(Perl) Refresh a Dynamics CRM OAuth2 Access Token

Demonstrates how to refresh an expiring Dynamics CRM access token using the refresh token. endpoint.

(If a REST API call fails with a 401 unauthorized error, an application can auto-recover by refreshing the access token, and then re-send the request using the new token.)

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

#  This example requires the Chilkat API to have been previously unlocked.
#  See Global Unlock Sample for sample code.

#  We previously obtained an access token and saved the JSON to a file using this example:
#  Get Dynamics CRM OAuth2 Access Token

#  This example will examine the JSON and expiration date, and if near expiration will
#  refresh the access token.

$json = chilkat::CkJsonObject->new();
$success = $json->LoadFile("qa_data/tokens/dynamicsCrm.json");
if ($success != 1) {
    exit;
}

#  The contents of the JSON look 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": "..."
#  }

#  The "expires_on" value is a Unix time.
$dtExpire = chilkat::CkDateTime->new();
$dtExpire->SetFromUnixTime(0,$json->IntOf("expires_on"));

#  If this date/time expires within 10 minutes of the current system time, refresh the token.

#  OK, we need to refresh the access token by sending a POST...
# 

$req = chilkat::CkHttpRequest->new();
$req->AddParam("grant_type","refresh_token");
$req->AddParam("redirect_uri","http://localhost:3017/");
$req->AddParam("client_id","DYNAMICS-CRM-CLIENT-ID");
$req->AddParam("client_secret","DYNAMICS-CRM-SECRET-KEY");
$req->AddParam("refresh_token",$json->stringOf("refresh_token"));
$req->AddParam("resource","https://mydynamicsdomain.api.crm.dynamics.com");

$http = chilkat::CkHttp->new();

# resp is a HttpResponse
$resp = $http->PostUrlEncoded("https://login.microsoftonline.com/DYNAMICS-ENDPOINT-GUID/oauth2/token",$req);
if ($http->get_LastMethodSuccess() != 1) {
    print $http->lastErrorText() . "\r\n";
    exit;
}

#  Load the JSON response.
$json->Load($resp->bodyStr());
$json->put_EmitCompact(0);

#  Show the JSON response.
print $json->emit() . "\r\n";

print "Response status code: " . $resp->get_StatusCode() . "\r\n";

#  If the response status code is not 200, then it's an error.
if ($resp->get_StatusCode() != 200) {
    exit;
}

#  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") != 1) {
    $dtExpire->SetFromCurrentSystemTime();
    $dtExpire->AddSeconds($json->IntOf("expires_in"));
    $json->AppendString("expires_on",$dtExpire->getAsUnixTimeStr(0));
}

#  Save the refreshed access token JSON to a file for future requests.
$fac = chilkat::CkFileAccess->new();
$fac->WriteEntireTextFile("qa_data/tokens/dynamicsCrm.json",$json->emit(),"utf-8",0);