Handy extension methods for RenderingParameters in Sitecore MVC

RenderingParametersExtensions.cs

using Sitecore.Data;
using Sitecore.Data.Fields;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Mvc.Presentation;
using Sitecore.Resources.Media;

namespace Foundation.Extensions
{
    public static class RenderingParametersExtensions
    {
        public static string GetImageUrl(this RenderingParameters parameters, ID fieldId)
        {
            string result = string.Empty;
            Item field = GetField(fieldId);
            string numberBackgroundImageParameterValue = parameters?[field.Name];
            if (!string.IsNullOrWhiteSpace(numberBackgroundImageParameterValue))
            {
                ImageField imageField = new ImageField(
                    new Field(fieldId, field),
                    numberBackgroundImageParameterValue);
                if (imageField.MediaItem != null)
                {
                    result = MediaManager.GetMediaUrl(imageField.MediaItem);
                }
            }

            return result;
        }

        public static string GetValueOrDefault(this RenderingParameters parameters, ID fieldId, string defaultValue)
        {
            string result = defaultValue;
            string fieldName = GetFieldName(fieldId);
            if (!string.IsNullOrWhiteSpace(fieldName) && !string.IsNullOrWhiteSpace(parameters?[fieldName]))
            {
                result = parameters[fieldName];
            }

            return result;
        }

        private static Item GetField(ID fieldId)
        {
            Item result = Sitecore.Context.Database.GetItem(fieldId);
            if (result == null)
            {
                Log.Error($"Could not find the field '{fieldId}'.", typeof(RenderingParametersExtensions));
            }

            return result;
        }

        private static string GetFieldName(ID fieldId)
        {
            string result = null;
            Item field = GetField(fieldId);
            if (field != null)
            {
                result = field.Name;
            }

            return result;
        }
    }
}