Ruby Requires Chilkat v10.1.2+

HMRC OAuth2 Access Token

See more OAuth2 Examples

Demonstrates how to get an HMRC OAuth2 access token from a desktop (installed) application or script. This example gets an HMRC MTD VAT read/write access token. Ruby

require 'chilkat'

success = false

#  To further clarify, see OAuth 2.0 Authorization Flow

oauth2 = Chilkat::CkOAuth2.new()

#  This should be the port in the localhost callback URL for your app.
#  Important: Make sure the callback URI in your HMRC developer app 
#  is exactly "http://localhost:3017/".  Don't forget the ending "/" char.
#  The callback URL would look like "http://localhost:3017/" if the port number is 3017.

#  IMPORTANT: Don't forget to setup your HMRC application to use the Redirect URI "http://localhost:3017/" as shown
#  here: Configure Redirect URI for HMRC application
oauth2.put_ListenPort(3017)

oauth2.put_AuthorizationEndpoint("https://test-api.service.hmrc.gov.uk/oauth/authorize")
oauth2.put_TokenEndpoint("https://test-api.service.hmrc.gov.uk/oauth/token")

#  Replace with your actual client ID
oauth2.put_ClientId("HMRC-CLIENT-ID")

#  The scopes are documented in the HMRC reference documentation for each API.
#  This example gets a read/write access token for the HMRC MTD VAT API.
oauth2.put_Scope("read:vat write:vat")

#  Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
url = oauth2.startAuth()
if (oauth2.get_LastMethodSuccess() != true)
    print oauth2.lastErrorText() + "\n";
    exit
end

#  Launch the default browser on the system and navigate to the url.
#  The LaunchBrowser method was added in Chilkat v10.1.2.
success = oauth2.LaunchBrowser(url)
if (success == false)
    print oauth2.lastErrorText() + "\n";
    exit
end

#  Wait for the user to approve or deny authorization in the browser.
numMsWaited = 0
while (numMsWaited < 90000) and (oauth2.get_AuthFlowState() < 3)
    oauth2.SleepMs(100)
    numMsWaited = numMsWaited + 100
end

#  If the browser does not respond within the specified time, AuthFlowState will be:
#  
#  1: Waiting for Redirect – The OAuth2 background thread is waiting for the browser's redirect request.
#  2: Waiting for Final Response – The thread is awaiting the final access token response.
#  In either case, cancel the background task initiated by StartAuth.

if (oauth2.get_AuthFlowState() < 3)
    oauth2.Cancel()
    print "No response from the browser!" + "\n";
    exit
end

#  Check AuthFlowState to determine if authorization was granted, denied, or failed:
#  
#  3: Success – OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
#  4: Access Denied – OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
#  5: Failure – OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

if (oauth2.get_AuthFlowState() == 5)
    print "OAuth2 failed to complete." + "\n";
    print oauth2.failureInfo() + "\n";
    exit
end

if (oauth2.get_AuthFlowState() == 4)
    print "OAuth2 authorization was denied." + "\n";
    print oauth2.accessTokenResponse() + "\n";
    exit
end

if (oauth2.get_AuthFlowState() != 3)
    print "Unexpected AuthFlowState:" + oauth2.get_AuthFlowState().to_s() + "\n";
    exit
end

print "OAuth2 authorization granted!" + "\n";
print "Access Token = " + oauth2.accessToken() + "\n";

#  Get the full JSON response:
json = Chilkat::CkJsonObject.new()
json.Load(oauth2.accessTokenResponse())
json.put_EmitCompact(false)
print json.emit() + "\n";

#  The JSON response looks like this:

#  {
#    "token_type": "Bearer",
#    "scope": "user_impersonation",
#    "expires_in": "3599",
#    "ext_expires_in": "0",
#    "expires_on": "1524783438",
#    "not_before": "1524779538",
#    "resource": "https://mydomain.api.crm.dynamics.com",
#    "access_token": "...",
#    "refresh_token": "...",
#    "id_token": "..."
#  }

#  If an "expires_on" member does not exist, then add the JSON member by
#  getting the current system date/time and adding the "expires_in" seconds.
#  This way we'll know when the token expires.
if (json.HasMember("expires_on") != true)
    dtExpire = Chilkat::CkDateTime.new()
    dtExpire.SetFromCurrentSystemTime()
    dtExpire.AddSeconds(json.IntOf("expires_in"))
    json.AppendString("expires_on",dtExpire.getAsUnixTimeStr(false))
end

print json.emit() + "\n";

#  Save the JSON to a file for future requests.
fac = Chilkat::CkFileAccess.new()
fac.WriteEntireTextFile("qa_data/tokens/hmrc.json",json.emit(),"utf-8",false)