[TEMPLATE] Consuming Rest API in Apex (Zendesk)

ZendeskService.cls

// API we will consume 
// https://developer.zendesk.com/rest_api/docs/support/users

// Create a named credential "Zendesk" with the following value "https://company.zendesk.com/api/v2"
// Substitute in your company and the correct version number

public class ZendeskService {

  // create static variable for the endpoint we are going to leverage
  private static String CUSTOMER_RESOURCE = '/users/create_or_update.json';
  
  // create a lightweight wrapper class to hold the details we care about from the API response
  // class to hold callout response for parsing 
  private class Response {
    public Integer code {get;set;}
    public String body {get;set;}
    public Boolean success {get;set;}
    public String errorText {get;set;} // supply to caller if error
    public String createdZendeskCustomerId {get;set;}

    public Response(Integer code, String body) {
        this.code = code;
        this.body = body;
        this.success = code >= 200 && code < 300; //all 200 codes are considered success
        // customize this section futher based on each API resource
    }
  }
  
  // Methods to perform callouts
  private static Response ZendeskCallout() {
      // setup response to api requester 
      Response resp;
      String method = 'POST';

      // check to ensure a callout can be performed
      if(Limits.getCallouts() >= Limits.getLimitCallouts()) {
          resp.errorText = 'Maximum number of callouts has been reached.';
      } // configure and perform the callout
      else {
          // define basic callout variables
          HttpRequest req = new HttpRequest();
          HttpResponse res = new HttpResponse();
          Http h = new Http();

          // Configure the request  
          // setup request string
          req.setBody(request);
          // reference named credential plus static string endpoint value                                      
          req.setEndpoint('callout:Zendesk' + CUSTOMER_RESOURCE);
          req.setMethod(method); 
          req.setTimeout(120000); // max callout for APEX is 2 minutes
          // Configure standard headers (check each API's documentation for header specifics)
          req.setHeader('Accept', '*/*');
          req.setHeader('Content-Type', 'application/json'); // varies on each API (i.e. 'text/xml' :])
          req.setHeader('Connection', 'keep-alive');

          // Attempt the callout - create log on exception (common: send can fail, deserialization can fail)
          try {
              // Perform callout and set response
              res = h.send(req);
              system.debug(res);
              system.debug(res.getBody());
              resp = new Response(res.getStatusCode(), res.getBody());

              // check response
              if(resp.success) {
                  // deserialize the response into the inner class
                  Map<String, Object> results = (Map<String, Object>) JSON.deserializeUntyped(res.getBody());
                  resp.createdZendeskCustomerId = handleResponseCustomerId(results);
              }  else { 
                  // callout failed
                  resp.errorText = 'Callout failed. Failed to create Zendesk customers.' + res.getError();
              }
          } catch(Exception ex) {
              resp.errorText = 'An exception has een encountered while callout out to Integration: ' + ex.getMessage();
          }
      }

      // return the response
      return resp;
  }
  // parse method to extract user data of the JSON returned                                                         
  private static String handleResponseCustomerId(Map<String, Object> results) {
    String returnCustomerId;
    Map<String, Object> user = (Map<String, Object>) results.get('user');

    returnCustomerId = String.valueOf((Long)user.get('id'));
    return returnCustomerId;
  }                                                          
  

}