Soenneker.Utils.String 4.0.3171

Soenneker.Utils.String

String helpers for query strings, lightweight model binding, URL extraction, templates, compound identifiers, and Base64-encoded JSON.

Installation

dotnet add package Soenneker.Utils.String

Most helpers are static and can be called directly:

using Soenneker.Utils.String;

string id = StringUtil.ToCombinedId("customer", "42");
string? returnUrl = StringUtil.GetQueryParameter(
    "https://example.test/callback?returnUrl=%2Faccount%3Ftab%3Dsecurity",
    "returnUrl");

ToCombinedId removes null and empty parts and joins the rest with :. It does not escape delimiters, so do not use it where parts containing : must remain distinguishable.

Query strings

GetQueryParameter returns the first matching value from any string containing a ?. Names and values use form-style decoding, where percent escapes are decoded and + becomes a space. A key without = has an empty value, matching is case-sensitive, and URL fragments are excluded.

GetQueryParameters accepts an absolute URI and returns an ordinal, case-sensitive dictionary. The first occurrence of a duplicate decoded key wins. It returns null when the input is not an absolute URI or has no query parameters.

Dictionary<string, string>? values = StringUtil.GetQueryParameters(
    "https://example.test/search?q=red+shoes&page=2");

// values["q"] == "red shoes"

Binding query strings

Register IStringUtil when you need the reflection-based binder or email-domain extraction through dependency injection:

using Soenneker.Utils.String.Abstract;
using Soenneker.Utils.String.Registrars;

services.AddStringUtilAsSingleton();

public sealed class SearchService(IStringUtil strings)
{
    public SearchRequest Parse(string query) => strings.ParseQueryString<SearchRequest>(query);
}

ParseQueryString<T> creates T, matches query keys to public writable properties without regard to case, and converts values with Convert.ChangeType. Unknown keys are ignored. It is intended for simple scalar properties; failed conversions throw, and nullable, collection, or complex properties require a different binding strategy.

ParseQueryStringUsingJson<T> is the tolerant static alternative. It builds a string-valued dictionary and deserializes it through Soenneker.Utils.Json; conversion failures return null and are written to the optional logger.

Other helpers

• GetDomainFromEmail returns the text after the last @ when both sides are non-empty. It does not validate an email address.
• ExtractUrls finds URL-shaped substrings. Treat the results as candidates, not validated or trusted destinations.
• BuildStringFromTemplate replaces brace-delimited placeholders sequentially with non-null values. Placeholder names are informational; unmatched placeholders remain in the result, and braces are not escaped.
• ConvertBase64JsonToObject<T> decodes standard Base64 containing UTF-8 JSON. Invalid Base64 or JSON throws. It does not accept the Base64Url alphabet.

ConvertBase64JsonToObject<T> clears the portion of its pooled decode buffer before returning it, but decoded objects and input strings remain managed memory. Do not treat it as a complete secret-erasure mechanism.