Step by Step Guide to Building a LearnDash API Integration in C#

Introduction

Hey there, fellow developer! Ready to dive into the world of LearnDash API integration? You're in the right place. LearnDash is a powerful LMS plugin for WordPress, and its API opens up a whole new realm of possibilities. In this guide, we'll walk through building a robust integration in C#. Let's get cracking!

Prerequisites

Before we jump in, make sure you've got:

• Visual Studio or your favorite C# IDE
• .NET Core 3.1 or later
• LearnDash API credentials (you've got these, right?)

Setting up the project

First things first, let's get our project off the ground:

1. Fire up Visual Studio and create a new C# Console Application.
2. Time to grab some packages. Open up the Package Manager Console and run:

Install-Package RestSharp
Install-Package Newtonsoft.Json

These will make our lives much easier when dealing with HTTP requests and JSON.

Authentication

LearnDash uses OAuth 2.0, so let's tackle that:

using RestSharp;
using Newtonsoft.Json.Linq;

public class LearnDashAuth
{
    private string _accessToken;
    private DateTime _tokenExpiry;

    public async Task<string> GetAccessToken()
    {
        if (string.IsNullOrEmpty(_accessToken) || DateTime.Now >= _tokenExpiry)
        {
            await RefreshAccessToken();
        }
        return _accessToken;
    }

    private async Task RefreshAccessToken()
    {
        var client = new RestClient("https://your-learndash-site.com/oauth/token");
        var request = new RestRequest(Method.POST);
        request.AddParameter("grant_type", "client_credentials");
        request.AddParameter("client_id", "YOUR_CLIENT_ID");
        request.AddParameter("client_secret", "YOUR_CLIENT_SECRET");

        var response = await client.ExecuteAsync(request);
        var json = JObject.Parse(response.Content);
        _accessToken = json["access_token"].ToString();
        _tokenExpiry = DateTime.Now.AddSeconds(Convert.ToDouble(json["expires_in"]));
    }
}

Making API requests

Now that we're authenticated, let's make some requests:

public class LearnDashApi
{
    private readonly LearnDashAuth _auth;
    private readonly string _baseUrl = "https://your-learndash-site.com/wp-json/ldlms/v2";

    public LearnDashApi(LearnDashAuth auth)
    {
        _auth = auth;
    }

    public async Task<string> GetCourses()
    {
        var client = new RestClient(_baseUrl);
        var request = new RestRequest("/courses", Method.GET);
        request.AddHeader("Authorization", $"Bearer {await _auth.GetAccessToken()}");

        var response = await client.ExecuteAsync(request);
        return response.Content;
    }
}

Core LearnDash API endpoints

LearnDash offers a bunch of endpoints. Here are the heavy hitters:

• Courses: /courses
• Lessons: /lessons
• Quizzes: /quizzes
• User Progress: /users/{user_id}/course-progress

Implementing key functionalities

Let's add some meat to our LearnDashApi class:

public async Task<string> EnrollUser(int userId, int courseId)
{
    var client = new RestClient(_baseUrl);
    var request = new RestRequest($"/users/{userId}/course-progress", Method.POST);
    request.AddHeader("Authorization", $"Bearer {await _auth.GetAccessToken()}");
    request.AddJsonBody(new { course_id = courseId });

    var response = await client.ExecuteAsync(request);
    return response.Content;
}

public async Task<string> UpdateUserProgress(int userId, int courseId, int lessonId, bool completed)
{
    var client = new RestClient(_baseUrl);
    var request = new RestRequest($"/users/{userId}/course-progress/{courseId}", Method.POST);
    request.AddHeader("Authorization", $"Bearer {await _auth.GetAccessToken()}");
    request.AddJsonBody(new { lesson_id = lessonId, completed = completed });

    var response = await client.ExecuteAsync(request);
    return response.Content;
}

Error handling and logging

Don't forget to wrap your API calls in try-catch blocks and log any issues:

try
{
    var courses = await _learnDashApi.GetCourses();
    Console.WriteLine(courses);
}
catch (Exception ex)
{
    Console.WriteLine($"Error: {ex.Message}");
    // Log the exception
}

Testing the integration

Unit testing is your friend. Here's a quick example using xUnit:

public class LearnDashApiTests
{
    [Fact]
    public async Task GetCourses_ReturnsValidJson()
    {
        var auth = new LearnDashAuth();
        var api = new LearnDashApi(auth);

        var result = await api.GetCourses();

        Assert.NotNull(result);
        Assert.True(JToken.Parse(result).HasValues);
    }
}

Best practices and optimization

1. Respect rate limits: LearnDash might throttle requests, so implement exponential backoff.
2. Cache responses: Store frequently accessed data to reduce API calls.
3. Use asynchronous methods: Keep your application responsive.

Conclusion

And there you have it! You've just built a solid foundation for a LearnDash API integration in C#. Remember, this is just the beginning. Explore the API docs, experiment with different endpoints, and most importantly, have fun building awesome integrations!

Keep coding, and may your builds always be successful! 🚀