Can't set up 2-step authentication for WebDataSource

[Dmitry]

Hello

I'm using the WebDataSource component from Web Report Designer, and I want to receive data from our REST API. 

On endpoints with no auth it works fine and the data gets loaded. But when I try to use 2-step auth (get token and pass it to api), I get a popup from web data source Wizard:

Error

Could not get preview.. An error has occurred. Object reference not set to an instance of an object.

 

And the debugger shows this:

WebDesigner Warning: 0 : Newtonsoft.Json.JsonReaderException: Error reading JObject from JsonReader. Path '', line 0, position 0.
   at Newtonsoft.Json.Linq.JObject.Load(JsonReader reader, JsonLoadSettings settings)
   at Newtonsoft.Json.Linq.JObject.Parse(String json, JsonLoadSettings settings)
   at Telerik.Reporting.Processing.WebServiceDataSource.ErrorParsers.ErrorManager.ParseJson(String responseContent)
WebDesigner Error: 0 : Object reference not set to an instance of an object.
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceClient.SendCore(IWebServiceRequestSettings settings, AuthenticationHeaderValue authHeader, HttpClient httpClient, HttpClientHandler httpClientHandler)
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceClient.GetTwoStepAuthorizationHeader(WebServiceTwoStepAuthentication processedAuth)
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceClient.Request(WebServiceDataSource processedDS)
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceDataProvider.GetRemoteRawData(WebServiceDataSource processedDS)
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceDataProvider.get_RawData()
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceSchemaAdapter.AddDataMeasures(SimpleDataModel model)
   at Telerik.Reporting.Processing.Data.SimpleDataProvider`1.GetSchemaCore()
   at Telerik.Reporting.Processing.Data.DataProvider`1.Telerik.Reporting.Processing.Data.IDataProvider.GetSchema()
   at Telerik.WebReportDesigner.Services.ConnectionsService.GetDataModel(DataSourceInfo dsi)
WebDesigner Error: 0 : Object reference not set to an instance of an object.
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceClient.SendCore(IWebServiceRequestSettings settings, AuthenticationHeaderValue authHeader, HttpClient httpClient, HttpClientHandler httpClientHandler)
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceClient.GetTwoStepAuthorizationHeader(WebServiceTwoStepAuthentication processedAuth)
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceClient.Request(WebServiceDataSource processedDS)
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceDataProvider.GetRemoteRawData(WebServiceDataSource processedDS)
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceDataProvider.get_RawData()
   at Telerik.Reporting.Processing.WebServiceDataSource.WebServiceSchemaAdapter.AddDataMeasures(SimpleDataModel model)
   at Telerik.Reporting.Processing.Data.SimpleDataProvider`1.GetSchemaCore()
   at Telerik.Reporting.Processing.Data.DataProvider`1.Telerik.Reporting.Processing.Data.IDataProvider.GetSchema()
   at Telerik.WebReportDesigner.Services.ConnectionsService.GetDataModel(DataSourceInfo dsi)

Auth URL is `https://localhost:5001/api/Account/Token2` and it should return plain text string with the token.

Request body is

{
  "login": "admin",
  "password": "foobar"
}

I click next-next in the Wizard and on the last step get the error above.

Why does not it work ??

[Dimitar]

The error message suggests that the issue occurs when the WebServiceDataSource attempts to make the POST request. When making a POST request, it is necessary to add a Content-Type request header with a value of application/json. This is likely the request for the token.

You may refer to step 5 of the solution in the Pass Parameter in WebServiceDataSource with Post Method - Telerik Reporting KB article for details on how to add the Content-Type request header.

Note that if the response is a simple plain-text string, the Token Path field should be left empty so that the entire login response is treated as the token by the component - WebServiceDataSource Component at a Glance - Telerik Reporting.

If that does not help, would it be possible to attach a copy of the report alongside an accessible Web API endpoint that we can use to test locally?

I look forward to hearing back from you.