#django

I think I just found a report generation trigger.... that uses GET

morning

morning!

I'm creating an admin interface and I'd like to have it so in the admin interface the value for a ManyToManyField is "related_field.__str__() - self.name" without actually changing the __str__() in the model. The rest of the m2m functionality is fine. Anyone know what to look for in the documentation? I couldn't see anything on the admin page's documentation that seemed to fit

morning!

morning

what's the best practice for a situation where I have a number of views that check if a valid instance of a model exists, and does thing A if it does and thing B if not?

Exception? return None and detect it as a sentinel? How do I avoid replicating that "try/except" in every single view?

doc|work: are you wanting to specify a different method other than __str__ to represent the related fields value?

(in this case, the view is dated: url /yyyy/mm/dd/ and either there's an instance of model A appropriate for that date, or there isn't)

joshbright, essentially, yes.

joshbright, at the moment I'm trying to override __str__ in the admin but I'm really not sure that's the best way to go

hackedhead: so, I use a django shortcut called get_object_or_404, which, either gets an object by its primary key, or, raises a 404 error

joshbright: similar idea, but I don't want to raise a 404

doc|work: it seems like you could do something with ModelAdmin to accomplish this, but, i havent had to do anything like that from what I can remember

yeah

hackedhead: in that instanced, I usually use a try / except thing where I check for django.model.DoesNotExist, something like that (id have to check again)

doc|work: The only admin-specific use of __str__ is on listing pages, and you can bypass that by specifying other fields (or methods) in list_display.

but, if you were to try to get an object from a django model, and, it doesn’t exist, it raises some sort of exception, so, you can check for that exception and just return false or wahtever

I have a quick question. I have a website with an editable table on it. The table is 6 x 6. I don't really need a database or anything like that, but I was trying to use django channels. My goal is to have real time updating editable table that is 6x6.... I was thinking about having a simple HTML/JS page open a websocket and fire off a "getall" request to get the current state.... then on each edit send a "edit x y value" json objec

subscribers.

Suggestions on how to do this?,... I was just going to store the table values in an array in python

EFaden: It's gotta be stored somewhere to be persistent after the Python process stops.

I don't need persistence.

joshbright: yeah, that's what I'm doing now, I just find myself writing the same try/except in several views, which seems like an antipattern

If it gets wiped out on reboot thats fine.

It wouldn't take a reboot. Worker processes are often recycled just as a matter of course.

hackedhead: so, you could write a util type of function that acts like get_object_or_404, but, acts more like, get_object_or_none

And of course if you had more than one process, then your state would vary based on which one handled the request.

EFaden: HTTP is stateless though, so the next time the client calls for an update, the original process from the earlier request is gone. you need persistence

so what do people do if a model's __str__ value isn't specific enough but they don't want to modify the model's __str__ to add the related data's __str__() which is otherwise always a bit redundant for the usual use

you pass it in the model and the pk, if it can’t find it, it returns none

?

Ah.... so what would be the easiest way to set tihs up then?

Setup a model for the table ?

joshbright: yeah, but then I'm just trading try/except for "if result is None:"... aren't i? is that better in any way?

hackedhead: well, with the get_object_or_404 function works well because, after getting that object, if your next line is ran, you have the object, you dont need to check for anything. if there wasn’t something there, a 404 was raised earlier and it doesn’t matter

so, you could look at how get_object_or_404 works, and raise something similar that bails you out of your function

doc|work: You can include related fields in list_display. As for things like form dropdowns, that label can also be customized so that it doesn't necessarily use __str__

i’d have to sorta see what your doing

mattmcc, yep, have done that. it's not so much for list_display but fields = (,)

how can it be modified? What should I look for in the docs? I still want to keep the manytomany functionality otherwise

Or I suppose what would be a simple setup for a model to hold a 6x6 table?....

doc|work: Check out label_from_instance https://docs.djangoproject.com/en/2.0/ref/forms...

mattmcc, thanks!

EFaden: A JSONField could hold a serialized array.

JSONField?

Postgres also supports arrays natively with ArrayField.

my admin site is not loading, it just loads my homepage. why?

urlpatterns = [

url(r'^', home, name="home"),

url(r'^admin/', admin.site.urls),

]

am i missing something?

the $

yep it was the $

thanks me

Yeah, '^' catches everything.

Hi guys, I’m trying to figure out how rest_framework.permissions.DjangoModelPermissions works in order to customize it to my requirements. Has anyone worked with it before?

theology: quack :)

lol

FunkyBob: the numbers of times I have said to my boss "Thanks for being a duck" hahaha

s/numbers/number/

could be awkward depending on your accent :P