Applet as DSO in Browser example? MSIE only?

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Richard Maher - 10 Mar 2007 00:21 GMT

Hi,

Recently on the web I came across documentation discussing Data Source
Objects (DSO) in relation to browser and html functionality (in particular
the ability to declare a Java applet as a data source that can be used with
any or the HTML tags that take the src="" attribute). I find it interesting
and potentially *very* useful and would like to know more, so if anyone can
answer any of the following questions that would be great: -

1) Do you have an example of an Applet functioning as an applet to something
like a <Table> that I can see?

2) Is this a MicrosoftIE-only feature? I can't find it in other html tag
reference sites. (I'm using w3schools as a sort of yardstick; is that less
than optimal?) What do other browsers do? Is Microsoft deprecating this
along with other Java stuff?

3) I've searched in c.l.j.p/c.l.javascript and the only references to DSOs
appear to be server based (or data sources other than Applet) I'm guessing
they're entirely different beasts; is that correct?

4) Anyone ever passed a BufferedImage over to Javascript for display on a
web page? (I know it'd be single threaded and all those little .GIFs and
.JPEGs are designed for parallel http webservers, but think of a blob in a
database that has an employee photo of geological survey or something. . .)

Thanks for any help!

Regards Richard Maher

PS. I am already passing result set <options>s back to a <select> list quite
happily; it's the tighter integration between the html tags and my socket
that I'm striving for here.

One of the places I've been looking: -
http://msdn.microsoft.com/library/default.asp?url=/workshop/author/databind/data
sources.asp

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VK - 10 Mar 2007 19:00 GMT

On Mar 10, 4:24 am, "Richard Maher" <maher...@hotspamnotmail.com>
wrote:

> Recently on the web I came across documentation discussing Data Source
> Objects (DSO) in relation to browser and html functionality

That was a long waiting ;-) - DSO / Data Binding is supported since IE
4.0
All relevant tags and attributes are part of HTML 4 DTD

> (in particular
> the ability to declare a Java applet as a data source that can be used with
> any or the HTML tags that take the src="" attribute).

I don't agree with such concept description.
DSO is part of Microsoft Data Binding technology. First you define a
an object on your page connected with tabular data source on your
server (static or dynamic). It is made by using data binding ActiveX
object coming with IE installation. The reference to Java applet on
MSDN is a bit mysterious to me. I guess for IE 4/5 Microsoft allowed
to use their JVM for bridging to the needed ActiveX, so people could
use either <object> or <applet> depending on personal preferences. In
either case it is definitely in relation to the Microsoft own JVM
which is not provided any more. It has nothing to do with Sun plugin.

After DSO object properly initialized, you map (bind) particular data
columns in the source to relevant columns in HTML table template. This
way you don't need to build the table itself - it gets filled and
updated automatically on source data change. Later DSO Microsoft
proposed IXMLHTTPRequest object. Current AJAX is IXMLHTTPRequest
pulled out by rivals out of sense and context from Microsoft Data
Binding. They got the motor but they left everything else out. Instead
XHR got transformed into some "hidden browser" used for manual data
retrieval and manual page updates. Seems very silly and ineffective
but I guess developers didn't have any choice for cross-browser
solutions. Besides Gecko browsers with XBL support all other UAs stock
in the middle age of the data treatment and still cannot get onto
mainstream.

> I find it interesting
> and potentially *very* useful and would like to know more, so if anyone can
> answer any of the following questions that would be great: -
>
> 1) Do you have an example of an Applet functioning as an applet to something
> like a <Table> that I can see?

For DSO / data binding hardly such sample can be provided - see above.
It is easy to imagine an applet or flash retrieving data from server
and then communication with the host document DOM to display such
data. But it really adds nothing to a regular ajaxoid made with
javascript.

> 2) Is this a MicrosoftIE-only feature?

As DSO / Data Binding / relevant HTML tags and attributes - yes, it is
Windows IE only feature.

> I can't find it in other html tag
> reference sites. (I'm using w3schools as a sort of yardstick; is that less
> than optimal?)

Use the producer manuals instead:
http://msdn.microsoft.com/workshop/author/databind/data_binding.asp

> 3) I've searched in c.l.j.p/c.l.javascript and the only references to DSOs
> appear to be server based (or data sources other than Applet) I'm guessing
> they're entirely different beasts; is that correct?

Not sure if I understood the question properly. DSO is external to the
document. It is a bridge between a tabular data server-side and data
binding capable HTML "display" client-side. Because of the technology
remained IE-only you will not find many discussions of it on clj. You
will have much better results on microsoft.public.* forums

> 4) Anyone ever passed a BufferedImage over to Javascript for display on a
> web page?

What is BufferedImage in context of "passed over to javascript"?
Javascript doesn't have byte-level access to images. All you can pass
to it is image URL.

Reply to this Message

Richard Maher - 17 Mar 2007 12:13 GMT

Hi VK,

Thanks for the detailed reply!

> That was a long waiting ;-) - DSO / Data Binding is supported since IE

Doin' my best to catch up.

> > (in particular
> > the ability to declare a Java applet as a data source that can be used with
> > any or the HTML tags that take the src="" attribute).
>
> I don't agree with such concept description.

That's exactly what my rose-coloured glasses (or beer-goggles) told me it
did :-)

> In
> either case it is definitely in relation to the Microsoft own JVM
> which is not provided any more. It has nothing to do with Sun plugin.> >

2) Is this a MicrosoftIE-only feature?

> As DSO / Data Binding / relevant HTML tags and attributes - yes, it is
> Windows IE only feature.

OK, that's all very disappointing.

> It is easy to imagine an applet or flash retrieving data from server
> and then communication with the host document DOM to display such
> data.

Certainly is.

> But it really adds nothing to a regular ajaxoid made with
> javascript.

You seem confident.

Cheers Richard Maher

> On Mar 10, 4:24 am, "Richard Maher" <maher...@hotspamnotmail.com>
> wrote:
[quoted text clipped - 75 lines]
> Javascript doesn't have byte-level access to images. All you can pass
> to it is image URL.

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Applet as DSO in Browser example? MSIE only?

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