TokenUtility Class

The TokenUtility class, implemented within the TokenHandler.Utilities namespace, provides utility methods for working with tokens embedded in strings. It supports extracting tokens in the format {{TokenName}} and replacing them with values provided in a dictionary.

---

Features

1. Extract Tokens: Identify and retrieve all tokens formatted as {{TokenName}} from a given string.
2. Replace Tokens: Dynamically replace tokens in a string with single or multiple values, with optional support for looping through templates using loopSource.

---

Class Overview: TokenUtility

Namespace

namespace TokenHandler.Utilities;

Implements

ITokenHandler

The class adheres to the ITokenHandler interface, ensuring flexibility and easy integration.

---

Methods

1. ExtractToken

Extracts all tokens from a given string.

Signature

public List<string> ExtractToken(string body)

Parameters

• body: The input string containing tokens to extract.

Functionality

• Uses a regex pattern @"\{\{([^\}]+)\}\}" to identify tokens enclosed in {{ }}.
• Returns a list of tokens, including the enclosing braces.

Example

string body = "Hello {{FirstName}}, your balance is {{Balance}}.";
TokenUtility utility = new TokenUtility();
List<string> tokens = utility.ExtractToken(body);

// tokens = ["{{FirstName}}", "{{Balance}}"]

---

2. ReplaceTokens

Replaces tokens in a string with their corresponding values from a dictionary.

Signature

public string ReplaceTokens(string body, Dictionary<string, string> tokenValues, string? loopSource = null)

Parameters

• body: The string containing tokens to replace.
• tokenValues: A dictionary where:
  • Keys are tokens (e.g., {{TokenName}}).
  • Values are replacements (e.g., "John" for {{FirstName}}).
• loopSource (optional): A JSON string representing a list of templates for handling tokens with multiple values.

Functionality

1. Single Value Replacement:

   • Replaces tokens with their respective single value from tokenValues.

2. Multiple Value Replacement:

   • Splits comma-separated values for tokens.
   • Uses the loopSource parameter to format replacements dynamically.
   • Appends the results for all values into a single string.

Return Value

A string with all tokens replaced by their respective values.

Examples

Single Token Replacement

string body = "Welcome, {{UserName}}!";
var tokenValues = new Dictionary<string, string> { { "{{UserName}}", "Alice" } };

TokenUtility utility = new TokenUtility();
string result = utility.ReplaceTokens(body, tokenValues);

// Output: "Welcome, Alice!"

Multiple Token Values

string body = "<table>{{RowTemplate}}</table>";
var tokenValues = new Dictionary<string, string>
{
    { "{{RowTemplate}}", "Row1,Row2,Row3" }
};

string loopSource = "[\"<tr>{{RowTemplate}}</tr>\"]";
TokenUtility utility = new TokenUtility();
string result = utility.ReplaceTokens(body, tokenValues, loopSource);

// Output: "<table><tr>Row1</tr><tr>Row2</tr><tr>Row3</tr></table>"

---

Implementation Details

Dependencies

• System.Text.Json:
  • Used for deserializing the loopSource JSON string.
• System.Text.RegularExpressions:
  • Used for regex matching of token patterns.

---

Requirements

• Language: C#
• Framework: .NET Core or later.

---

Notes

• Tokens must be enclosed in {{ }} to be recognized by the ExtractToken method.
• Ensure loopSource is a valid JSON-encoded string representing a list of templates for multiple-value replacements.
• Handles both single and multiple values seamlessly, with support for dynamic templates.

---

License

The TokenUtility class is open for use in personal and professional projects. Contributions and enhancements are welcome.