Automate a Markdown links page with Pinboard and C#

This is my contribution for the C# Advent Calendar, a collection of awesome C# posts throughout December. Check it out!

I run a weekly newsletter called The .NET Stacks. If you’ve read this blog for any period of time you know this, thanks to my shameless plugs. (Feel free to subscribe!) I love it and enjoy writing it every week, but it can take up a lot of my time.

The biggest time spent is generating all the great community links. Luckily, I found a way to automate this process. I can click a button, and a console app writes all my links to my Markdown file. Then, all I have to do is fill in the rest of the newsletter.

It’s down to a two-step process, really: throughout the week, I add links to my Pinboard, then my app writes them to a Markdown file.

This post will show off how you can populate a Markdown links page using Pinboard and C#.

How I curate links

The act of getting links has to be somewhat manual. I could say “whenever Person X posts, save it” but what if this person goes nuts and writes a post criticizing Santa Claus? My links are curated—while I don’t agree with everything I share, I do want them to be relevant and useful. After getting links from my various RSS feeds and link aggregators, I can start the automation.

Where do I store my bookmarks? I’m a big fan of Pinboard. For not even $2 a month, it’s a no frills, fast, and secure way to save bookmarks. No ads, no tracking, and a great feature set. And it comes with an API! I knew this would save me hours a month and it makes the investment well worth it.

After exploring the API docs, I found a hacky—but useful!—way to save me loads of time.

These are all retrievable fields from the API. The title, which is my name, is anything before the link and the description is my link text.

After I get all my links in, usually by Sunday, I’m ready to generate the links. Let’s look at how I make that happen.

Use C# to generate Markdown links page

This is all done with a simple console app. It isn’t enterprise-ready; it’s for me. So I didn’t go crazy with any of it—the point of this is something quick to get my time back.

To interact with the Pinboard API, I’m using the Pinboard.net NuGet package, a wonderful C# wrapper that makes connecting to the API so easy. Thanks to Shrayas Rajagopal for your work on this!

I was able to use C# 9 top-level programs to avoid the Main method ceremony.

At the top of the program, I do the following:

using var pb = new PinboardAPI("my-api-key");
var bookmarksList = await pb.Posts.All();
await WriteMarkdownFile(bookmarksList);

I connect to Pinboard using my API key and get all my bookmarks (referred to as Posts). Then, everything happens in my WriteMarkdownFile method.

I define the filePath on my system, and include today’s date in the name.

var filePath = $"C:\\path\\to\\site\\_drafts\\{DateTime.Now:yyyy-MM-dd}-dotnet-stacks.markdown";

All my links are categorized by tags. To avoid hardcoding, I have a Tags class to store the tag names (what I use in Pinboard) and the heading (what is in the newsletter):

public static class Tags
{
    public const string AnnouncementsHeading = "📢 Announcements";
    public const string AnnouncementsTag = "Announcements";

    public const string BlazorHeading = "😎 Blazor";
    public const string BlazorTag = "Blazor";

    // and so on and so forth
}

Back to the WriteMarkdownFile method, I store these in a dictionary. Depending on the week, I change the order of these, so I want that flexibility. (I could have sorting logic, I suppose.)

var tagInfo = new Dictionary<string, string>
{
    { Tags.AnnouncementsHeading, Tags.AnnouncementsTag },
    { Tags.CommunityHeading, Tags.CommunityTag },
    { Tags.BlazorHeading, Tags.BlazorTag },
    { Tags.DotNetCoreHeading, Tags.DotNetCoreTag },
    { Tags.CloudHeading, Tags.CloudTag },
    { Tags.LanguagesHeading, Tags.LanguagesTag },
    { Tags.ToolsHeading, Tags.ToolsTag },
    { Tags.XamarinHeading, Tags.XamarinTag },
    { Tags.PodcastsHeading, Tags.PodcastsTag },
    { Tags.VideoHeading, Tags.VideoTag }
};

Using a classic StringBuilder, I start to write out the file. I begin with my Jekyll front matter and the beginning heading, which is always the same:

var sb = new StringBuilder("---");
sb.AppendLine();
sb.AppendLine($"date: \"{DateTime.Now:yyyy-MM-dd}\"");
sb.AppendLine("title: \"The .NET Stacks: <fill in later>\"");
sb.AppendLine("tags: [dotnet-stacks]");
sb.AppendLine("comments: false");
sb.AppendLine("---");
sb.AppendLine();

sb.AppendLine("## 🌎 Last week in the .NET world");
sb.AppendLine();
sb.AppendLine("### 🔥 The Top 3");
sb.AppendLine();

Here’s the fun part, where I print out all the bookmarks:

foreach (var entry in tagInfo)
{
    sb.AppendLine($"### {entry.Key}");
    sb.AppendLine();

    foreach (string bookmark in GetBookmarksForTag(entry.Value, bookmarksList))
    {
        sb.AppendLine($"- {bookmark}");
    }

    sb.AppendLine();
}

For each tag in the dictionary, I create a heading with the tag text, then do a line break. Then, for each bookmark object, I have a method that retrieves a filtered list based on the tag. For each bookmark, I construct a string with how I want to format the link, then add it to a list.

static string[] GetBookmarksForTag(string tag, AllPosts allBookmarks)
{
    var filteredBookmarks = allBookmarks.Where(b => b.Tags.Contains(tag));
    var filteredList = new List<string>();

    foreach (var bookmark in filteredBookmarks)
    {
        var stringToAdd = $"{bookmark.Description} [{bookmark.Extended}]({bookmark.Href}).";
        filteredList.Add(stringToAdd);
    }

    return filteredList.ToArray();
}

Once I’m done with all the tags, I use a TextWriter to write to the file itself.

static string[] GetBookmarksForTag(string tag, AllPosts allBookmarks)
{
    var filteredBookmarks = allBookmarks.Where(b => b.Tags.Contains(tag));
    var filteredList = new List<string>();

    foreach (var bookmark in filteredBookmarks)
    {
        var stringToAdd = $"{bookmark.Description} [{bookmark.Extended}]({bookmark.Href}).";
        filteredList.Add(stringToAdd);
    }

    return filteredList.ToArray();
}

In just 76 lines of code, I was able to come up with something that saves me a ridiculous amount of time. There are other improvements to be made, like storing backups to Azure Storage, but I like it.

Here’s the full code, if you’d like:

using pinboard.net;
using pinboard.net.Models;
using PinboardToMarkdown;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using var pb = new PinboardAPI("my_api_key");
var bookmarksList = await pb.Posts.All();
await WriteMarkdownFile(bookmarksList);

static async Task WriteMarkdownFile(AllPosts bookmarksList)
{
    var filePath = $"C:\\path\\to\\site\\_drafts\\{DateTime.Now:yyyy-MM-dd}-dotnet-stacks.markdown";

    var tagInfo = new Dictionary<string, string>
    {
          { Tags.AnnouncementsHeading, Tags.AnnouncementsTag },
          { Tags.CommunityHeading, Tags.CommunityTag },
          { Tags.BlazorHeading, Tags.BlazorTag },
          { Tags.DotNetCoreHeading, Tags.DotNetCoreTag },
          { Tags.CloudHeading, Tags.CloudTag },
          { Tags.LanguagesHeading, Tags.LanguagesTag },
          { Tags.ToolsHeading, Tags.ToolsTag },
          { Tags.XamarinHeading, Tags.XamarinTag },
          { Tags.PodcastsHeading, Tags.PodcastsTag },
          { Tags.VideoHeading, Tags.VideoTag }
    };

    var sb = new StringBuilder("---");
    sb.AppendLine();
    sb.AppendLine($"date: \"{DateTime.Now:yyyy-MM-dd}\"");
    sb.AppendLine("title: \"The .NET Stacks: <fill in later>\"");
    sb.AppendLine("tags: [dotnet-stacks]");
    sb.AppendLine("comments: false");
    sb.AppendLine("---");
    sb.AppendLine();

    sb.AppendLine("## 🌎 Last week in the .NET world");
    sb.AppendLine();
    sb.AppendLine("### 🔥 The Top 3");
    sb.AppendLine();

    foreach (var entry in tagInfo)
    {
        sb.AppendLine($"### {entry.Key}");
        sb.AppendLine();

        foreach (string bookmark in GetBookmarksForTag(entry.Value, bookmarksList))
        {
            sb.AppendLine($"- {bookmark}");
        }

        sb.AppendLine();
    }

    await using TextWriter stream = new StreamWriter(filePath);
    await stream.WriteAsync(sb.ToString());
}

static string[] GetBookmarksForTag(string tag, AllPosts allBookmarks)
{
    var filteredBookmarks = allBookmarks.Where(b => b.Tags.Contains(tag));
    var filteredList = new List<string>();

    foreach (var bookmark in filteredBookmarks)
    {
        var stringToAdd = $"{bookmark.Description} [{bookmark.Extended}]({bookmark.Href}).";
        filteredList.Add(stringToAdd);
    }

    return filteredList.ToArray();
}

Wrap up

In this post, I showed how you can use Pinboard and C# to send links to a Markdown page automatically. I showed why I like to use Pinboard, and we also stepped through the code to see how it all works.

If you have any suggestions, please let me know!