Philiprehberger.StringTemplate

Named placeholder string interpolation from objects and dictionaries with formatting and defaults.

Installation

dotnet add package Philiprehberger.StringTemplate

Usage

using Philiprehberger.StringTemplate;

var result = Template.Render("Hello, {name}!", new { name = "World" });
// "Hello, World!"

Render from Object

using Philiprehberger.StringTemplate;

var user = new { FirstName = "Alice", LastName = "Smith" };
var result = Template.Render("Welcome, {FirstName} {LastName}!", user);
// "Welcome, Alice Smith!"

Render from Dictionary

using Philiprehberger.StringTemplate;

var values = new Dictionary<string, object?>
{
    ["product"] = "Widget",
    ["quantity"] = 5
};

var result = Template.Render("Order: {quantity}x {product}", values);
// "Order: 5x Widget"

Format Specifiers

using Philiprehberger.StringTemplate;

var data = new { price = 19.99m, date = new DateTime(2026, 3, 21) };
var result = Template.Render("Price: {price:C2}, Date: {date:yyyy-MM-dd}", data);
// "Price: $19.99, Date: 2026-03-21"

Detect Placeholders

using Philiprehberger.StringTemplate;

Template.HasPlaceholders("Hello, {name}!");       // true
Template.HasPlaceholders("No placeholders here"); // false
Template.HasPlaceholders("Escaped {{braces}}");   // false

Extract Placeholder Names

using Philiprehberger.StringTemplate;

var names = Template.ExtractPlaceholders("Hello, {name}! You have {count} items.");
// ["name", "count"]

var formatted = Template.ExtractPlaceholders("{price:C2} on {date:yyyy-MM-dd}");
// ["price", "date"]

API

Template

Method	Description
Render(template, values)	Replace placeholders using an object's public properties
Render(template, values)	Replace placeholders using a dictionary
Render(template, values, options)	Replace placeholders with custom missing-key behavior
HasPlaceholders(template)	Returns true if the template contains any {name} placeholders
ExtractPlaceholders(template)	Returns a string[] of distinct placeholder names in order of appearance

TemplateOptions

Property	Type	Default	Description
MissingKeyBehavior	string	"Throw"	How to handle missing keys: "Throw", "Empty", or "LeaveTemplate"
DefaultValue	string	""	Fallback value when MissingKeyBehavior is "Empty"

Development

dotnet build src/Philiprehberger.StringTemplate.csproj --configuration Release

Support

If you find this project useful:

⭐ Star the repo

🐛 Report issues

💡 Suggest features

❤️ Sponsor development

🌐 All Open Source Projects

💻 GitHub Profile

🔗 LinkedIn Profile

License

MIT