Change color based on value

Question

I have a number of fields where I want to display the data in red if it is expired.

<%= Html.Encode(String.Format("{0:d}", Model.Subcontract.insurance_GL))%>

If the date is less than today's date, then I'd want it to display in red. What is the best way to do this?

EDIT This is for my Detail View. It's not in a grid. It's just a listing of the fields for the individual Subcontract. There's, insurance_GL, insurance_AL, insurance_WC, etc. Different fields, not the same field repeating in a grid.

Answer 1

I would add a class to the field if the value is less than zero.

So I'm not sure what types of HTML elements are wrapping your field values, but using your example I would do this:

<span class="<%=(Model.Subcontract.insurance_GL < 0 ? "red" : "black")%>"
  <%= Html.Encode(String.Format("{0:d}", Model.Subcontract.insurance_GL))%>
</span>

Answer 2

It really depends on how you are rendering your data in the client page. Are you using asp.net forms, with a GridView? Are you generating the html for your data yourself?

I usually go about this with css classes. I'll have a class for flagged items, like this:

.late
{
    color: #f00;
}

And in the code behind, where my html is being generated, if you're creating all the html yourself:

foreach(Item item in items)
{
    string cls = "";
    if (item.IsLate)
        cls = " class='late'";
    html += "<div" + cls + ">" + item.Text + "</div>";
}

That will create <div>Item1</div> for a non-late item, and <div class="late">Item2</div> for a late item. You can also have a class for non-late items, if you want them to be styled a certain way too. Easy enough.

If the items you're flagging are server controls, and you're not creating the html yourself, you can assign a class to them:

if (item1.IsLate)
    myTextBox.CssClass = "late";

If your data is bound to a GridView, you can have an event handler for RowDataBound, and do something like this:

protected void gridview_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        Item item = e.Row.DataItem as Item;
        if (item.IsLate)
            e.Row.CssClass = "late";
    }
}

You could also apply the styling to an individual cell in the GridView:

// 3rd cell
e.Row.Cells[2].CssClass = "late";

Hope one of these fits your scenario.