#django

It seems to be source of your error. (you're executing query there?)

https://dpaste.de/WbMB. django-guardian assign_perm is not working according to docs.

unless assign_perm invalidates the user instance's perm cache, that's not a huge surprise.

kezabelle: I did not understand.

kezabelle: Also, instead of a foreign key from user to plant I have an m2m, does that make any difference?

I have the following hierarchy. Plant -> Site -> Unit -> Zone. A user can be associated with instances of any of the above. User has 4 m2m keys with each of them. But at one time he can be associated with instances of only one of the models. Now I need to return instances related to the user. How do I do it?

I also need to return the children of the instances the user is related to, so it user is related to plant1 and plant1 is a foreign key to site1, site2, site3. I need to return all of those.

in jquery i have this --- > var action = $('#'+i+'-action').text(); which prints "OK" in the console but when I do if action=="OK"" doesnt come true

sydbarret: Are you sure that is exacgtly "OK" that there are no whitespaces anywhere?

let me paste you in fiddle

here https://jsfiddle.net/uhgsedxt/33/

it should print "you can only revert negatives" when the a_action column is "OK"

sydbarret: But your a_action value in column not "OK"

<td id="form-1-action"> OK</td> <-- See, you do have a space there. " OK" is not the same as "OK". Of course.

you are right

sydbarret: https://developer.mozilla.org/en-US/docs/Learn/...

how to fix in those cases? because that was inserted like that in th model innit?

And well I guess you have to figure out the fix yourself...

have you used that crispy in forms?

i have a formset that is rendered without spaces

I don't use any crispy in my forms.

what do you use for tabular data, just css or bootstrap?

I have the following hierarchy. Plant -> Site -> Unit -> Zone. A user

can be associated with instances of any of the above. User has 4 m2m

keys with each of them. But at one time he can be associated with

instances of only one of the models. Now I need to return instances

related to the user. How do I do it? I also need to return the children of the instances the user is related to, so it user is related to plant1 and plant1 is a foreign

key to site1, site2, site3. I need to return all of those.

Apologies, It turned out bad

Does anyone have a response for my query?

some attribute of my model are slow to calculate but depend on others model/table ... how can I cache the result up to when the row on the table on which he depend change?

berto_: Caching is easy... cache invalidation is really hard thing to do...

jtiai, how people generly proced on this kind of problem ... when you have a attribute or your module which are not field on the db table and are slow to compute? Any reference on what should I look ?

berto_: as always... it depends

you can used, for instance, cached_property so it's only calculated once per instance [from django.utils.functional]

FunkyBob, I used cached_property but does not seam to make a great difference .... if I do twice a get request on the same model it seam have the same time reponse

I have a hierarchy as following. Plant -> Site -> Unit -> Zone. A user have m2m fields with each of them but can be assigned to instances of only one model at a time (Head of Department). I need to get all the instances under the user. I also need the child instances (for instances the current instance is foreign key to). I am using this logic currently: https://dpaste.de/E1o9

FunkyBob, I actually calculated more attentivly and even if is still very slow ... the reponse is more fast

so chacted_property helped

is it possible to access M2M table (one that has been automatically created), with ORM ?

or the only way is to specify a `through` model ?

dodobas: yes, it is possible. something like `.through`

moldy: oh, nice, tnx

don't remember exactly right now

Model.m2m_field.through

:)

Any response for my query?

usr123: what is the problem? too slow?

moldy: I need to return instances related to the user and the instances which have the above instances as a foreign key.

My hierarchy is as such : Plant -> Site -> Unit -> Zone. Each has a m2m field with user.

So if user(head of department) is a Plant level user, I need to return all the plants related to that user and all the sites related to all these plants.

usr123: you showed us your current code, but you did not tell us what the problem with the code is

usr123: anyway, maybe something like this: https://dpaste.de/YZ0s

moldy: Yeah, It's kind of hectic to construct querysets like that. And I may have other cases coming up. So I wanted to know what is the standard way of dealing with user-instance relationships

"hectic"?

there is no standard, since use-cases are different. many projects just work with a plain FK or M2M, but your case seems to be more complex

moldy: So I have 4 levels and HOD can be assigned to anyone of these level's instances. I would not know in advance, but I have this info stored in HOD.level. Because I can't know what models to query, I need to write generic code. But like this I would have to construct querysets for each need. I wanted to know if there is a standard library which handles these relationships.

new to django. is it possible to extend app model with another app? I want to add field to existing app (add https://github.com/callowayproject/django-categ... field to https://github.com/aldryn/aldryn-events). should I create new app in which I will subclass model, and install both? or new app which will include everything from base app?

moldy: Was looking at django-guardian, and they have a way to return all the objects related to user, but it does not work for some reason

So Im using django-import-export in my admin area. When importing, I get a lot of errors because of violating not-null constraints.

When I am in the admin form however, I can save (without putting values in the field)

usr123: i would solve a specific case first and then generalize it

So I guess the only way to solve is by using null=True on the model fields?

moldy: Ok, Thanks. And thanks for the code as well. I didn't know I could do plant__in

usr123: there is nothing wrong with a few ifs / elifs here. KISS.

if HOD.level == 'plant': # query plant models. elif HOD.level == 'site': query site models

fub: no

fub: in general, don't change your models just to make some utility package happy

fub: if having null=False on those models makes sense from a data modelling point of view, then stick with it. adjust your import / export code to pass proper values when saving.

btw, django-import-export is nice for simple cases, but if your import is highly customized, i recommend to just roll your own thing

moldy: yeah I figured out I need to write my own import because I fighting already with it for some things

moldy: where can using null=True be a problem?

you can also customize django-import-export, it supports custom fields and such

moldy: Yeah, that would be the perfect way to do it. But this software is client specific, and client keeps changing so I wanted to write something so that even if new models get added and foreign key relationships change, the code still works

but at some point, it becomes easier to write your own thing. i am currently working on a 1k lines import module based on django-import-export. i wish i had just written my own ;)

moldy: But yeah, ifs and elifs would be much cleaner compared to this.

fub: whenever something should not be empty / NULL in the database

usr123: models are static. when a new model is added, you are already changing your code.

moldy: Ok, thanks for the advice, I should KISS

moldy: the fields in question are only text fields, so I dont think it can be a problem here, right?