What's wrong with the following code to capture the Browser type?

Discussion in 'Javascript' started by Greener, Oct 8, 2003.

  1. Greener

    Greener Guest

    Hi, I need help badly. Can you do client-side programming instead of
    server-side to capture the Browser type info? If this is the case,
    what's wrong with the following?


    <script language="JavaScript">
    function doWord(file)
    {

    if (navigator.userAgent.indexOf("MSIE")!=-1)
    {
    var w = new ActiveXObject("Word.Application");
    if (w != null)
    {
    w.Visible = true;

    w.Documents.Open(file);

    }
    }
    else
    {
    document.write(...)
    }

    }
    </script>

    but it doesn't work.
    So I am wondering about what's wrong. Thanks for your advice.

    Helena
     
    Greener, Oct 8, 2003
    #1
    1. Advertisements

  2. Greener

    Lee Guest

    Greener said:
    It should have some sort of error handling code in case w == null,
    but other than that, it works for me. What do you mean when you
    say "it doesn't work". What does it do, instead of opening Word?
     
    Lee, Oct 8, 2003
    #2
    1. Advertisements

  3. I assume that was intended to start "you can not do it, . . . ".
    Yes, Konqueror (so probably Safari), IceBrowser and Web Browser 2.0. In
    fact I think that test probably only rules out Opera and Gecko browsers
    as it seems to be common these days for non-IE browsers to be
    implementing a document.all collection.
    <snip>

    I would have thought that, since the desire is to call the ActiveXObject
    constructor, the pertinent test would be for the existence of the
    ActiveXObject constructor:-

    if(window.ActiveXObject){
    // new ActiveXObject can be called.
    }
    -or-
    if(typeof ActiveXObject != 'undefined'){
    // new ActiveXObject can be called.
    }

    Following the principal that you feature/object test as close to the
    problem as possible.

    However, with IceBrowser being an example of at least one browser that
    has a fake ActiveXObject constructor it becomes very important to test
    the object returned to ensure that it is an object. The OP's - if (w !=
    null) - is a good start but it would also be worth checking that the
    object has the methods and properties that the script wants to call (eg.
    Documents.Open) in case the ActiveXObject constructor is a fake that
    just returns a standard JavaScript object.

    But then there are the ActiveX user preferences. My IE 6 will not allow
    any scripting of ActiveX over the internet so even if it could be
    determined by other means that the browser was IE 6 the script would
    still not execute on it.

    Just to add to the confusion, I recently read in a netscape.public.*
    group of development work on ActiveX for windows Gecko browsers with a
    new "GeckoActiveXObject" constructor. So maybe this script would not be
    limited to just IE in the future. Though I got the impression that the
    Gecko ActiveX support would be for custom ActiveX controls and not
    Microsoft ones such a Word.Application.

    Richard.
     
    Richard Cornford, Oct 8, 2003
    #3
  4. <snip>

    Its not as if I don't do that myself more often than I should.
    (or do I? ;-)

    Richard.
     
    Richard Cornford, Oct 8, 2003
    #4
  5. Greener

    Greener Guest

    First of all, thanks to all for the assistances!

    When I meant it didn't work, I saw on the left bottom corner right
    above the toolbar, "Error on Page", after i click a button to do the
    following function.
     
    Greener, Oct 8, 2003
    #5
  6. Greener

    Greener Guest

    Thanks a lot. I tried to insert the following piece of code to my code
    in several possible places: if(window.ActiveXObject){
    // new ActiveXObject can be called.
    }


    <script language="JavaScript">
    function doWord(file)
    {
    if(window.ActiveXObject){
    if (navigator.userAgent.indexOf("MSIE")!=-1)
    {
    var w = new ActiveXObject("Word.Application");
    if (w != null)
    {
    w.Visible = true;

    w.Documents.Open(file);

    }
    }
    else
    {
    document.write(...)
    }
    }
    }
    </script>


    It still didn't work. Should I also try the other way you mentioned?
    That is,

    if(typeof ActiveXObject != 'undefined'){
    // new ActiveXObject can be called.
    }


    What went wrong? How to make it work? Bear with me and sorry for my
    ignorance.
     
    Greener, Oct 8, 2003
    #6
  7. Greener

    Lee Guest

    Greener said:
    If you're writing JavaScript in Internet Explorer, you should configure
    it to show you the details of your errors. I don't use IE often enough
    to know how to do that, myself.
     
    Lee, Oct 8, 2003
    #7
  8. The quick way to activate IE error messages is to wait until the little
    yellow triangle shows up in the browser status bar, double click on it
    and, when the message box appears, check the "always show errors"
    checkbox it contains.

    Otherwise it is in one of the tabs under "Internet Options" in the menu.

    Richard.
     
    Richard Cornford, Oct 8, 2003
    #8
  9. You have missed the point of Randy's original reply to your post. You do
    not _ever_ make decisions based on the userAgent string. The only
    information that can be gleaned from the contents of the user agent
    string is what the user agent string contains, and that gets you
    nowhere.

    The point is to replace the meaningless userAgent string based test with
    one that has a genuine relationship to your problem. So, assuming that
    the required task is to instanciate an ActiveX objet the meaningful
    _first_ test is to see if the browser has an ActiveXObject constructor.
    Then you can call the ActiveXObject constructor, but the test tells you
    nothing more than that the ActiveXObject constructor exists, the outcome
    of the call still needs to be tested (assuming that the call itself does
    not throw and exception).

    To know what went wrong I would need to know what happened, such things
    as error messages, the context of testing and so on.

    Richard.
     
    Richard Cornford, Oct 8, 2003
    #9
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.