Doesn't a Named Credential handle OAuth2?

Question

Reading this doc from Salesforce, it was my understanding that a named credential handled authenticating when using it to make a callout. I'm going to go out on a limb and say that it probably does, I'm just doing something wrong. I set up a named credential for Quickbooks.

In order to create that Named Credential, I had to setup an Auth. Provider.

But then when I wrote this quick snippet of code,

public Integer getClientOutstandingBalance(Id persCustId) {
    String entId = [SELECT QB_Entity_Id__c FROM Account WHERE Id =: persCustId].QB_Entity_Id__c;

    if ( String.isEmpty(entId) ) return 0;

    String namedCredential = 'callout:Quickbooks';
    String custPath = '/v3/company/[redacted]/customer/4319';

    Http h = new Http();
    HttpRequest req = new HttpRequest();
    req.setEndpoint(namedCredential+custPath);
    req.setMethod( 'GET' );

    HttpResponse resp = h.send(req);

    System.debug('#### resp status: '+resp.getStatus());
    System.debug('#### resp code: '+resp.getStatusCode());
    System.debug('#### resp: '+resp.getBody());

    return 0;
}

The response I get from Quickbooks is,

#### resp status: Unauthorized

#### resp code: 401

#### resp: <?xml version="1.0" encoding="UTF-8" standalone="yes"?><IntuitResponse xmlns="http://schema.intuit.com/finance/v3" time="2018-10-03T11:23:32.531-07:00"><Fault type="AuthenticationFault"><Error code="100"><Message>General Authentication Error</Message><Detail>AuthenticationErrorGeneral: SRV-110-Authentication Failure , statusCode: 401</Detail></Error></Fault></IntuitResponse>

Is there something that I'm missing?

Answer 1

You will likely need to set an additional HTTP header with the OAuthToken . See Merge Fields for Apex Callouts That Use Named Credentials

Something like:

req.setHeader('Authorization', 'Bearer {!$Quickbooks.OAuthToken}'); 

Also, I see the named credential has an "Authentication Status" of "Pending".

Try completing the OAuth process first. Usually you check "Start Authentication Flow on Save" when editing the Named Credential.