Re: [Fwd: Re: Pregunta sobre el estado de gnome-db para el desarrollo]

[Vivien Malerba <malerba linuxave net>]

On mar, 13 jun 2000, you wrote:
> Well, I think that glade/libglade should only be used for the UI
> presentation. But apart from this, you need a file format to store the
> report itself (not the UI stuff, because the UI stuff is built
> dynamically from the report file format). This file should be something
> like this (with thousand more things):
> 
> <REPORT>
> <DSN>
>   <NAME>test-dsn</NAME>
>   <USER>username</USER>
> </DSN>
> <DETAIL>
>   <SQL>SELECT name, address, email FROM agenda</SQL>
>   <FUNCTION>function to be called for each row</FUNCTION>
> </DETAIL>
> </REPORT>
> 
> (This is just an example, so don't get it as the 'real' format)

The XmlQuery stuff is designed to have a convenient way to store queries in a
file (rather than using SQL-like specific text for each query). So the usage of
XML for the report part is to help you store (and read) a report (rather than
storing it in a binary or very specific way). The XML language allows you to
structurate the data you want to store. That structure is described in a DTD.
For more info on XML, have a look at:
http://www.w3.org/XML/1999/XML-in-10-points
http://zvon.vscht.cz/ZvonHTML/Zvon/zvonTutorials_en.html
http://www.oasis-open.org/cover/
http://www.w3.org/TR/1998/REC-xml-19980210
http://rpmfind.net/veillard/XML/libxml.html
So, you should first list ALL the functionnalities of a report, then describe
what the structure of the XML file should have (you can do it with a DTD, but
it is not necessary).

Once this is done, you should create a lib that allows one to use your XML file
format (with functions like gda_report_save. gda_report_add_detail,
gda_report_set_title,... whatever you think can be usefull and hide the dirt of
the XML format from the person using your lib).

Then, write a GTK widget as Rodrigo described below.

> 
> Then, as I said in the other mail, you write a wrapper to manage this
> file format (gda_report_save. gda_report_add_detail.....). And then, you
> write a GTK widget which lets you visually design and execute (preview,
> etc) this file format.
> 
> All these are just ideas, and are, more or less, what we talked with
> Cédric (am I right Vivien? Cédric?)

Yes!

> 
> And now that I think, I don't know if using libglade is the right thing,
> because we don't want to have a static format stored in a file, but a
> widget capable of converting the report file format into a visual
> representation of the report structure (not the report itself!) as, for
> instance, the Crystal Reports designer (I don't remember the name, but
> it's the part where you design the report) does. Then, this widget must
> also be able to print (and preview) the output of the report, but this
> is dynamic, not a file which is loaded. And if you want to save the
> report output, gnome-print DOES include support for doing so.

I also think that it's up to the widget you will write to take whatever
presentation structure is mentionned in the XML file, and produce something
which can be displayed, then printed, etc. So I think that your XML structure
should allow the inclusion of presentation directives (such as column fonts and
size, titles, etc).

Have a look at a soft, Metaphrast, that I found some time ago at:
http://www.mutinybaysoftware.com/metaphrast.html
I think they are trying to do something similar.

> 
> But again, correct me if I'm wrong!
> 

Regards,

Vivien