Re: Some questions about file handling + some other things

On Wed, Mar 24, 2021 at 12:55:12AM +0100, Nagy Gabor wrote:
> One more question on Dates. The dates must be submitted in
> html form variables in the standard date format 2021-03-24.14:00,
> right? There are methods for printing dates in alternative format (like
> pretty()), but it seems to me that the date submitted to Roundup must
> be in this format. And I guess if my users want a different date format,
> then I have to do the conversions on my own.

You can also enter dates in the extended format that allows for
arithmetics on dates, e.g.

.
.+5w
.-3y

would all be valid dates to enter in the date field.

> And some additional comments I've run into this weekend:
> 
> The sorted method of Multilink properties (provided by the cgi engine),
> does not always work as expected. First, I got Python error on
> context.files.sorted('filetype'), when the 'files' list had an item
> with 'filetype' unset.

Sorting by Multilink happens in Python not in SQL. What is your use-case
for sorting by Multilink? In my experience the sort order created by
this is hardly understandable by humans.

I would like to deprecate its use.

> Second, this method does not seem to respect the data type of the
> 'order' property of 'filetype' class.

This is definitely worth a bug-report, especially if this also applies
to sorting by non-multilinks.
I *think* we currently allow only strings as key- order- and label
properties. This should probably change.

I also at one time wanted to implement key properties with multiple
values: An application often demands uniqueness over several properties
not just one. I discussed this *many* years ago with Richard but he
feared at the time that things would be complicated by this. I still
think it would be a useful feature.

> It was set to Integer in my
> schema.py for the 'filetype' class, but sorted() treated it as a string.
> It took a while until I realised that the reason for unexpected sorting
> is "12" < "2", for example. :)
Ouch :-)

> Finally, one more minor question. Assume that I want to sort notclosed
> tasks by 'deadline' in increasing order (which seems reasonable). In
> this case the first tasks will be those for which deadline is unset.

Yes, this happened more-or-less accidentally: It is the default order of
mysql and was correctly covered by the regression tests, so sorting them
in front is explicitly done in the generated sql for other backends.

> But what if I want to put them to the end of the list? How this can be
> done?

You currently cannot change the way things are sorted (Except for the
sort direction).

> (First try: I won't allow unset deadline, it is 9999-12-31 behind
> the scenes.

Yes, this is a sensible choice if your application allows it.
You can code an auditor that sets the date to some default value if the
user didn't supply one.

> Second try: I do two database query for tasks (the first
> one filters on 'deadline is set', and an other one filters on 'deadline
> is not set', and join these list.

Yes, this can be done in an explicit index template if you really need
that behavior.

> But this is just an example, I am more interested in how these
> filter/sort cgi request can be customized, or the obtained "batch
> list" modified?)

Currently you cannot customize how individual properties that are
included in sort and/or group are sorted, except for reverse/forward.

Ralf
-- 
Dr. Ralf Schlatterbeck                  Tel:   +43/2243/26465-16
Open Source Consulting                  www:   www.runtux.com
Reichergasse 131, A-3411 Weidling       email: [email protected]