Fransiscus Setiawan .NET Blog » Javascript

an activex control on this page might be unsafe to interact with other parts of the page. do you want to allow this interaction?

admin — Fri, 03 Jul 2009 06:18:38 +0000

I keep getting this message “an activex control on this page might be unsafe to interact with other parts of the page. do you want to allow this interaction” when I try to access a page that use Javascript to access ActiveX Code. I’ve spent quite sometime to get rid of this error message and I found out that

The code need implement IObjectSafety Interface
You need to digitally sign the code with valid certificate

Step 1 : Detail on how to implement IObjectSafety
-Create an interface file called as IObjectSafety.vb/IObjectSafety.cs

CSharp (IObjectSafety.cs) :

[ComImport()]
[Guid("CB5BDC81-93C1-11CF-8F20-00805F2CD064")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
interface IObjectSafety {
   [PreserveSig()]
   int GetInterfaceSafetyOptions(ref Guid riid, out int pdwSupportedOptions, out int pdwEnabledOptions);
 
   [PreserveSig()]
   int SetInterfaceSafetyOptions(ref Guid riid, int dwOptionSetMask, int dwEnabledOptions);
}

Imports System.Runtime.InteropServices
 
()> _
("CB5BDC81-93C1-11CF-8F20-00805F2CD064")> _
(ComInterfaceType.InterfaceIsIUnknown)> _
Interface IObjectSafety
    ()> _
    Function GetInterfaceSafetyOptions(ByRef riid As Guid, ByRef pdwSupportedOptions As Integer, ByRef pdwEnabledOptions As Integer) As Integer
 
    ()> _
    Function SetInterfaceSafetyOptions(ByRef riid As Guid, ByVal dwOptionSetMask As Integer, ByVal dwEnabledOptions As Integer) As Integer
End Interface

in your ActiveX code you need to implement IObjectSafety

CSharp:

VB.NET:

("Fransiscus.Authentication.ClientUtility")> _
(ClassInterfaceType.AutoDual), ComSourceInterfaces("ControlEvents")> _
("0577147B-6941-4f15-9EFB-2551FEB3D6CC")> _
(True)> _
Public NotInheritable Class ClientUtility
    Implements IObjectSafety
 
 
#Region "IObjectSafety Constants"
 
    Private Const INTERFACESAFE_FOR_UNTRUSTED_CALLER As Integer = &H1
    Private Const INTERFACESAFE_FOR_UNTRUSTED_DATA As Integer = &H2
    Private Const S_OK As Integer = 0
 
#End Region
 
#Region "IObjectSafety Methods"
 
    Public Function GetInterfaceSafetyOptions(ByRef riid As System.Guid, ByRef pdwSupportedOptions As Integer, ByRef pdwEnabledOptions As Integer) As Integer Implements IObjectSafety.GetInterfaceSafetyOptions
        pdwSupportedOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER Or INTERFACESAFE_FOR_UNTRUSTED_DATA
        pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER Or INTERFACESAFE_FOR_UNTRUSTED_DATA
        Return S_OK
    End Function
 
    Public Function SetInterfaceSafetyOptions(ByRef riid As System.Guid, ByVal dwOptionSetMask As Integer, ByVal dwEnabledOptions As Integer) As Integer Implements IObjectSafety.SetInterfaceSafetyOptions
        Return S_OK
    End Function
 
#End Region

CSharp:

[ProgId("Fransiscus.Authentication.ClientUtility")] 
[ClassInterface(ClassInterfaceType.AutoDual), ComSourceInterfaces("ControlEvents")] 
[Guid("0577147B-6941-4f15-9EFB-2551FEB3D6CC")] 
[ComVisible(true)] 
public sealed class ClientUtility : IObjectSafety 
{ 
 
 
    #region "IObjectSafety Constants" 
 
    private const int INTERFACESAFE_FOR_UNTRUSTED_CALLER = 0x1; 
    private const int INTERFACESAFE_FOR_UNTRUSTED_DATA = 0x2; 
    private const int S_OK = 0; 
 
    #endregion 
 
    #region "IObjectSafety Methods" 
 
    public int GetInterfaceSafetyOptions(ref System.Guid riid, ref int pdwSupportedOptions, ref int pdwEnabledOptions) 
    { 
        pdwSupportedOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER | INTERFACESAFE_FOR_UNTRUSTED_DATA; 
        pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER | INTERFACESAFE_FOR_UNTRUSTED_DATA; 
        return S_OK; 
    } 
 
    public int SetInterfaceSafetyOptions(ref System.Guid riid, int dwOptionSetMask, int dwEnabledOptions) 
    { 
        return S_OK; 
    } 
#endregion
 
}

Step 2:
You need to obtain certificate and sign it, You also need Windows Server 2008 SDK to sign your code using SignTool.exe (type Signtool SignWizard in command prompt to follow the wizard and sign your DLL)
For more detail please open verisign website (http://www.verisign.com/support/code-signing-support/code-signing/identity-authentication.html) or click here

key event handler that compatible with all browsers using javascript

admin — Sun, 31 Aug 2008 22:41:19 +0000

This might be useful for web developer which wants to have one key event handler that compatible with all browsers.

<script language=JavaScript>
document.onkeyup = KeyCheck;      
 
function KeyCheck(e)
{
  //this is used for cross browser
  var KeyID = (window.event) ? event.keyCode : e.keyCode;
 
  switch(KeyID)
   {
 
   case 13:
    checkPostCodeSelection();
    break;      
      }
}
script>

AJAX Update Panel Timeout Issue

admin — Fri, 29 Aug 2008 07:24:59 +0000

I have an asp.net page where the page will query the report from the database. To query the report itself might cause timeout exception on the page itself before the report result is being returned from database.

You need to do it in two steps, first you need to override the script timeout only for the pageitself. put this code in your code behind

    Dim pageTimeOut As Integer     
Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init  
        pageTimeOut = Server.ScriptTimeout
 
        'this is in seconds
        Server.ScriptTimeout = 2500     
End Sub     
 
Protected Sub Page_Unload(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Unload        
 
Server.ScriptTimeout = pageTimeOut 
 
End Sub

The next step is required only if you use AJAX Update panel. Put this script on the aspx page

<script type="text/javascript">     
   Sys.WebForms.PageRequestManager.getInstance().add_endRequest(
        function (sender, args) 
        {         
             if (args.get_error() && args.get_error().name == 'Sys.WebForms.PageRequestManagerTimeoutException') 
            {            
                  // remember to set errorHandled = true to keep from getting a popup from the AJAX library itself            
                 args.set_errorHandled(true);         
             }     
        }); 
script>

Set Default value with clear text for input type=”password”

admin — Fri, 29 Aug 2008 06:18:00 +0000

Normally we have two text boxes which is user name and password. On the first load of the page we want to set the default value of user name text box becoming ‘username’ and set the default value of password text box becoming ‘password’ not ‘*******’.

Well what most of us think that we can use javascript to change the type of the input box?well I’ve got this trick to have two textboxes in the same location and swap it with “OnFocus” event

Set the default value for username text box via code behind

      Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
            txtUserName.Attributes.Add("onfocus", "JavaScript:if(this.value=='username'){this.value=''};")
            txtUserName.Attributes.Add("onblur", "JavaScript:if(this.value==''){this.value='username'};")
            txtUserName.Attributes.Add("value", "username")
 
            txtPassword.Attributes.Add("onkeydown", _
                                            "javascript:if((event.which && event.which == 13) || " _
                                            + "(event.keyCode && event.keyCode == 13))" _
                                            + " {document.getElementById('" + btnLogin.ClientID + "').click(); " _
                                            + " return false; } else return true;")
        End Sub

XML http object cross browser

admin — Fri, 29 Aug 2008 05:18:43 +0000

I believe this will be useful for everyone who wants to implement AJAX manually and make it compatible cross browser.

<script type="text/javascript"> 
 
           // cross-browser method to retrieve an XMLHttp object for asynchronous requests & responses
            function GetHTTPRequest()
            {
                var http_request = false;
 
                if (window.XMLHttpRequest) 
                { 
                    // Mozilla, Safari,...
                    http_request = new XMLHttpRequest();
 
                    if (http_request.overrideMimeType) 
                    {
                        http_request.overrideMimeType("text/xml");
                    }
                } 
                else if (window.ActiveXObject) 
                { 
                    // IE
                    try 
                    {
                        http_request = new ActiveXObject("Msxml2.XMLHTTP");
                    } 
                    catch (e) 
                    {
                        try 
                        {
                            http_request = new ActiveXObject("Microsoft.XMLHTTP");
                        } 
                        catch (e) {}
                    }
                }
 
                return http_request;
            }
 
script>

Querystring in Javascript

admin — Thu, 28 Aug 2008 21:29:22 +0000

This is a function to capture querystring in javascript. I used this javascript to control my menu dynamically.

<script type="text/javascript">
function getQueryString(strParamName){
var strReturn = "";
var strHref = window.location.href;
if ( strHref.indexOf("?") > -1 ){
var strQueryString = strHref.substr(strHref.indexOf("?")).toLowerCase();
var aQueryString = strQueryString.split("&");
for ( var iParam = 0; iParam &lt; aQueryString.length; iParam++ ){
if (
aQueryString[iParam].indexOf(strParamName.toLowerCase() + "=") > -1 ){
var aParam = aQueryString[iParam].split("=");
strReturn = aParam[1];
break;
}
}
}
return unescape(strReturn);
}
script>

Register Javascript to hide Div

admin — Thu, 28 Aug 2008 21:10:59 +0000

Sometimes people add javascript into the aspx page instead of using code behind but there is a case when we need to add javascript in the runtime using code behind. This is the example where javascript is used to provide switching of visibility based on the table visibility status. I used this technique to hide another user control when user click expand button. Client ID is required to know the real ID of the user control after rendering. In here we also add onclick event to the image tag.

if (!this.Page.IsStartupScriptRegistered("tableScript"))
{
string script = @"";
 
this.Page.RegisterStartupScript("tableScript", script);
}
 
btnExp.Attributes.Add("OnClick",
               "javascript:checkVisibility()");