[DB-SIG] Re: [Python-Dev] database APIs

[Luke Kenneth Casson Leighton]

On Mon, Feb 03, 2003 at 11:35:05PM +0100, Magnus Lycka wrote:
> At 16:31 2003-02-03 -0500, Kevin Jacobs wrote:
> >On Mon, 3 Feb 2003, Luke Kenneth Casson Leighton wrote:
> >>  my goal ultimately is to be able to write a file, maybe in
> >>  XML or other suitable text file format, that specifies all the
> >>  reports i want, that they are just tabular display of records,
> >>  generation of an input form, or generation of create / delete
> >>  input form.
> 
> What makes you think XML will be a better very high level programming
> language than Python? 

 see http://sf.net/projects/virgule and then tell me if you
 think that question _really_ needs asking of me!!!!!!

> Isn't that really what you are saying? 

 nope.

> And don't
> you think that special cases will pop up now and then that will be much
> easier to handle in Python than in XML?
 
 i believe i described, later in the email to which you replied,
 that it should be possible to over-ride special cases.

 SQLObject does this by checking for the existence of some
 functions in the over-riding class, where the name of the
 function to check for is _{column_name}_{update|del|set}()
 or something like that.

 for example in the display of certain fields in a table,
 in pysqldb i provide a means to pass in a function to
 perform the HTML rendering.

 if no such function is given on a per-column basis, then
 cgi.escape(str(value), 1) is used.


 the idea that i had was that the XML file should specify the
 module and the function name to be used to display the
 column.

 alternatively, the XML file specifies the class name (or a
 particular class name is expected by default based on other
 context e.g. the table name, report name etc) and if that
 class exists, and a function _in_ that class exists with the
 name display_in_html_format_{column_name}() then it is called
 to render the relevant field.


 the same technique may be used to specify the reporting format:
 the XML file specifies the type of the report by name, and
 a rendering module is expected to contain a function by that
 same report name, which does the actual work.


 ultimately i really don't care what is used.

 XML, HTML/templating, SQL databases, flat files or python.

 i just want simpler applications.


> I'm sure you are right about constructing something along what you
> are talking about, or using one of these available tools, but I still
> think Python scripts, using these more abstract tools, is the optimal
> tool do describe each form or report in.
> 
> What is it you can do in XML that you can't to in a structure of
> nested lists etc in Python? 

 you can't get python accepted by perl or php programmers or
 non-technical administrators.

 you _can_ get the pyxml libraries to read XML documents into
 structures of nested lists etc.

 you _can_ get XML accepted by other editing systems.

 win-win.

 [you can also get flat-file and SQL databases accepted by
  non-programmers]

 l.



 [@BEGIN IRRELEVANT XML STUFF

 hit delete, now, if you don't want to hear about XML...

> There are certainly a lot of things you
> can do in Python that you can't easilly do in XML...

 tell me about it.

 xvl/virgule is a non-NP-complete programming language with an
 XML-based-syntax.

 your comments here lead me to believe that you misunderstand
 what XML is, can, and cannot do.

 XML is nothing without meaning being provided.

 it's just a pretty data format.

 XML doesn't run, it doesn't execute, it doesn't sing or dance.

 for XML to have meaning, there must be three things:

 - the data.

 - the interpretation of the data.

 - a program to make use the interpreted data.

 if you do not have any one of those three things,
 XML is xxxxing useless.

 i recommended XML on the basis that it is becoming widely
 accepted as a data format.

 people often mistake it as magic :)

 @END IRRELEVANT XML STUFF]