Getting started with GeognoSIS SOAP

Before you develop and test a web application, create a suitable SIS Workspace Definition (SWD) containing the data you want to display in the web browser.

For this example let us call it web.swd.

TIP: See About SWDs

The first task is to set up the development environment.

Visual Studio.NET packages up code, configuration files and other resources required for an application into a project.

1. Select a New Project within Visual Studio.NET.
   
2. Select Visual Basic Projects and choose the ASP.NET Web Application option.
   
3. Specify the location where the project will be stored (eg http://localhost/GB).
   
4. Visual Studio creates a folder called GB in your localhost directory and automatically configures a corresponding virtual directory. The localhost directory is usually c:\inetpub\wwwroot. It also creates some template code and configuration files.
   
5. Copy web.swd into this directory.

After creating the development environment, add a reference to the Cadcorp GeognoSIS service.

1. In the Solution Explorer, right-click on References and choose Add Web Reference.
   
   
2. In the dialog shown, type the following into the URL text box: (ensure you enter your own GeognoSIS Admin port number if different from 4326)
   http://localhost:4326/GeognoSIS/GeognoSIS.wsdl
   
3. When the WSDL file has been located, use the Add Reference button to include a reference to GeognoSIS in the web project. The reference will be localhost by default.
4. After it has been added, a Web Reference library appears in the Solution Explorer.
   
5. Select the web reference and look at the properties form. The URL Behaviour in Visual Studio 2005 is set to the required setting of Dynamic by default.
6. The location of the Cadcorp GeognoSIS service will be included in the configuration file Web.config and may be edited freely after deployment.

The next step is to create the map window in which the SWD data is to be displayed. Visual Studio will have created a blank web page called Default.aspx.

On this form, add an image button control object from the Web Forms toolbox.

The control is named ImageButton1 by default.

Now you can add the Visual Basic code to render the SWD in a web browser.

Add code so the file reads as follows:

Imports GB.localhost

Public Class WebForm1
  Inherits System.Web.UI.Page
' The object that contains the reference to the GeognoSIS service
Dim oSis As GeognoSIS

                  … Web Form Designer generated code…

  Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) _

    Handles MyBase.Load

    ' Put user code to initialise the page here

     If oSis Is Nothing Then

        oSis = Session.Item("Sis")

        RenderSis()

     End If

  End Sub

  ' This method redraws the current map image

  Private Sub RenderSis()

    Dim md As SisMimeData

    md = oSis.Render(ImageButton1.Width.Value, ImageButton1.Height.Value, _

     "image/png")

    Session("render") = md

  End Sub

End Class

For the image button on our form to be able to render the SWD, create a new Web Form called Render.aspx.

1. Click the Add New Item button on the toolbar.
   
   
2. Create a new Web Form called Render.aspx.
   
3. Edit the Visual Basic code behind Render.aspx as follows:
   
Copy

Imports GB.localhost
Public Class Render  
    Inherits System.Web.UI.Page
        …Web Form Designer generated code…
 Private Sub Page_Load(ByVal sender As System.Object, 
ByVal e As System.EventArgs)_   
    Handles MyBase.Load    
' Put user code to initialise the page here    
    Dim md As SisMimeData    
' Retrieve the image created by the last call to Render (in WebForm1.aspx)    
md = Session("Render")    
        If Not md Is Nothing Then       
Response.AddHeader("Content-Type", md.mimeType)       
Response.BinaryWrite(md.data)    
        End If  
    End Sub
End Class

Add code to initialise GeognoSIS

Add New Item (Global Application Class) Global.asax and edit the code as follows (note that only the Session_Start method is shown):

Imports System.Web
Imports System.Web.SessionState
Imports GB.localhost
Imports System.Net
Public Class Global  
    Inherits System.Web.HttpApplication
…other auto-generated methods…
    Sub Session_Start(ByVal sender As Object, ByVal e As EventArgs)    
' Fires when the session is started    
Dim oSis As New GeognoSIS    
oSis.Credentials = New NetworkCredential("username", "password")    
oSis.LoadSwd(Server.MapPath("web.swd"))    
' web.swd is the name of the SWD that contains the data to be shown.    
Session.Item("Sis") = oSis  
    End Sub
End Class

The final step after entering all code is to inform the image control that is to be rendered.

To do this, select the control ImageButton1 and set its ImageURL property to Render.aspx.

The web project is now ready to run.

Press F5 to compile and run the site; you should now see a browser window containing a map image drawn from your SWD.