NLightTemplate is a lightweight .NET string template renderer.
This was born out of a recurring need (and subsequent fractured code bases) for server-side rendered, user-defined templates. Our research and testing of the available template engines failed to find one that was lightweight and provided the functionality we required. We rolled our own and this is the result of internal iterations on the concept.
- Lightweight
- Reflection-based POCO key:value replacement
- Nested enumeration
- Dot notation property accessors for reference types
- Familiar syntax (using default configuration)
PM> Install-Package NLightTemplate
> dotnet add package NLightTemplate
No dependencies
NETStandard.Library (>= 1.6.1)
The renderer uses token replacement with curly braces { and } surrounding the key by default.
A global custom configuration may be set at any time using the fluent interface. This should only be done once during the application initialization process.
StringTemplate.Configure.OpenToken("<%").CloseToken("%>").ForeachToken("fe");A custom configuration may be set on an individual call by passing a configuration object into the Render method.
var cfg = new FluentStringTemplateConfiguration()
.OpenToken("<%")
.CloseToken("%>")
.ForeachToken("fe")
.ExposeConfiguration();
//or
var cfg = new StringTemplateConfiguration
{
OpenToken = "<%",
CloseToken = "%>",
ForeachToken = "fe"
};
var body = StringTemplate.Render(template, customer, cfg);Version 1.0.2 added support for string.Format syntax for padding and format.
var d = DateTime.Now;
var s = string.Format("{0,15:d MMM yyyy}", d);
var t = StringTemplate.Render("{MyDate,15:d MMM yyyy}", new { MyDate = d });
Console.WriteLine(s == t); // outputs True public class Customer
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string FullName => $"{FirstName} {LastName}";
} var customer = new Customer
{
FirstName = "John",
LastName = "Doe"
};
Console.WriteLine(StringTemplate.Render("Hello {FullName}!", customer)); //Produces "Hello John Doe!"
Console.WriteLine(StringTemplate.Render("Hello {FirstName} {LastName}!", customer)); //Produces "Hello John Doe!"IEnumerable properties can be enumerated by specifying the open {foreach PropertyName} and close {/foreach PropertyName} tags. Everything in between will be repeated, applying the token replacement for each. Property names are locally scoped within the foreach tags.
public class Order
{
public int Id { get; set; }
public int CustomerId { get; set; }
public DateTime Placed { get; set; }
public DateTime? Shipped { get; set; }
public List<OrderDetail> Details { get; set; }
public double SubTotal => Details?.Sum(d => d.SubTotal) ?? 0;
}
public class OrderDetail
{
public int Id { get; set; }
public int OrderId { get; set; }
public Product Product { get; set; }
public int Quantity { get; set; }
public double UnitPrice { get; set; }
public double SubTotal => UnitPrice * Quantity;
}
public class Product
{
public int Id { get; set; }
public string Name { get; set; }
public bool IsInStock { get; set; }
public override string ToString() => $"{Name} {(IsInStock ? "In Stock" : "Unavailable")}";
} Console.WriteLine(StringTemplate.Render(
"{foreach Orders}Order Id: {Id} ${SubTotal}\r\n{/foreach Orders}",
customer));
/*
Outputs:
Order Id: 123 $24.25
Order Id: 124 $107.79
*/ string template = @"{foreach Orders}
Order {Id} placed at {Placed} and Shipped {Shipped}
QTY Product Price SubTotal
{foreach Details}
{Quantity} {Product.Name} {UnitPrice} {SubTotal}
{/foreach Details}
Total: {SubTotal}
{/foreach Orders}";
Console.WriteLine(StringTemplate.Render(template, customer));
/*
Outputs:
Order 123 placed at 9/20/2017 2:46:15 AM and Shipped
QTY Product Price SubTotal
1 Blue Shirt 12.35 12.35
2 White Socks 5.95 11.9
Total: 24.25
Order 124 placed at 9/22/2017 2:46:15 AM and Shipped
QTY Product Price SubTotal
1 Red Shoes 59.99 59.99
4 White Shirt 11.95 47.8
Total: 107.79
*/Any reference properties will have their properties available using dot notation.
The above example shows {Product.Name} writing out the Name property on the Product property of the OrderDetail instance.
string template = @"
Thank you {FullName} for your recent order(s):
email: {emailAddress}
something unknown: {dunno}
{foreach Orders}
Order {Id} placed at {Placed} and Shipped {Shipped}
QTY Product Price SubTotal
{foreach Details}
{Quantity} {Product.Name} {UnitPrice} {SubTotal}
{/foreach Details}
Total: {SubTotal}
{/foreach Orders}
{foreach Orders}
This is the 2nd list for Order: {Id}
QTY Product Price SubTotal
{foreach Details}
{Quantity} {Product} {UnitPrice} {SubTotal}
{/foreach Details}
Total: {SubTotal}
{/foreach Orders}";
var extras = new Dictionary<string, object>() { { "emailAddress", "someone@home.com" } };
Console.WriteLine(StringTemplate.Render(template, BuildDemoCustomer(), extras));- Validate and write tests for custom implementations of IEnumerable
- Add support for
string.Formatstyle format patterns and padding (added in v1.0.2)