Hackathon - Programmatically update a Sitecore Item

ComputeUpdate.cs

private bool ComputeUpdate(Item item, ItemModel itemModel)
{
    bool success = false;

    var fieldsToRevert = itemModel.Fields.Where(x => x.RevertToStandardValue);

    using (new Sitecore.SecurityModel.SecurityDisabler())
    {
        try
        {
            item.Editing.BeginEdit();

            foreach (var sField in fieldsToRevert)
            {
                var field = item.Fields.FirstOrDefault(x => x.ID.ToString().Trim().ToLower() == sField.Id.Trim().ToLower());

                if (field == null)
                {
                    Log.Error("Failed to revert field to standard values, field was not found on item", this);
                    continue;
                }

                field.Value = field.GetStandardValue();

                if (field.Value.Contains("$"))
                {
                    Sitecore.Data.MasterVariablesReplacer replacer = Sitecore.Configuration.Factory.GetMasterVariablesReplacer();
                    if (replacer != null)
                        replacer.ReplaceItem(item);
                }                        
            }

            success = true;
        }
        catch (Exception ex)
        {
            Log.Error(ex.Message, ex, this);
            throw ex;
        }
        finally
        {
            item.Editing.EndEdit();
        }
    }

    return success;
}