JScript .NET, Part IX: Code Behind: The Code Behind add Consumer - Doc JavaScript

JScript .NET, Part IX: Code Behind

The Code Behind add Consumer

Let's look at a more complex example now. In Column 113 we called the add Web service from within the ASP.NET page. We now want to split the ASP.NET page to presentation (.aspx) and Code Behind (.js). Here is the Code Behind:

import System.Diagnostics;
import System.Xml.Serialization;
import System;
import System.Web.Services.Protocols;
import System.ComponentModel;
import System.Web.Services;
import calcService;

package ASPPlus {

  class codeBehind extends System.Web.UI.Page {

    public var resultControl :
      System.Web.UI.WebControls.TextBox;
      public var first : System.Web.UI.WebControls.TextBox;
    public var second : System.Web.UI.WebControls.TextBox;

	public function Page_Load(sender:Object,
    E:System.EventArgs) : void {
      resultControl.Enabled = false;
    }

    public function Submit_Click(sender:Object,
      E:System.EventArgs) : void {
      var result : String;
      var webService : simpleCalc;
      webService = new simpleCalc();

      result = webService.add(int.Parse(first.Text),
      int.Parse(second.Text)).ToString();
      resultControl.Text = result;
    }

  }

}

We first import all kinds of basic classes. Most of them are not used, but they don't interfere either, and provides you with a base of classes which more often than not will be used somewhere. The calcService namespace is the more important one. This namespace includes the add Web service definition. Please refer to Column 113 to see how we compiled the add Web service into a dll file.

The Code Behind defines the ASPPlus namespace and the codeBehind class. Included in the class are three properties and two functions. The three properties are those of the three ASP:TextBox controls on the ASP.NET page (two input numbers and a result). The functions are Page_Load() and Submit_Click().

Recall from our Hello World example that the Page_Load() function is called automatically when the page loads. The only action we do in this function is to disable the resultControl ASP:TextBox. It means that the user cannot enter anything in this text box, as it is used to display the result of the addition of the two input numbers.

The Submit_Click() function is called when the corresponding button is clicked in the ASP.NET page. We first define the string result and the object of type simpleCalc, webService. We call the add Web service, and put the result in result. We finally assign result to the Text property of resultControl.