(Visual FoxPro) Twitter OAuth1 Authorization (3-legged)

Demonstrates 3-legged OAuth1 authorization for Twitter.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL lcConsumerKey
LOCAL lcConsumerSecret
LOCAL lcRequestTokenUrl
LOCAL lcAuthorizeUrl
LOCAL lcAccessTokenUrl
LOCAL lcCallbackUrl
LOCAL lnCallbackLocalPort
LOCAL loHttp
LOCAL lnSuccess
LOCAL loReq
LOCAL loResp
LOCAL loHashTab
LOCAL lcRequestToken
LOCAL lcRequestTokenSecret
LOCAL loSbUrlForBrowser
LOCAL lcUrl
LOCAL loListenSock
LOCAL lnBackLog
LOCAL lnMaxWaitMs
LOCAL loTask
LOCAL loSock
LOCAL lcStartLine
LOCAL lcRequestHeader
LOCAL loSbResponseHtml
LOCAL loSbResponse
LOCAL loSbStartLine
LOCAL lnNumReplacements
LOCAL lcAuthVerifier
LOCAL lcAccessToken
LOCAL lcAccessTokenSecret
LOCAL lcUserId
LOCAL lcScreenName
LOCAL loJson
LOCAL loFac

lcConsumerKey = "TWITTER_CONSUMER_KEY"
lcConsumerSecret = "TWITTER_CONSUMER_SECRET"

lcRequestTokenUrl = "https://api.twitter.com/oauth/request_token"
lcAuthorizeUrl = "https://api.twitter.com/oauth/authorize"
lcAccessTokenUrl = "https://api.twitter.com/oauth/access_token"

* The port number is picked at random. It's some unused port that won't likely conflict with anything else..
lcCallbackUrl = "http://localhost:3017/"
lnCallbackLocalPort = 3017

* The 1st step in 3-legged OAuth1.0a is to send a POST to the request token URL to obtain an OAuth Request Token
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Http')
loHttp = CreateObject('Chilkat.Http')

loHttp.OAuth1 = 1
loHttp.OAuthConsumerKey = lcConsumerKey
loHttp.OAuthConsumerSecret = lcConsumerSecret

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.HttpRequest')
loReq = CreateObject('Chilkat.HttpRequest')
loReq.AddParam("oauth_callback",lcCallbackUrl)

loResp = loHttp.PostUrlEncoded(lcRequestTokenUrl,loReq)
IF (loHttp.LastMethodSuccess <> 1) THEN
    ? loHttp.LastErrorText
    RELEASE loHttp
    RELEASE loReq
    CANCEL
ENDIF

* If successful, the resp.BodyStr contains something like this:  
* oauth_token=-Wa_KwAAAAAAxfEPAAABV8Qar4Q&oauth_token_secret=OfHY4tZBX2HK4f7yIw76WYdvnl99MVGB&oauth_callback_confirmed=true
? loResp.BodyStr

IF (loResp.StatusCode <> 200) THEN
    ? "Failed response status code: " + STR(loResp.StatusCode)
    RELEASE loResp
    RELEASE loHttp
    RELEASE loReq
    CANCEL
ENDIF

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Hashtable')
loHashTab = CreateObject('Chilkat.Hashtable')
loHashTab.AddQueryParams(loResp.BodyStr)

lcRequestToken = loHashTab.LookupStr("oauth_token")
lcRequestTokenSecret = loHashTab.LookupStr("oauth_token_secret")
loHttp.OAuthTokenSecret = lcRequestTokenSecret

RELEASE loResp

? "oauth_token = " + lcRequestToken
? "oauth_token_secret = " + lcRequestTokenSecret

* ---------------------------------------------------------------------------
* The next step is to form a URL to send to the authorizeUrl
* This is an HTTP GET that we load into a popup browser.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbUrlForBrowser = CreateObject('Chilkat.StringBuilder')
loSbUrlForBrowser.Append(lcAuthorizeUrl)
loSbUrlForBrowser.Append("?oauth_token=")
loSbUrlForBrowser.Append(lcRequestToken)
lcUrl = loSbUrlForBrowser.GetAsString()

* At this point, your application should load the URL in a browser.
* For example, 
* in C#: System.Diagnostics.Process.Start(url);
* in Java: Desktop.getDesktop().browse(new URI(url));
* in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
*              wsh.Run url
* in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
* in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
* The Microsoft account owner would interactively accept or deny the authorization request.

* Add the code to load the url in a web browser here...
* Add the code to load the url in a web browser here...
* Add the code to load the url in a web browser here...

* When the url is loaded into a browser, the response from Twitter will redirect back to localhost:3017
* We'll need to start a socket that is listening on port 3017 for the callback from the browser.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Socket')
loListenSock = CreateObject('Chilkat.Socket')

lnBackLog = 5
lnSuccess = loListenSock.BindAndListen(lnCallbackLocalPort,lnBackLog)
IF (lnSuccess <> 1) THEN
    ? loListenSock.LastErrorText
    RELEASE loHttp
    RELEASE loReq
    RELEASE loHashTab
    RELEASE loSbUrlForBrowser
    RELEASE loListenSock
    CANCEL
ENDIF

* Wait for the browser's connection in a background thread.
* (We'll send load the URL into the browser following this..)
* Wait a max of 60 seconds before giving up.
lnMaxWaitMs = 60000
loTask = loListenSock.AcceptNextConnectionAsync(lnMaxWaitMs)
loTask.Run()

* At this point, your application should load the URL in a browser.
* For example, 
* in C#: System.Diagnostics.Process.Start(url);
* in Java: Desktop.getDesktop().browse(new URI(url));
* in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
*              wsh.Run url
* in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
* in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
* The Twitter account owner would interactively accept or deny the authorization request.

* Add the code to load the url in a web browser here...
* Add the code to load the url in a web browser here...
* Add the code to load the url in a web browser here...
* System.Diagnostics.Process.Start(url);

* Wait for the listenSock's task to complete.
lnSuccess = loTask.Wait(lnMaxWaitMs)
IF (NOT lnSuccess OR (loTask.StatusInt <> 7) OR (loTask.TaskSuccess <> 1)) THEN
    IF (NOT lnSuccess) THEN
        * The task.LastErrorText applies to the Wait method call.
        ? loTask.LastErrorText
    ELSE
        * The ResultErrorText applies to the underlying task method call (i.e. the AcceptNextConnection)
        ? loTask.Status
        ? loTask.ResultErrorText
    ENDIF

    RELEASE loTask
    RELEASE loHttp
    RELEASE loReq
    RELEASE loHashTab
    RELEASE loSbUrlForBrowser
    RELEASE loListenSock
    CANCEL
ENDIF

* If we get to this point, the connection from the browser arrived and was accepted.

* We no longer need the listen socket...
* Stop listening on port 3017.
loListenSock.Close(10)

* First get the connected socket.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Socket')
loSock = CreateObject('Chilkat.Socket')
loSock.LoadTaskResult(loTask)
RELEASE loTask

* Read the start line of the request..
lcStartLine = loSock.ReceiveUntilMatch(CHR(13) + CHR(10))
IF (loSock.LastMethodSuccess <> 1) THEN
    ? loSock.LastErrorText
    RELEASE loHttp
    RELEASE loReq
    RELEASE loHashTab
    RELEASE loSbUrlForBrowser
    RELEASE loListenSock
    RELEASE loSock
    CANCEL
ENDIF

* Read the request header.
lcRequestHeader = loSock.ReceiveUntilMatch(CHR(13) + CHR(10) + CHR(13) + CHR(10))
IF (loSock.LastMethodSuccess <> 1) THEN
    ? loSock.LastErrorText
    RELEASE loHttp
    RELEASE loReq
    RELEASE loHashTab
    RELEASE loSbUrlForBrowser
    RELEASE loListenSock
    RELEASE loSock
    CANCEL
ENDIF

* The browser SHOULD be sending us a GET request, and therefore there is no body to the request.
* Once the request header is received, we have all of it.
* We can now send our HTTP response.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbResponseHtml = CreateObject('Chilkat.StringBuilder')
loSbResponseHtml.Append("<html><body><p>Chilkat thanks you!</b></body</html>")

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbResponse = CreateObject('Chilkat.StringBuilder')
loSbResponse.Append("HTTP/1.1 200 OK" + CHR(13) + CHR(10))
loSbResponse.Append("Content-Length: ")
loSbResponse.AppendInt(loSbResponseHtml.Length)
loSbResponse.Append(CHR(13) + CHR(10))
loSbResponse.Append("Content-Type: text/html" + CHR(13) + CHR(10))
loSbResponse.Append(CHR(13) + CHR(10))
loSbResponse.AppendSb(loSbResponseHtml)

loSock.SendString(loSbResponse.GetAsString())
loSock.Close(50)

* The information we need is in the startLine.
* For example, the startLine will look like this:
*  GET /?oauth_token=abcdRQAAZZAAxfBBAAABVabcd_k&oauth_verifier=9rdOq5abcdCe6cn8M3jabcdj3Eabcd HTTP/1.1
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbStartLine = CreateObject('Chilkat.StringBuilder')
loSbStartLine.Append(lcStartLine)
lnNumReplacements = loSbStartLine.Replace("GET /?","")
lnNumReplacements = loSbStartLine.Replace(" HTTP/1.1","")
loSbStartLine.Trim()

* oauth_token=abcdRQAAZZAAxfBBAAABVabcd_k&oauth_verifier=9rdOq5abcdCe6cn8M3jabcdj3Eabcd
? "startline: " + loSbStartLine.GetAsString()

loHashTab.Clear()
loHashTab.AddQueryParams(loSbStartLine.GetAsString())

lcRequestToken = loHashTab.LookupStr("oauth_token")
lcAuthVerifier = loHashTab.LookupStr("oauth_verifier")

* ------------------------------------------------------------------------------
* Finally , we must exchange the OAuth Request Token for an OAuth Access Token.

loHttp.OAuthToken = lcRequestToken
loHttp.OAuthVerifier = lcAuthVerifier

* We don't need the "Authorization: OAuth ..." header for this POST.
loHttp.OAuth1 = 0
loReq.RemoveParam("oauth_callback")
loReq.AddParam("oauth_verifier",lcAuthVerifier)
loReq.AddParam("oauth_token",lcRequestToken)

loResp = loHttp.PostUrlEncoded(lcAccessTokenUrl,loReq)
IF (loHttp.LastMethodSuccess <> 1) THEN
    ? loHttp.LastErrorText
    RELEASE loHttp
    RELEASE loReq
    RELEASE loHashTab
    RELEASE loSbUrlForBrowser
    RELEASE loListenSock
    RELEASE loSock
    RELEASE loSbResponseHtml
    RELEASE loSbResponse
    RELEASE loSbStartLine
    CANCEL
ENDIF

* Make sure a successful response was received.
IF (loResp.StatusCode <> 200) THEN
    ? loResp.StatusLine
    ? loResp.Header
    ? loResp.BodyStr
    RELEASE loHttp
    RELEASE loReq
    RELEASE loHashTab
    RELEASE loSbUrlForBrowser
    RELEASE loListenSock
    RELEASE loSock
    RELEASE loSbResponseHtml
    RELEASE loSbResponse
    RELEASE loSbStartLine
    CANCEL
ENDIF

* If successful, the resp.BodyStr contains something like this:
* oauth_token=85123455-fF41296Bi3daM8eCo9Y5vZabcdxXpRv864plYPOjr&oauth_token_secret=afiYJOgabcdSfGae7BDvJVVTwys8fUGpra5guZxbmFBZo&user_id=85612355&screen_name=chilkatsoft&x_auth_expires=0
? loResp.BodyStr

loHashTab.Clear()
loHashTab.AddQueryParams(loResp.BodyStr)

lcAccessToken = loHashTab.LookupStr("oauth_token")
lcAccessTokenSecret = loHashTab.LookupStr("oauth_token_secret")
lcUserId = loHashTab.LookupStr("user_id")
lcScreenName = loHashTab.LookupStr("screen_name")

RELEASE loResp

* The access token + secret is what should be saved and used for
* subsequent REST API calls.
? "Access Token = " + lcAccessToken
? "Access Token Secret = " + lcAccessTokenSecret
? "user_id = " + lcUserId
? "screen_name  = " + lcScreenName

* Save this access token for future calls.
* Just in case we need user_id and screen_name, save those also..
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')
loJson.AppendString("oauth_token",lcAccessToken)
loJson.AppendString("oauth_token_secret",lcAccessTokenSecret)
loJson.AppendString("user_id",lcUserId)
loJson.AppendString("screen_name",lcScreenName)

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.FileAccess')
loFac = CreateObject('Chilkat.FileAccess')
loFac.WriteEntireTextFile("qa_data/tokens/twitter.json",loJson.Emit(),"utf-8",0)

? "Success."

RELEASE loHttp
RELEASE loReq
RELEASE loHashTab
RELEASE loSbUrlForBrowser
RELEASE loListenSock
RELEASE loSock
RELEASE loSbResponseHtml
RELEASE loSbResponse
RELEASE loSbStartLine
RELEASE loJson
RELEASE loFac