Question

I’ve been asked to improve a ASP.Net C# page. It currently shows a years worth of daily prices for a product. The page looks similar to a wall planner, with each input control showing a price for that day.

The page will be used to change the price of this product for that year. Currently the ‘wall planner’ table control is being generated cell-by-cell in the code behind.

There is a lot of code used to implement this but essentially it does the following.

A table is built… dynamically

1. New Table control defined
2. 12 new TableRow controls defined (months)
3. Each row has 31 TableCell controls added to it (Each with a unique id e.g. cell_yy_mm_dd)

Its filled with data

1. 365 days of prices are retrieved from the database (Price and Date).
2. Foreach used to loop over the dataset
3. Date checked with the TableCells id. If there is a match, a new TextBox is added to the cell.

This is causing a huge strain on the server (specifically memory usage). It seems so over engineered there must be a better way of doing it!

What would be a better method to implement such functionality?

Answer 1

This is how I would solve it. Using two repeaters, one for the months and one for the days.
Using the current calendar I can than from code generate the months and the days using linq and left join with the values from the db on the Date.

Code

//The values from the DB
var values = new List<DateValue>()
{ 
    new DateValue(){ Date = new DateTime(2012, 1, 12), Value = 5000 },  
    new DateValue(){ Date = new DateTime(2012, 11, 15), Value = 3000 }
};

var year = DateTime.Now.Year;
var cal = System.Threading.Thread.CurrentThread.CurrentCulture.Calendar;

//Generate the months and dates and left join with the values from the DB
var q = from month in Enumerable.Range(1, cal.GetMonthsInYear(year))
        select new
        {
            Dates = from date in Enumerable.Range(1, 
                        cal.GetDaysInMonth(year, month))
                        .Select(day => new DateTime(year, month, day))
                    join tmp in values on date equals tmp.Date into g
                    from value in g.DefaultIfEmpty()
                    select new
                    {
                        Date = date,
                        Value = value == null ? new Nullable<Decimal>() : value.Value
                    }
        };

//bind the query to the outer repeater
repMonths.DataSource = q;
repMonths.DataBind();

DTO filled from DB

public class DateValue
{
     public DateTime Date { get; set; }
     public decimal Value { get; set; }
}

ASPX

<table border="1">
      <asp:Repeater runat="server" ID="repMonths">
            <ItemTemplate>
                <tr>
                    <asp:Repeater runat="server" ID="repDays" DataSource='<%# DataBinder.Eval(Container.DataItem, "Dates") %>'>
                        <ItemTemplate>
                            <td>
                                <%# DataBinder.Eval(Container.DataItem, "Value")  %>
                            </td>
                        </ItemTemplate>
                    </asp:Repeater>
                </tr>
            </ItemTemplate>
      </asp:Repeater>
</table>