How TransCAD for the Web Works

You can quickly create simple applications without programming by adding existing controls to a web form and linking them to your geographic data. Developers can extend the functionality of an application by modifying the source code for the existing controls, often by adding just a few lines of code.

The following diagram shows the structure of a typical web form map.aspx. It contains three controls: LocateControl, MapControl and InfoControl. LocateControl lets users find street addresses. MapControl displays the map image and lets users zoom and pan. InfoControl displays information about map features into a DataGrid HTML table.

Each control is composed of three editable files: The HTML layout (e.g., MapControl.ascx), the .NET source code that executes the logic behind the control (MapControl.ascx.vb) and the XML parameter setting file that link the control to your geographic data (MapControl.config). You edit the parameter setting file visually in TransCAD for the Web, and the other two files in an editor such as Visual Studio.NET, Dreamweaver, or even NotePad.