Response Model

ResponseModel.cs

using System;
using System.Collections.Generic;
using System.Linq;

/// <summary>
/// Response Model
/// </summary>
public class ResponseModel<T>
{
    /// <summary>
    /// Response Model builder
    /// </summary>
    public ResponseModel()
    {
        this.Errors = new Dictionary<string, List<string>>();
    }

    /// <summary>
    /// Response Model builder
    /// </summary>
    public ResponseModel(T data)
    {
        this.Data = data;
    }

    /// <summary>
    /// Response Model builder
    /// </summary>
    /// <param name="errors"></param>
    public ResponseModel(Dictionary<string, List<string>> errors)
    {
        this.Errors = errors;
    }

    /// <summary>
    /// Response Model builder
    /// </summary>
    /// <param name="parameterError"></param>
    /// <param name="error"></param>
    public ResponseModel(string parameterError, string error)
    {
        this.Errors = new Dictionary<string, List<string>>
        {
            { parameterError, new List<string> { error } }
        };
    }

    /// <summary>
    /// Data
    /// </summary>
    public T Data { get; private set; }

    /// <summary>
    /// Errors
    /// </summary>
    public Dictionary<string, List<string>> Errors { get; private set; }

    /// <summary>
    /// Add error
    /// </summary>
    /// <param name="parameter"></param>
    /// <param name="error"></param>
    /// <returns></returns>
    public ResponseModel<T> AddError(string parameter, string error)
    {
        if (error == null || string.IsNullOrEmpty(parameter)) 
            return this;

        if (this.Errors.Keys.Contains(parameter))
        {
            this.Errors.TryGetValue(parameter, out var errorList);
            errorList?.Add(error);
        }
        else
            Errors.Add(parameter, new List<string> { error });

        return this;
    }

    /// <summary>
    /// Add error
    /// </summary>
    /// <param name="parameter"></param>
    /// <param name="errors"></param>
    /// <returns></returns>
    public ResponseModel<T> AddError(string parameter, List<string> errors)
    {
        if (errors == null || errors.Count == 0 || string.IsNullOrEmpty(parameter)) 
            return this;

        if (this.Errors.Keys.Contains(parameter))
        {
            this.Errors.TryGetValue(parameter, out var errorList);
            if(errorList != null)
            foreach (var error in errors)
                errorList.Add(error);
        }
        else
            Errors.Add(parameter, errors);

        return this;
    }

    /// <summary>
    /// Contain error description
    /// </summary>
    /// <param name="parameter"></param>
    /// <returns></returns>
    public bool ContainErrorParamter(string parameter)
    {
        return this.Errors.Keys.Contains(parameter);
    }

    /// <summary>
    /// Contain error description
    /// </summary>
    /// <param name="errorDescription"></param>
    /// <returns></returns>
    public bool ContainErrorDescription(string errorDescription)
    {
        return this.Errors.Values.Contains(new List<string> { errorDescription });
    }

    /// <summary>
    /// Union
    /// </summary>
    /// <param name="model"></param>
    /// <returns></returns>
    public ResponseModel<T> Union(ResponseModel<T> model)
    {
        this.Errors = this.Errors.Concat(model.Errors).ToDictionary(s => s.Key, s => s.Value);
        return this;
    }

    /// <summary>
    /// Has error?
    /// </summary>
    /// <returns></returns>
    public bool HasError() => this.Errors != null && this.Errors.Count > 0;
}