback=?"

    sdata = "sql=" & su.EncodeUrl(query & auth & tail ,"UTF8")

    HttpUtils.PostBytes("INSERT",GoogleFusionPath,byte s)
  5. Erel

    Erel Administrator Staff Member Licensed User

  6. margret

    margret Well-Known Member Licensed User

    No Email or Website Data

    Hello, I have an issue I hope you can help with. I am using the OAuth 2.0 Tutorial Code Erel wrote. In the code listed below, it does not return any Emails or Websites, it return every thing else, Notes, Phone #'s, etc. I have logged on to Google with a PC and created a half dozen contacts with all the fields filled in. Now I run this code with just the message box to display the field names and values passed to XML_EndElement and all works but the email and websites. It does return as the Name of Field but the Text is always blank, even though they are populated in Google's contacts. All other fields return their respective data just as they should. Any Ideas?

    Sub XML_EndElement (Uri As String, Name As String, Text As StringBuilder)
    Msgbox(Text & CRLF & CRLF & Uri, Name)
    End Sub
    Last edited: Mar 29, 2012
  7. Erel

    Erel Administrator Staff Member Licensed User

    You should check the contacts API. I guess that not all of the data returns in this feed. You should probably send another request for each contact to get more information.
  8. margret

    margret Well-Known Member Licensed User

    @Erel, I really don't understand this stuff, but looking through the Google information, I found this:
    To retrieve all of a user's contacts, send an authorized GET request to the following URL:{userEmail}/full

    In your sample you used:

    I changed the above line to the feed with the [userEmail] in it and I get the same response. This is from the docs of Google Contacts API-3. Any other info you might can provide a blind horse?
  9. Erel

    Erel Administrator Staff Member Licensed User

  10. thedesolatesoul

    thedesolatesoul Expert Licensed User

    Hi margret,
    Try as Erel says for a single contact using:
    Get the contactid from the first request.
    Or even better try:
    Are you sure it does not return only the email addresses?
    Because there is a 'max-results' limit which means mostly the old contacts are returned and the new ones you added are not returned.
    Also, I had some problem due to contact groups. I think the 'My Contacts' group is not returned unless forced.
    The API is a bit temperamental, you might have to experiment.
  11. margret

    margret Well-Known Member Licensed User

    It does not return the email or the websites that were entered. The maxlimit is set to 100. This is not a problem as I just created this google email, so it's new. I then added six contacts and that's all there is. I get the notes, multiple phone #s, etc. I just get a blank/empty value for email addresses and website urls even though they are there. In the message box the header does come up and says, but the text is blank. The same is true for the website, it comes up in the header of the message box but the text is again blank. I will try it again getting a single contact with the id and see if it's any different.
    Last edited: Mar 30, 2012
  12. margret

    margret Well-Known Member Licensed User


    I went back and tried one contact at a time, I get the same results. This time I wrote the order of the data coming in. The msgbox() displays the name of all entries I am looking for it is just that the birthday, emails and websites return blank. The fields below are what's returned and they are returned in this order. You can see after it starts sending blanks, there are fields after that, that return the correct data:

    updated = correct data
    edited = correct data
    title = correct data
    content = correct data
    fullName = correct data
    givenName = correct data
    familyName = correct data
    name = correct data
    birthday = blank
    email = blank
    phoneNumber = correct data
    phoneNumber = correct data
    phoneNumber = correct data
    formattedAddress = correct data
    street = correct data
    postcode = correct data
    city = correct data
    region = correct data
    structuredPostalAddress = correct data
    website = blank
    website = blank
    website = blank
    website = blank
    This happens on all six contacts in the Google contacts. There are only six contacts total.
    Last edited: Mar 30, 2012
  13. intoxicatedp

    intoxicatedp New Member

    I have a question


    "" file does not download, what should I do?

    Please help me .. ㅠ ㅠ
  14. Erel

    Erel Administrator Staff Member Licensed User

    This file is only available to licensed users. If you have bought Basic4android then please contact
  15. keirS

    keirS Well-Known Member Licensed User

    Cant seem to get this to work. When I register my app Google doesn't give me a client secret. I have a client ID and it shows me the package name of the app and the SHA1 certificate fingerprint of the keystore file for the app which I got from running the the keytool program distributed with Java but it doesn't show me a client secret?

  16. Erel

    Erel Administrator Staff Member Licensed User

    Which Google service do you want to use? Have you enabled it in the console?
  17. keirS

    keirS Well-Known Member Licensed User

    I actually got the example working by creating a new client id and selecting application of type "other" which gives me a client secret. I would be useful to know how oAuth works with the application type "android" though. Couldn't find any examples of how this might work in the Google API documentation as the examples all appear to use client secret which you don't get when selecting android as the application type.
  18. sally3599

    sally3599 Member Licensed User

    where is the debug keystore located

    For B4A, where is the debug keystore located?
    keytool -exportcert -alias androiddebugkey -keystore path-to-debug-or-production-keystore -list -v
    Any help will be appreciate it.
  19. Erel

    Erel Administrator Staff Member Licensed User

    Is this question related to this thread?
  20. sally3599

    sally3599 Member Licensed User

    OAuth 2.0 for Installed Applications

    Yes, create a Client ID for Installed application on Android, it needs to run the Keytool command to generate the signing certificate's SHA-1 fingerprint first.

    I use the Client ID & Client Secret for Web application, it will show a error about Redirect URI.

    So what's the "path-to-debug-or-production-keystore" you using?

    keytool -exportcert -alias androiddebugkey -keystore path-to-debug-or-production-keystore -list -v
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