Applying Browser Helper Objects
Brian
device that CE.NET is running on is a handheld scanner, and I want the
browsser to manipulate the scanner through meta tags that might appear
on a HTML page: for example
<HTML>
<HEAD>
<META HTTP-Equiv="Scanner" content="Enabled">
<META HTTP-Equiv="CODABAR" content="Enabled">
...
</HTML>
I've just started reading about "Browser Helper Objects," and I'm
curious whether this technology is something that would serve my
purpose (what I've read is in the context of adding menu items,
buttons, etc).
The BHO would interact with the software component that is provided
with the scanner.
Further, would BHO allow me to cause an event when a scan occurs? For
example, if my html page contained a form, if a barcode is scanned,
can the BHO put the data from the scan into a field and submit it to
the server?
I'm looking for the best way to do what I've described. I'm
[obviously] new at BHO, so if this is something I should pursue, I'd
appreciate advice on how to proceed.
Regards,
Brian
Igor Tandetnik
news:eaad8ee3.03050...@posting.google.com...
> I've just started reading about "Browser Helper Objects," and I'm
> curious whether this technology is something that would serve my
> purpose (what I've read is in the context of adding menu items,
> buttons, etc).
Can't really answer that, since I don't quite understand what your
purpose is. A BHO is a DLL that IE loads into its address space, and
gives access to methods and events on WebBrowser COM object representing
the browser. From there, you can also get access to and manipulate HTML
pages that get loaded into the browser. What you do with this
information is up to you, you can execute any code in your DLL.
> The BHO would interact with the software component that is provided
> with the scanner.
Is this a question or a statement?
> Further, would BHO allow me to cause an event when a scan occurs? For
> example, if my html page contained a form, if a barcode is scanned,
> can the BHO put the data from the scan into a field and submit it to
> the server?
Yes, using DHTML. A BHO can do anything a script running on the page can
do.
> I'm looking for the best way to do what I've described. I'm
> [obviously] new at BHO, so if this is something I should pursue, I'd
> appreciate advice on how to proceed.
Only you can tell if this is something you should pursue. If you do, and
you run into any specific problems, ask in the group and you are very
likely to get help on how to proceed.
--
With best wishes,
Igor Tandetnik
"For every complex problem, there is a solution that is simple, neat,
and wrong." H.L. Mencken
Brian
> "Brian" <brismi...@springmail.com> wrote in message
> news:eaad8ee3.03050...@posting.google.com...
> > I've just started reading about "Browser Helper Objects," and I'm
> > curious whether this technology is something that would serve my
> > purpose (what I've read is in the context of adding menu items,
> > buttons, etc).
>
> Can't really answer that, since I don't quite understand what your
> purpose is. A BHO is a DLL that IE loads into its address space, and
> gives access to methods and events on WebBrowser COM object representing
> the browser. From there, you can also get access to and manipulate HTML
> pages that get loaded into the browser. What you do with this
> information is up to you, you can execute any code in your DLL.
>
on a handheld barcode scanner. The browser is proprietary, it
includes the functionality I referred to (using tags to activate the
scanner, select symbologies, etc). Our application uses the vendor's
proprietary tags. We want to run this app on a CE.NET based scanner,
so I need a browser that can deal with these tags. While researching
the general topic "modifying IE behavior" I came across the subject of
BHOs.
> > The BHO would interact with the software component that is provided
> > with the scanner.
>
> Is this a question or a statement?
>
A statement. When the browser parses a tag that would affect the
scanner, the BHO would call whatever vendor-supplied function (in the
vendor's DLL) to accommodate the request.
> > Further, would BHO allow me to cause an event when a scan occurs? For
> > example, if my html page contained a form, if a barcode is scanned,
> > can the BHO put the data from the scan into a field and submit it to
> > the server?
>
> Yes, using DHTML. A BHO can do anything a script running on the page can
> do.
>
> > I'm looking for the best way to do what I've described. I'm
> > [obviously] new at BHO, so if this is something I should pursue, I'd
> > appreciate advice on how to proceed.
>
> Only you can tell if this is something you should pursue. If you do, and
> you run into any specific problems, ask in the group and you are very
> likely to get help on how to proceed.
>
My goal is to modify IE to be able to act on some additional tags
involving the underlying hardware. When I found references to BHO, I
want to make sure it'll do what I need (and whether it's the most
appropriate way to accomplish what I want to do). Thank you for your
quick response, and for any help you can offer. I feel like I'm
having to learn a whole bunch of interrelated stuff at the same time,
and don't know if I'm giving myself enough time for it all to sink in.
Can you recommend books on the subject?
Regards,
Brian
Igor Tandetnik
> involving the underlying hardware. When I found references to BHO, I
> want to make sure it'll do what I need (and whether it's the most
> appropriate way to accomplish what I want to do).
I don't see why not. If all you want to do is look for specially formed
META tags and do some custom actions based on them, a BHO can certainly
do that.
> Can you recommend books on the subject?
Assuming you are already familiar with COM, I would recommend
Programming Microsoft Internet Explorer 5 by Scott Roberts. It's pretty
much the only book on the subject.
Brian
> "Brian" <brismi...@springmail.com> wrote in message
> news:eaad8ee3.03050...@posting.google.com...
> > My goal is to modify IE to be able to act on some additional tags
> > involving the underlying hardware. When I found references to BHO, I
> > want to make sure it'll do what I need (and whether it's the most
> > appropriate way to accomplish what I want to do).
>
> I don't see why not. If all you want to do is look for specially formed
> META tags and do some custom actions based on them, a BHO can certainly
> do that.
>
> > Can you recommend books on the subject?
>
> Assuming you are already familiar with COM, I would recommend
> Programming Microsoft Internet Explorer 5 by Scott Roberts. It's pretty
> much the only book on the subject.
The book is out of print, according to Amazon; curiously, there are no
references to it at www.microsoft.com/mspress either. Any other
recommendations?
Igor Tandetnik
news:eaad8ee3.03050...@posting.google.com...
> "Igor Tandetnik" <itand...@mvps.org> wrote in message
news:<eprHQWNE...@TK2MSFTNGP12.phx.gbl>...
> > Programming Microsoft Internet Explorer 5 by Scott Roberts. It's
pretty
> > much the only book on the subject.
>
> The book is out of print, according to Amazon; curiously, there are no
> references to it at www.microsoft.com/mspress either. Any other
> recommendations?
Looks like it's still available from some merchants, e.g.
http://www.computerbooks4sale.com/site.jsp?content=product&product=1078
I don't know of any other book on the subject.