Extension methods

The CrispyWaffle.Extensions namespace holds a set of static helper classes, mostly extension methods, for common chores: converting strings to numbers and dates, cleaning and reshaping text, reading enum attributes, flattening exception chains, rounding integers, reflecting over types and reading XML.

Each class has no state and no dependencies to wire up. Add using CrispyWaffle.Extensions; and the methods appear on the types they extend.

How it works

Most methods are forgiving. They return a neutral value (0, string.Empty, the original input, or false) for null, empty or whitespace input instead of throwing. The exceptions to this rule are listed in each table: for example ToDateTime throws on empty input, and Levenshtein does not check for null.

A few methods depend on legacy code pages that .NET (Core) does not load by default:

• RemoveDiacritics and LevenshteinInvariantCulture use code page 1251.
• ToSafeUrl uses ISO-8859-8.

On .NET Core and .NET 5 or later, register the code pages provider once at startup before you call these methods. The library does not do it for you.

using System.Text;

Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);

Parsing methods (ToInt32, ToInt64, ToDecimal, ToMonetary, TryToDateTime) use the current culture unless noted.

Getting started

using System;
using CrispyWaffle.Extensions;

var quantity = "1,250".ToInt32();             // 1250 under en-US; 0 if parsing fails
var due = "tomorrow".ToDateTime();            // DateTime.Today.AddDays(1)
var active = "s".ToBoolean();                 // true: matches the default "S", case-insensitive
var title = "republica federativa do brasil".ToCamelCase(); // "Republica Federativa Do Brasil"
var slots = 15.RoundUp();                     // 20
var place = 22.ToOrdinal();                   // "22nd"

Reference

ConversionExtensions

public static class ConversionExtensions — conversions between strings, numbers, dates, booleans, bytes, JSON and XML.

StringExtensions

public static class StringExtensions — cleaning, formatting, encoding and comparing strings. All methods are marked [Pure].

EnumExtensions

public static class EnumExtensions — reads and resolves the HumanReadable and InternalValue attributes on enum fields. See Attributes.

ExceptionExtensions

public static class ExceptionExtensions — flattens an exception chain and formats it. The logging infrastructure's default exception handler uses these methods; see Logging.

MathExtensions

public static class MathExtensions — rounds integers to a multiple.

TypeExtensions

public static class TypeExtensions — reflection helpers.

XmlExtensions

public static class XmlExtensions — helpers for XmlReader, XmlDocument and XmlNode.

Examples

Parse user input safely

ToInt32 and TryToDateTime never throw, so they suit form and CSV input.

using System;
using CrispyWaffle.Extensions;

var page = "abc".ToInt32();                    // 0
if ("31/12/2020".TryToDateTime(out var date))  // dd/MM/yyyy fallback
{
    Console.WriteLine(date.ToString("yyyy-MM-dd")); // 2020-12-31
}

Console.WriteLine(1000m.ToMonetary(new System.Globalization.CultureInfo("en-US"))); // $1,000.00

Map enums to display and storage values

using CrispyWaffle.Attributes;
using CrispyWaffle.Extensions;

var label = OrderStatus.Pending.GetHumanReadableValue();   // "Waiting for payment"
var code = OrderStatus.Shipped.GetInternalValue();         // "SH"
var status = EnumExtensions.GetEnumByInternalValueAttribute<OrderStatus>("sh"); // OrderStatus.Shipped

public enum OrderStatus
{
    [HumanReadable("Waiting for payment")]
    [InternalValue("WP")]
    Pending = 0,

    [HumanReadable("Shipped")]
    [InternalValue("SH")]
    Shipped = 1,
}

Flatten an exception chain

using System;
using System.Collections.Generic;
using CrispyWaffle.Extensions;
using CrispyWaffle.Log.Providers;

try
{
    throw new InvalidOperationException("Outer", new ArgumentException("Inner"));
}
catch (Exception ex)
{
    var queue = ex.ToQueue(out var innerTypes);   // Inner first, then Outer
    var text = queue.GetMessages("Orders", new List<ILogProvider>());
    Console.WriteLine(text);
}

Compare strings ignoring accents and case

using System.Text;
using CrispyWaffle.Extensions;

Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);

var distance = "Three".LevenshteinInvariantCulture("tree"); // 1

See also

• Attributes for HumanReadable, InternalValue and the query string attributes
• Utilities for QueryStringBuilder and IUpdateable
• Validations for the regular expressions used by the string helpers
• pt-BR internationalization for Brazilian-specific conversions