StarBlog Development Notes (11): Implementing Visit Statistics

Series Articles

• Developing a Blog Project with .NetCore: StarBlog - (1) Why Write Your Own Blog?
• Developing a Blog Project with .NetCore: StarBlog - (2) Environment Setup and Project Creation
• Developing a Blog Project with .NetCore: StarBlog - (3) Model Design
• Developing a Blog Project with .NetCore: StarBlog - (4) Batch Import of Markdown Blog Posts
• Developing a Blog Project with .NetCore: StarBlog - (5) Starting to Build the Web Project
• Developing a Blog Project with .NetCore: StarBlog - (6) Page Development: Blog Post List
• Developing a Blog Project with .NetCore: StarBlog - (7) Page Development: Post Detail Page
• Developing a Blog Project with .NetCore: StarBlog - (8) Displaying the Category Hierarchy
• Developing a Blog Project with .NetCore: StarBlog - (9) Batch Image Import
• Developing a Blog Project with .NetCore: StarBlog - (10) Image Waterfall Layout
• Developing a Blog Project with .NetCore: StarBlog - (11) Implementing Visit Statistics
• ...

Preface

Back from the Dragon Boat Festival holiday, my blog still isn't live. Seeing how well all the experts' sites are doing, I feel a faint sense of urgency—time to hurry up and write some code~!

The previous articles have already implemented the basic features of the blog site. We're just one step away from going live, but there are still some minor details that have a big impact on site operations or user experience and must be completed, such as:

• Site visit statistics
• Image hosting

In that order, this article will first solve the visit statistics problem.

When it comes to visit statistics, the well-known options are Google Analytics or Baidu Analytics. The former can't be used in China, so the latter should be the only choice. But considering the feature gap between the two as well as that company's reputation, for my little site, I'd rather implement one myself~

Implementation

It shouldn't be hard to implement. To enable statistics and analysis, we first need to record data. The recorded content includes the user's IP, device, visit path, and visit time. Then, by analyzing this data, we can get the view/visit counts for each article, image, and category.

To record this data, we need to process every request the user makes. In AspNetCore there are several implementations, such as Filter, such as Middleware

Here I chose the middleware approach

PS: I saw an article online about implementing visit statistics in Django. The author wrote a method and called it once in every endpoint—it made my scalp tingle

Inject the Repo in the middleware, then on every request save the IP, device, request path, and other data to the database. This looks like it would have some impact on performance, but considering a blog site's concurrency should be quite small, the resulting performance loss should be negligible. (To be honest, I'm just being lazy)

We'll optimize later if we hit a performance bottleneck~

Model Definition

Create a new VisitRecord.cs in StarBlog.Data/Models

To save space, comments and such aren't included; see github for the full code

public class VisitRecord {
    public int Id { get; set; }
    public string Ip { get; set; }
    public string RequestPath { get; set; }
    public string? RequestQueryString { get; set; }
    public string RequestMethod { get; set; }
    public string UserAgent { get; set; }
    public DateTime Time { get; set; }
}

Write a Middleware

Create a new VisitRecordMiddleware.cs in StarBlog.Web/Middlewares

public class VisitRecordMiddleware {
    private readonly RequestDelegate _next;

    public VisitRecordMiddleware(RequestDelegate requestDelegate) {
        _next = requestDelegate;
    }

    public Task Invoke(HttpContext context, IBaseRepository<VisitRecord> visitRecordRepo) {
        var request = context.Request;
        var response = context.Response;

        visitRecordRepo.InsertAsync(new VisitRecord {
            Ip = context.Connection.RemoteIpAddress?.ToString().Split(":").Last(),
            RequestPath = request.Path,
            RequestQueryString = request.QueryString.Value,
            RequestMethod = request.Method,
            UserAgent = request.Headers.UserAgent,
            Time = DateTime.Now
        });
        
        return _next(context);
    }
}

There's one thing to note here: my visitRecordRepo is injected in the Invoke method. Why not inject it in the constructor?

Because the constructor of an AspNetCore middleware is Singleton, so it can only inject Singleton services, while FreeSQL's Repository is Scoped. Injecting it in the constructor would throw an error

So it can only be injected in the Invoke method~

Using the Middleware

Edit StarBlog.Web/Programs.cs and add the middleware configuration

app.UseMiddleware<VisitRecordMiddleware>();

PS: This project is based on .Net6, where Startup and Program have been merged into one; if you're on .NetCore 3.1 or below, configure the middleware in Startup.cs.

Results

I haven't done any analysis based on the visit records yet, so I can only screenshot the database

OK, next we can analyze this data (I'll write about that later in the admin backend development section)