Basic Overview

Shortcodes processor for .NET with focus on performance and simplicity.

Features

• Parses and renders shortcodes.
• Supports async shortcode to execute database queries and async operations more efficiently under load.
• Named and positioned arguments.

Contents

• Sample usage
• Used by

Sample usage

Don't forget to include the using statement:

using Shortcodes;

Predefined shortcodes

var processor = new ShortcodesProcessor(new NamedShortcodeProvider
{
    ["hello"] = (args, content, ctx) => new ValueTask<string>("Hello world!")
});

Console.WriteLine(await processor.EvaluateAsync("This is an [hello]"));

Which results in

This is an Hello world!

Named arguments

Arguments can contain any character, but need to be quoted either with ' or " if they contain spaces. Strings can use standard string escape sequences like \u03A9 and \n.

var processor = new ShortcodesProcessor(new NamedShortcodeProvider
{
    ["bold"] = (args, content, ctx) => 
    {
        var text = args.Named("text");
        
        return new ValueTask<string>($"<b>{text}</b>");
    }
});

Console.WriteLine(await processor.EvaluateAsync("[bold text='bold text' 1234]"));

Content arguments

Shortcodes using opening and closing tags can access their inner content.

var processor = new ShortcodesProcessor(new NamedShortcodeProvider
{
    ["bold"] = (args, content, ctx) => 
    {
        return new ValueTask<string>($"<b>{content}</b>");
    }
});

Console.WriteLine(await processor.EvaluateAsync("[bold]bold text[/bold]"));

For single tags, the content is null. It means that you can detect if a shortcode was used with a closing tag, even if the inner content is empty.

Positional arguments

If an argument doesn't have a name, an default index can be used.

var processor = new ShortcodesProcessor(new NamedShortcodeProvider
{
    ["bold"] = (args, content, ctx) => 
    {
        var text = args.NamedOrDefault("text");
        
        return new ValueTask<string>($"<b>{text}</b>");
    }
});

Console.WriteLine(await processor.EvaluateAsync("[bold 'bold text']"));

<b>bold text</b>

Named and positional arguments can be mixed together. Each time an argument doesn't have a name, the index is incremented.

var processor = new ShortcodesProcessor(new NamedShortcodeProvider
{
    ["bold"] = (args, content, ctx) => 
    {
        var text = args.At(0);
        
        return new ValueTask<string>($"<b>{text}</b>");
    }
});

Console.WriteLine(await processor.EvaluateAsync("[bold id='a' 'some text']"));

<b>some text</b>

Escaping tags

In case you want to render a shortcode instead of evaluating it, you can double the opening and closing braces.

[[bold] some text to show [/bold]]

Will then be rendered as

[bold] some text to show [/bold]

And for single tags:

[[bold 'text']]

Will be rendered as

[bold 'text']

In case several braces are used, and they are balanced, a single one will be escaped.

[[[bold 'text']]]

Will be rendered as:

[[bold 'text']]

Not that unbalanced braces won't be escaped.

[[[[bold 'text']]

Will be rendered as

[[[[bold 'text']]

Context object

A Context object can be passed when evaluating a template. This object is shared across all shortcodes

A common usage is to pass custom data that might be used by some shortcodes, like the current HttpContext if a template is running in a web application and needs to access the current request.

Another usage is to use it as a bag of values that can be shared across shortcodes.

// From a Startup.cs class

var processor = new ShortcodesProcessor(new NamedShortcodeProvider
{
    ["username"] = (args, content, ctx) => 
    {
        var httpContext = (HttpContext)ctx["HttpContext"];
        
        return new ValueTask<string>(httpContext.User.Identity.Name);
    }
});

app.Run((httpContext) =>
{
    var context = new Context(){ ["HttpContext"] = httpContext };
    var result = await processor.EvaluateAsync("The current user is [username]", context);
    return context.Response.WriteAsync(result);
});

The current user is admin