On 03/20/2013 05:38 AM, Frank Millman wrote:
On 20/03/2013 10:56, Dave Angel wrote:
On 03/20/2013 01:58 AM, Frank Millman wrote:
On 19/03/2013 17:03, Dave Angel wrote:
<SNIP>
Dave, I really appreciate your input, but we are talking at cross
purposes somewhere along the line - I am not sure where.
Firstly, just to ensure there is no confusion, I am not talking about
*database* schemas, I am talking about *xml* schemas. From Wikipedia,
"An XML schema is a description of a type of XML document, typically
expressed in terms of constraints on the structure and content of
documents of that type, above and beyond the basic syntactical
constraints imposed by XML itself."
Let's focus on 'form definitions'. What I call a 'form' is something
that can be displayed on a user's screen, for data entry, data display,
or both, containing text, input fields, checkboxes, buttons, etc, etc. I
have devised an xml format to describe the form. When requested, the xml
file is read in and sent to the client, which extracts the elements and
renders them on the screen.
All form definitions are stored in the database. To ensure that they
conform to the standard structure which the client is expecting, I have
written an XML schema that can be used to validate the content.
The XML schema is stored in its sub-directory permanently. Once
debugged, it will never be altered. It is the equivalent of source code,
that is read and interpreted at execution time.
That paragraph says it all. It's constant, so it belongs with the
source code. Somehow I thought you were writing the xml into that
directory. Thanks for clarifying.
When a user selects a menu option, the form definition is read in from
the database, parsed and validated by lxml using the schema, and if ok
it will be sent to the client for rendering. Otherwise an exception will
be raised.
Hope this makes more sense.
Frank
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DaveA
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