QueryParametersAttribute

Namespace: RA.Utilities.Integrations.Attributes

The [QueryParameters] attribute marks a partial class or record as a strongly-typed container of query string parameters.

At compile time, the package's source generator emits a partial declaration that implements IQueryStringRequest for the class, mapping each public instance property to a query string key-value pair.

⚙️ How It Works

Given:

[QueryParameters]
public partial class GetProductsQuery
{
    public int? CategoryId { get; init; }
    public string? Search { get; init; }
    public int[] Ids { get; init; } = [];
}

the generator produces (conceptually):

public partial class GetProductsQuery : IQueryStringRequest
{
    public QueryParams QueryStringValues()
    {
        var values = new QueryParams();

        // CategoryId → only when not null
        // Search    → only when not null
        // Ids       → one pair per element: ?Ids=1&Ids=2

        return values;
    }

    public string ToQueryString(string action) => ...;
}

Callers can then pass the object directly to BaseHttpClient:

await client.GetAsync<Product>("products", new GetProductsQuery { CategoryId = 5 });
// GET /products?CategoryId=5

📋 Rules

• The class must be partial — and so must all of its containing types (the generator reports error RPIG001 otherwise).
• Only public instance properties with a getter are mapped; static properties and indexers are ignored.
• null values are skipped. Non-nullable value types (e.g. int, bool) have no null state and are always emitted — declare them as int?/bool? to make them optional.
• bool values are formatted as true/false; DateTime/DateTimeOffset use the round-trip "o" format; other scalars use invariant culture formatting.
• Collections (IEnumerable<T>, arrays) produce repeated keys; dictionaries produce one entry per key-value pair, using the entry's key.
• Use [QueryParameterName] on a property to override the emitted key.
• Classes that already implement IQueryStringRequest (or declare a QueryStringValues/ToQueryString member) are skipped to avoid duplicate members.

🧠 Summary

[QueryParameters] turns a plain DTO into a compile-time-safe, self-mapping query string model — no hand-written mapping code, no runtime reflection, and full IntelliSense support at the call site.