Yes. The section in the documentation about RESTXQ shows how XQuery can be used
to handle HTTP requests. The part about REST shows a way to execute queries
(programs) and commands over HTTP. BaseX comes with a servlet that can run in a
web server. The servlet is a java class that is executed by the java vm that is
running the web server. The servlet also runs the native basex server. BaseX
also includes a web server that can be used instead of a web server outside of
BaseX.
The section in the documentation about Java bindings shows how you can create
modules that implement XQuery functions in java (or whatever JVM language). In
xquery like:
Import module namespace d = “ http: //duke-software.com/xml “;
d:compute()
The function d:compute() could be implemented in java so you are executing java
by invoking the function.
The XQuery that implements a web application could use the module that includes
the java functions that interact with the mainframe to communicate with a
service listening in the mainframe. That is driven by the web application.
To cause basex to handle communication from the second task, you could use
threads but instead of what I said in the last post, it might be better to have
the program that interacts with the mainframe run as a separate OS service
that handles data coming from the mainframe and data coming from basex.
The user’s browser calls the web service that runs within basex (directly or
from another web application). That web service includes calls to xquery
functions that directly communicate with the mainframe over sockets or the
separate OS service.
The second task could communicate with the OS service that executes XQuery in
basex and receives data from BaseX which it send to the mainframe.
If you implement xquery functions in java you probably would need to look at
the examples in the basex source in the basex-examples directory.
Kendall
On 10/19/17, 2:24 PM, "basex-talk-boun...@mailman.uni-konstanz.de on behalf of
Dave Day" <basex-talk-boun...@mailman.uni-konstanz.de on behalf of
david....@duke-software.com> wrote:
It is your last sentence that I don't understand, due to my lack of
knowledge of most all things Basex.
The Java code that does the communication would be a function that is
called from within a running Basex server?
-- Dave
On 10/19/2017 4:12 PM, Kendall Shaw wrote:
> If the desktop code can be java, then it could be like:
>
> A web application running in basex serves the web page that is UI for the
user.
>
> That web application uses the module that you wrote in java to connect
and send and receive data with the mainframe for your 2 tasks. The module is
used in the web application as xquery functions.
>
> Kendall
>
> On 10/19/17, 1:57 PM, "basex-talk-boun...@mailman.uni-konstanz.de on
behalf of Dave Day" <basex-talk-boun...@mailman.uni-konstanz.de on behalf of
david....@duke-software.com> wrote:
>
> I googled websockets, and sure enough, the RFC talks about the HTTP
> protocol. I'm not going to try to code that.
>
> I've been in this business long enough to know there are always
multiple
> ways to get something done. I've got a lot of time invested in code
> that creates both schema and xml for my data, and really don't want
to
> throw that time and effort away.
>
> Your suggestion earlier of having a piece of code running on a
desktop
> external to Basex to provide the communication link probably would
work,
> but it is starting to look kind of like a kluge now, I think.
>
> The scenario.
>
> Desktop code accepts the connection from the mainframe, and
> connects to the Basex server.
>
> Would have to do a poll of Basex to determine if a new request
had
> been added to a request database.
>
> User, at a browser, would add a request to the database, and
then
> wait for the response.
>
> Code doing the poll would get the request and stuff it down the
> pipe to the mainframe, then go back to its poll. Needs to be able to
> recognize when data comes in on the connection as well.
>
> Response comes in, and the Basex request database is updated.
>
> Basex server sends the response to the browser.
>
> Would this work?
>
>
> On 10/19/2017 3:08 PM, Kendall Shaw wrote:
> > It does: HTTP.
> >
> > On 10/19/17, 12:42 PM, "basex-talk-boun...@mailman.uni-konstanz.de
on behalf of Dave Day" <basex-talk-boun...@mailman.uni-konstanz.de on behalf of
david....@duke-software.com> wrote:
> >
> > Unless websockets has some protocol sitting on top of
standard TCP/IP
> > communication, there shouldn't be an issue.
> >
> >
> >
> > On 10/19/2017 2:29 PM, Kendall Shaw wrote:
> > > On 10/19/17, 10:54 AM, "Christian Grün"
<christian.gr...@gmail.com> wrote:
> > >
> > > @Kendall:
> > >
> > > > If I understood, it was connecting from mainframe to
the BaseX server over a socket that was wanted (I assume that means TCP). I
think that websockets don’t connect to TCP sockets, without HTTP on both sides
to establish the connection. So, if using HTTP would require implementing HTTP
(or parts of it) in assembly language, that is not trivial, possibly.
> > >
> > > Yes, exactly.
> > >
> > >
> > > @Marco:
> > >
> > > > not only browser clients but all other application
(written in Java, nodeJS, Python ...) supporting websocket client libraries I
suppose! ;-)
> > >
> > > Quite definitely! I’ll knock at your door once the
first beta versions
> > > will be around. If you believe you can give some
helpful input on the
> > > feature design in the GitHub issue, your feedback will
be welcome.
> > >
> > > Great, in general. But, if one side is on the mainframe
unless there is a websocket library there the problem would be the same.
> > >
> > > Kendall
> > >
> > > > On 10/19/17, 10:15 AM,
"basex-talk-boun...@mailman.uni-konstanz.de on behalf of Marco Lettere"
<basex-talk-boun...@mailman.uni-konstanz.de on behalf of m.lett...@gmail.com>
wrote:
> > > >
> > > > Hi,
> > > > not only browser clients but all other
application (written in Java,
> > > > nodeJS, Python ...) supporting websocket client
libraries I suppose! ;-)
> > > > Waiting eagerly for it ...
> > > > M.
> > > >
> > > > On 19/10/2017 19:08, Christian Grün wrote:
> > > > > Hi Dave,
> > > > >
> > > > > Kendall has already given you all relevant
information (thanks!).
> > > > >
> > > > > Very early client bindings of BaseX provided
support for bidirectional
> > > > > connections. As the functionality was rarely
used, and as only a few
> > > > > bindings supported this part of the protocol,
it was eventually
> > > > > dropped. If you scan the history of our Wiki
and the Github sources,
> > > > > you will probably stumble upon the code
snippets.
> > > > >
> > > > > The major reason is that most of today’s
applications that are
> > > > > interactive and are built on top of BaseX rely
on HTTP. As soon as
> > > > > WebSockets will be available [1], it will be
possible to send data to
> > > > > browser clients.
> > > > >
> > > > > Hope this helps,
> > > > > Christian
> > > > >
> > > > > [1]
https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_BaseXdb_basex_issues_1449&d=DwIDaQ&c=DS6PUFBBr_KiLo7Sjt3ljp5jaW5k2i9ijVXllEdOozc&r=JgwnBEpN1c-DDmq-Up2QMq9rrGyfWK0KtSpT7dxRglA&m=HTzHEkqTVFJxI8dfoxQV2nh-Sx_PWJdIVZl7i7EiaAM&s=EE2LEkklhkn_5oQHObR67dH0aMbWgLwEP9Zcx5JHmYM&e=
> > > > >
> > > > >
> > > > >
> > > > > On Thu, Oct 19, 2017 at 7:01 PM, Dave Day
<david....@duke-software.com> wrote:
> > > > >> Hi Kendall,
> > > > >>
> > > > >> Thanks for the response.
> > > > >>
> > > > >> Seems to me there ought to be some way
to get a Basex server to write a
> > > > >> data stream to a socket other than as the
result of running a query or a
> > > > >> command.
> > > > >>
> > > > >> Maybe someone from the Basex developers
group will chime in here.
> > > > >>
> > > > >> -- Dave
> > > > >>
> > > > >>
> > > > >>
> > > > >> On 10/18/2017 7:56 PM, Kendall Shaw wrote:
> > > > >>> Someone can probably give a better answer.
As far as I know there are no
> > > > >>> xquery socket io functions provided with
basex. You can write java to do
> > > > >>> that or you can use an external process that
communicates with the mainframe
> > > > >>> and invoke that process from xquery, among
other solutions. If you write
> > > > >>> java you could look at the basex source to
imitate how it uses sockets
> > > > >>> and/or read about socket io in java. With
that you could poll or send and
> > > > >>> receive data to from the mainframe.
> > > > >>>
> > > > >>> To know if the mainframe connection is
connected, I think you can use the
> > > > >>> admin:sessions() function to see if it is
connected or your program that
> > > > >>> does the io could indicate that it is not
connected if it can’t communicate.
> > > > >>>
> > > > >>> If you use xquery and RESTXQ to write the
web application, and the same
> > > > >>> basex instance is communicating with the
mainframe then the xquery in your
> > > > >>> application is already running in the basex
server.
> > > > >>>
> > > > >>> For the second task it’s the same idea. You
will need to read about how
> > > > >>> updating works:
> > > > >>>
> > > > >>>
https://urldefense.proofpoint.com/v2/url?u=http-3A__docs.basex.org_wiki_XQuery-5FUpdate&d=DwIDaQ&c=DS6PUFBBr_KiLo7Sjt3ljp5jaW5k2i9ijVXllEdOozc&r=JgwnBEpN1c-DDmq-Up2QMq9rrGyfWK0KtSpT7dxRglA&m=HTzHEkqTVFJxI8dfoxQV2nh-Sx_PWJdIVZl7i7EiaAM&s=_pSKI0JdH9q6EQwFZt5180gq24TDNk9RHCCCU9529v4&e=
> > > > >>>
> > > > >>> Or, reading this would tell you a lot:
> > > > >>>
> > > > >>>
https://urldefense.proofpoint.com/v2/url?u=http-3A__docs.basex.org_wiki_Table-5Fof-5FContents&d=DwIDaQ&c=DS6PUFBBr_KiLo7Sjt3ljp5jaW5k2i9ijVXllEdOozc&r=JgwnBEpN1c-DDmq-Up2QMq9rrGyfWK0KtSpT7dxRglA&m=HTzHEkqTVFJxI8dfoxQV2nh-Sx_PWJdIVZl7i7EiaAM&s=d1UB9tyc9LKqvqvzoP9KPWE9x9Q2Va9Ge5qSYrTsEvA&e=
> > > > >>>
> > > > >>> Kendall
> > > > >>>
> > > > >>> On 10/18/17, 3:22 PM,
"basex-talk-boun...@mailman.uni-konstanz.de on
> > > > >>> behalf of Dave Day"
<basex-talk-boun...@mailman.uni-konstanz.de on behalf of
> > > > >>> david....@duke-software.com> wrote:
> > > > >>>
> > > > >>> Greetings list,
> > > > >>> I have an idea of how I want
to use Basex, and would like
> > > > >>> to know
> > > > >>> if what I am wanting to do will work.
> > > > >>> My background is IBM
mainframe, so the terminology I use is
> > > > >>> influenced by that.
> > > > >>> I have a server running in
an address space on a mainframe.
> > > > >>> Within
> > > > >>> that address space are multiple tasks
active. I believe the term
> > > > >>> task
> > > > >>> is equivalent to a thread in the
distributed world.
> > > > >>> I would like to have a task
initialize when my server comes
> > > > >>> up and
> > > > >>> establish a connection to an instance
of a Basex server. This task
> > > > >>> would
> > > > >>> be responsible for processing requests
that come in from the Basex
> > > > >>> server.
> > > > >>> On a browser, I want to have
a user connect to an instance
> > > > >>> of the
> > > > >>> Basex HTTP server. From the manual,
it states that if the HTTP
> > > > >>> server
> > > > >>> is started, the client server is
started as well. I don't know if
> > > > >>> this
> > > > >>> is all one instance of a Basex, or if
there are actually two
> > > > >>> processes
> > > > >>> that get established. The HTTP
server will need to know if the
> > > > >>> connection has been established
between the mainframe and the client
> > > > >>> server. Is this possible, and if so,
how would that be accomplished?
> > > > >>> Assuming that the user on
the browser needs some
> > > > >>> information from
> > > > >>> my mainframe server, is there a
mechanism in place to facilitate the
> > > > >>> HTTP server sending the request to the
client server, and the client
> > > > >>> server sending the request to the
mainframe. Would the mainframe
> > > > >>> have
> > > > >>> to do a poll of some kind to see if
there was data, or can the client
> > > > >>> server push the request out across the
connection?
> > > > >>> If the above works, that is,
Basex acting as a message
> > > > >>> broker
> > > > >>> between a browser and the mainframe, I
want to be able to create
> > > > >>> another
> > > > >>> connection from another task on the
mainframe to the Basex client
> > > > >>> server
> > > > >>> as a result of a user request on a
browser, have that 2nd task create
> > > > >>> a
> > > > >>> new database, and start pushing xml
across that 2nd connection.
> > > > >>> While
> > > > >>> that new database is being updated
from the mainframe, can the user
> > > > >>> on
> > > > >>> the browser query the new database to
get the most current data?
> > > > >>> Regards,
> > > > >>> -- Dave Day
> > > > >>>
> > > > >>
> > > >
> > > >
> > > >
> > >
> > >
> >
> >
> >
>
>
>
