Andrew Ho writes: > On Sun, 9 Nov 2003, David Forslund wrote: > ... > > Well sure, but when I make the call to the Zope object it replies in > > HTML. If it replied in some other way, my browser wouldn't no what to > > do with it. > > Dave, > Both statements above are not true: 1) Zope can send back any kind of > file. 2) Web browsers know what to do with many non-HTML files (e.g. plain > text, gif, jpg, etc). > 1) isn't what I said I said I invoked the object and that is what I observe it returns. How do I tell it to return something different? 2) deal with many file types, but I may need to know something about the type (which is wny there are things like MIME types) > > Where do I find out what Zope will answer with? > SO I write client code by probing a server and seeing what it answers with, rather than having a place where I can ask what it wants? One is much more efficient than the toher. > It is very interesting that you are so pre-occupied with having a second > channel for predicting/describing the server's response. Why not just send > the REQUEST to the server and see what RESPONSE comes? > > > The flexibility is great, but there needs to be some agreement between > > the client and server as to how they will express the request and > > response. That is my only point. > > I don't think there is any disagreement on this point. However, there are > many ways to document, negotiate, and transact according to this > "agreement". Perhaps CORBA and Java have a more elaborate and rigid way of > doing this - but that does not mean it is more suitable or more useful for > application development. I can write a CORBA client that completely configures itself based on the data types coming back. Not very "rigid". It can, in fact, discover the data type coming back rather than having to "guess". > > Zope applications also implement interface and request/response > descriptions. They are just not in the format that you consider > "legitimate" interface description language. For example, I showed an > HTML form as the "interface description" for adding a sub-folder into the > OIO Library. :-) > Is this a standard way that is available for any Zope object? > ... > > If I make a URI request to a Zope server, it may have no idea what I'm > > talking about unless we exchange some other semantic expression of the > > meaning of the URIs. > > Yes, indeed. > > What would you call this? > http://www.txoutcome.org/scripts/zope/library/files/browse/newfolder?syndicated=0&objectid=313&oio_library_language=english > I can't tell. > To me, it looks like the server telling the client the _semantics_ of the > arguments to be submitted to add a sub-folder. > > > That is why one has additional standards for understanding what the > > meaning of a request is. > > Explaining why some people enjoy defining additional standards for > "understanding the request" and "understanding the understanding of the > request" is topic for another discussion :-). > Perhaps, but that isn't what I'm talking about. > ... > > >HTTP requests and responses can be arbitrarily complex and large. > > > Certainly, but they are are simply name value pairs or name values list > > going in and arbitrary text coming back. Only a mime type can tell me > > what to do with the data coming back, > > That's not true. You can embed processing instructions (even Java code) in > the response. How do I know it is Java code? > > > and I can have no way of knowing what to send to a server, unless it > > sends me information on a previous call, which is basically how the web > > client/server relationship works. > > Right. That's why we have "previous calls". It does not matter whether we > are using CORBA, Java, Zope, PHP, or C, either the client acts on > assumptions or the server needs to send info to the client on the > [previous, same, or future] call. > Perhaps, but I don't need that to make a DNS or LDAP call. I understand the semantics and ack on them > ... > > I'm sure they are not, but what will my client (web browser) do with the > > information if I have no idea what the format is coming back? > > The server told you on a previous call? :-) > The server told you on the same call? :-) > The server will tell you on a future call? :-) > > > >However, reflection in HTML is not necessary and any reflection in the > > >user interface may be indirect and optional. For instance, data > > >representing multiple attributes of clinicians, supplies, procedures, > > >etc in a hospital can be downloaded as needed and used to inform > > >complex user interactions including browser-local database queries and > > >on-the-fly generation of popup lists and tables, etc. > > > All customized and non standard, of course. > > I disagree. HTML happens to be a nice standard that the Mozilla web > browser renders adequately. > But HTML doesn't tell me what any of these things "are".
> > I can use tcp/ip directly, too. So what is the point? > > HTML is a good starting point. Other XML-based standards (e.g. SVG) > extend what web-browsers and servers can easily communicate. These > text-based, tagged "languages" are incrementally delivering what CORBA > and Java hoped to achieve. > > At this point, it is more productive to consider why HTML/XML are more > popular. Study platforms that embody philosophy and approach that are > synergistic with HTML/XML (e.g. Zope). Bring those attributes to health > care/ medical applications! :-) > > ... > > > I can put anything into XML, but it doesn't mean that the person on the > > other end will have any idea what I'm talking about, > > That's where "standards" like HTML and SVG come into play. > > ... > > When I made a call on a Zope server it gave me an answer back in some form > > of HTML. > > That may be quite appropriate if you are requesting a web-form from a > web-browser. > > ... > > > A Zope server could talk to another Zope server without using HTML, but > > I still believe the resulting code would be nearly impenetrable because > > everything is called the same, and I would have to wade through the > > various arguments to tell what was being asked for. > > No, send anything you like - send an XML document between Zope servers. How do I know what the meaning of the terms in the XML are without having some external standard? Dave > > Best regards, > > Andrew > --- > Andrew P. Ho, M.D. > OIO: Open Infrastructure for Outcomes > www.TxOutcome.Org >
