Use a custom data reader

To create a custom data reader that is compatible with Tosca Cloud, code a DLL file that fits the following requirements:

• Base your customization on .NetStandard 2.0, so it works for both our Windows execution and Linux execution.

• Reference the Tricentis.DataIntegrity.GenericDataSource.dll.

  After you run a Data Integrity test case on Windows, the Tosca Cloud Launcher downloads this DLL to the directory %LOCALAPPDATA%\TRICENTIS\Launcher\TBox\<latest TBox version>\Tricentis Tosca Data Integrity.

  You can also download the DLL here.

• Specify the class attribute name of your reader under DataSourceReader. Tosca Cloud uses this name to distinguish between different custom readers.

• Use the Initialize method to allow the application to receive key-value pairs for a test step and store the information that it gets from that test step locally. For example, the key is FilePath and the value is the actual file path D:\TestFile.csv.

• Use the Connect method to allow the application to create a connection. For example, to open a specific file and store the reference to it locally.

• Use the Cancel method to ensure that the application doesn't get stuck if the reading operation has to be canceled.

• Implement Interface ICustomDataReader as shown in the following example.

using System;
using System.Collections.Generic;
using System.IO;
using Tricentis.DataIntegrity.GenericDataSource;
namespace CustomReaderExtension
{
    [DataSourceReader("CustomCSVReader")]
    public class CustomCSVReaderExample : ICustomDataReader {
        public IDictionary<string, string> parameters;
        public StreamReader fileStream;
        public void Initialize(IDictionary<string, string> parameters) {
            this.parameters = parameters;
        }
        public void Connect() {
            fileStream = new StreamReader(parameters["FilePath"]);
        }
        public string[] GetColumnNames() {
            return ReadLine();
        }
        public string[] GetNextRow() {
            return ReadLine();
        }
        public bool HasMoreRows() {
            return !fileStream.EndOfStream;
        }
        public void Cancel() {
            //Not implemented, filereader will only be closed.
        }
        public void Disconnect() {
            fileStream.Close();
        }
        public string[] ReadLine() { 
            return fileStream.ReadLine().Split(',');
        }
    }
}

To use a custom data reader in your test, you first need to upload it to Tosca Cloud. To do so, follow these steps:

1. Go to Configurations > Uploads > Custom Data Readers > Upload file.

   Note that only users with administrator rights can upload files to Tosca Cloud.

2. Select Custom from the Choose a data reader to upload dropdown menu.

3. Select your custom data reader from your local files.

After you upload a custom data reader, you are able to see it in your Custom data readers list in Tosca Cloud. It is also available to use in all Data Integrity tests you create with the Load Data into Caching Database or Complete Row by Row Comparison modules. To use a custom data reader with these modules, fill out the test step value Custom Data Reader as follows:

• For Class Attribute Name, enter the name of the reader that is under DataSourceReader in the reader's DLL file.

• Under Parameters, set up your parameters as they are specified in the reader's DLL file.