Thanks for the explanation, except I'm still not clear what a
"connection name" is. See below for my 2 cents.
Grzegorz Kossakowski wrote:
The only problem is that we have no way to check if given URI contains
connection name or servlet
ID. Therefore the idea to add special sign that would remove the ambiguousness
appeared. Current
proposal are:
a) add a plus sign after servlet ID (by Reinhard)
b) add a exclamation mark at the very beginning of the path (by Vadim)
My personal preference is a plus sign but as Reinhard already pointed out it
does not matter that
much because we usually won't be using absolute URIs directly.
Yuck, yuck, yuck. (If you get the impression I don't like a or b you
are on track).
c) Use a different scheme to identify one vs the other.
d) Use a different pattern. i.e "conventional" urls look like
http://authority/path where authority can be a variety of things such as
"server[:port]", "[EMAIL PROTECTED]:port]" and server can be a domain name or
an ip address. In this case, you could do something like
servlet://[EMAIL PROTECTED]/path which, if I understood you correctly.
could be abbreviated to servlet://connection/path. For servlet id you
could use the same syntax with servlet://[EMAIL PROTECTED]/path. Of
course, since I don't really know what a connection is I have no idea if
this makes sense, but it could certainly be abbreviated to
servlet://@servlet_id/path. Or use servlet://[connection][:id]/path,
although servlet://:Servlet_C/path still looks a little odd.
+ and : characters in uri's just plain look strange, even if they are
allowed, unless they are used in a similar fashion to existing schemes.
Also, not having the // in the uri makes one wonder just what the token
before the first slash is. Everybody knows that whatever follows the
double slashes is not part of the path so it is less confusing.
-- o0o --
Now it's the time to give some description of static connection list problem.
Currently one can
define list of connection of a given servlet statically in XML config. If you
compile a block there
is no chance to add new connections to other servlets. Now, imagine situation
that you have some
application making charts and you create separate block (and servlet) for each
datasource provider.
For example, you create block that extracts some data from database and second
one that extracts
some data from mailbox. If you want to pull this data, you need to connect to
these two blocks of
course so you add them to your local connection list.
Now you can compile your application and everything will be working fine. But
what if you want to
define another datasource for your charts, for example data from some web
service? Of course you
develop a new block that downloads and transforms interesting data but you need
a way to inform your
appliction that there is a third block. The most obvious way is to add
connection to the third block
but this involves recompilation of your application!
The solution that I and Reinhard (and probably others) have in mind is to let
servlet use absolute
URIs so you don't need to define connections statically to other block. There
would be also some
discovery mechanism of available blocks, probably a generator, that would
return you a list of
blocks fulfilling particular needs. The list would contain servlet ID of each
servlet (block) so you
could reference them later on.
I hope this helps you a little bit.
I still don't quite get this connection thing.
What I don't get is why this can't just be servlet://[EMAIL PROTECTED]/path?
Or better yet, why shouldn't my application just reference a bean id and
wire it to the block service in its Spring configuration (think Spring
remoting)?
Please reply, even though I'll be on a plane in a few hours. I'm sure
I'll find time to look at email while I'm out of town.
Ralph
