String Token Replacer in C#

Imagine you have a template text where you need to replace placeholders with actual values:

Hello {{name}}! Your order number {{orderNumber}} is ready for shipment.

In this example, the tokens inside double curly braces ({{token}}) are placeholders that will be replaced with real values.

Here’s how you can create a simple token replacer in C#.

using System;
using System.Collections.Generic;

namespace TokenReplacerExample
{
    public static class TokenReplacer
    {
        // Method to replace tokens in a string using a dictionary of tokens
        public static string ReplaceTokens(this string template, Dictionary<string, string> tokenValues)
        {
            if (tokenValues == null) return template;

            // Loop through each token in the dictionary and replace the placeholder in the string
            foreach (var token in tokenValues)
            {
                // Replace the token placeholder with the actual value
                template = template.Replace("{{" + token.Key + "}}", token.Value);
            }

            return template;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            // Dictionary of tokens and their corresponding replacement values
            var tokenValues = new Dictionary<string, string>
            {
                { "name", "Alice" },
                { "orderNumber", "987654" },
                { "shippingDate", "January 15, 2025" }
            };

            // Template string with tokens to be replaced
            string template = "Hello {{name}}, your order {{orderNumber}} will be shipped on {{shippingDate}}.";

            // Replace tokens using the ReplaceTokens method
            string result = template.ReplaceTokens(tokenValues);

            // Output the result
            Console.WriteLine(result);
        }
    }
}

In this example:

• ReplaceTokens method: This extension method for strings takes a dictionary where keys are the token names (e.g., name, orderNumber), and the values are the replacement strings. It loops through the dictionary, replacing each {{token}} in the string with the corresponding value.
• Template String: The string you want to modify has placeholders like {{name}}, {{orderNumber}}, etc., which are replaced by the actual values in the dictionary.

Given the following dictionary:

var tokenValues = new Dictionary<string, string>
{
    { "name", "Alice" },
    { "orderNumber", "987654" },
    { "shippingDate", "January 15, 2025" }
};

And the template string:

string template = "Hello {{name}}, your order {{orderNumber}} will be shipped on {{shippingDate}}.";

The output would be:

Hello Alice, your order 987654 will be shipped on January 15, 2025.

This method is very flexible and allows you to easily replace tokens in any string with the corresponding values from a dictionary.