Introduction

Request is an intermediary type that is used between handler producers and service consumers.

Class, struct and record can be used as a request. It can be named as a verb for invoking action, or noun for query.

/// <summary>Request to print record-like object as json-string</summary>
public record PrintAsJson(Object record);

Requests should be immutable, or used as such.

record PrintAsJson
{
    public object? Record { get; init; }
}

If request type is class or struct then Hash-equals comparability must be implemented. If request is record then .GetHashCode and .Equals are implemented by compiler.

    /// <summary>Request to print record-like object as json-string</summary>
    public class PrintAsJson
    {
        /// <summary>Record to print</summary>
        public readonly object record;

        /// <summary>Create request to print <paramref name="record"/></summary>
        public PrintAsJson(object record) => this.record = record;

        /// <summary>Compare to <paramref name="obj"/></summary>
        public override bool Equals(object? obj) => obj is PrintAsJson casted ? casted.record.Equals(this.record) : false;
        /// <summary>Request specific hashcode</summary>
        public override int GetHashCode() => record.GetHashCode() ^ 213;
    }
}

/// <summary>Request to print record-like object as json-string</summary>
public struct PrintAsJson
{
    /// <summary>Record to print</summary>
    public readonly object record;

    /// <summary>Create request to print <paramref name="record"/></summary>
    public PrintAsJson(object record) => this.record = record;

    /// <summary>Compare to <paramref name="obj"/></summary>
    public override bool Equals(object? obj) => obj is PrintAsJson casted ? casted.record.Equals(this.record) : false;
    /// <summary>Request specific hashcode</summary>
    public override int GetHashCode() => record.GetHashCode() ^ 213;
}

Any type can be used for a request. However, usually suitable only for narrow-purposed services as the type name doesn't indicate the requested target.

// Handler that doubles value
Action<IQuery<int, int>> h = q => q.Response.SetValue(q.Request * 2);
// Create service
IService<int, int> doubleService = Services.Create<int, int>(h);
// Double value
int x = doubleService.GetRequired(10);

[IgnoreDataMember] indicates that field or property shouls not be considered as field of request.

/// <summary>Request to print record-like object as json-string</summary>
public record PrintAsJson
{
    /// <summary></summary>
    public object? Record { get; init; }
    /// <summary>Print info</summary>
    [IgnoreDataMember]
    public String Info => $"Prints {Record} as json.";
}

[DataMember] instructs explicit order and name.

public record MyRequest
{
    [DataMember(Name = "FieldName", Order = 1)]
    public String? SomeField { get; init; }

    [DataMember(Name = "FieldName2", Order = 2)]
    public object? AnotherField { get; init; }
}

readonly struct are very efficient request types as they are pointer referenced in sync service calls.

/// <summary>Request to print record-like object as json-string</summary>
public readonly record struct PrintAsJson(Object record);

sealed classes have more efficient serialization if request is used over network or file.

/// <summary>Request to print record-like object as json-string</summary>
public sealed record PrintAsJson(Object record);

Full Example

Full example

#pragma warning disable CS0649
using System;
using System.Runtime.Serialization;
using Avalanche.Service;
using Avalanche.Utilities.Record;

public class request_index
{
    public static void Run()
    {
        {
            // <05>
            // Handler that doubles value
            Action<IQuery<int, int>> h = q => q.Response.SetValue(q.Request * 2);
            // Create service
            IService<int, int> doubleService = Services.Create<int, int>(h);
            // Double value
            int x = doubleService.GetRequired(10);
            // </05>
        }
    }

    static class _01
    {
        // <01>
        /// <summary>Request to print record-like object as json-string</summary>
        public record PrintAsJson(Object record);
        // </01>
    }


    static class _02
    {
        // <02>
        record PrintAsJson
        {
            public object? Record { get; init; }
        }
        // </02>
    }

    static class _03
    {
        // <03>
        /// <summary>Request to print record-like object as json-string</summary>
        public class PrintAsJson
        {
            /// <summary>Record to print</summary>
            public readonly object record;

            /// <summary>Create request to print <paramref name="record"/></summary>
            public PrintAsJson(object record) => this.record = record;

            /// <summary>Compare to <paramref name="obj"/></summary>
            public override bool Equals(object? obj) => obj is PrintAsJson casted ? casted.record.Equals(this.record) : false;
            /// <summary>Request specific hashcode</summary>
            public override int GetHashCode() => record.GetHashCode() ^ 213;
        }
    }
    // </03>

    static class _04
    {
        // <04>
        /// <summary>Request to print record-like object as json-string</summary>
        public struct PrintAsJson
        {
            /// <summary>Record to print</summary>
            public readonly object record;

            /// <summary>Create request to print <paramref name="record"/></summary>
            public PrintAsJson(object record) => this.record = record;

            /// <summary>Compare to <paramref name="obj"/></summary>
            public override bool Equals(object? obj) => obj is PrintAsJson casted ? casted.record.Equals(this.record) : false;
            /// <summary>Request specific hashcode</summary>
            public override int GetHashCode() => record.GetHashCode() ^ 213;
        }
        // </04>
    }


    static class _06
    {
        // <06>
        /// <summary>Request to print record-like object as json-string</summary>
        public record PrintAsJson
        {
            /// <summary></summary>
            public object? Record { get; init; }
            /// <summary>Print info</summary>
            [IgnoreDataMember]
            public String Info => $"Prints {Record} as json.";
        }
        // </06>
    }

    static class _07
    {
        // <07>
        public record MyRequest
        {
            [DataMember(Name = "FieldName", Order = 1)]
            public String? SomeField { get; init; }

            [DataMember(Name = "FieldName2", Order = 2)]
            public object? AnotherField { get; init; }
        }
        // </07>
    }

    static class _08
    {
        // <08>
        /// <summary>Request to print record-like object as json-string</summary>
        public readonly record struct PrintAsJson(Object record);
        // </08>
    }

    static class _09
    {
        // <09>
        /// <summary>Request to print record-like object as json-string</summary>
        public sealed record PrintAsJson(Object record);
        // </09>
    }
}
#pragma warning restore CS0649