#django

cfoch: very simple real world example: https://github.com/tBaxter/tango-contact-manage...

I have a CharField as my primary_key, and its intent is to act like a UID.

This UID is built from data in other fields on the model instance though.

Hi, I have a named url that I can access with {% url 'name %}, but how can I access this within python, in a function?

A primary key for a VideoFile might be "filename.jpg h3rc1h4" for example, with filename.jpg being the value in some other CharField on the model, and the random characters represent the first 7 or so chars from an MD5 field.

One of the fields on this model is a ManyToMany to 'self' ; the problem I'm facing is generating a unique UID value when I want to use the add method: video_file.parents.add(new_video)

desmond: look up reverse()

kizzo, I can't help you, but I do think you're making the PK way harder than it has to be. Or should be.

Maybe I am. I think my goal is to make something like a natural composite key.

I think maybe I talked about this problem before, and I'm coming to the same conclusions now ha.

Just sounds like a lot of aggravation, and I'm not seeing the advantage

My real concern is how beautiful/nice the data looks when in json format - I don't want the primary keys to be integers.

what difference does it make, really?

I suppose I'd probably output my json myself if I was feeling super-particular about it.

Hi!

I want to be able to uniquely refer to model instances via an arbitrary selection of model field values, I think.

My csfrmiddlewaretoken and my csfrtoken cookie have different values. why?

Yeah they say the same thing in the docs: https://docs.djangoproject.com/en/1.6/topics/se...

It just looks bad in the fixture, and for later too, when you want to refer to the same model instance, I don't want to have to use an integer.

So I'm like, ok, change the primary_key to a CharField, and then specify a UID-generating algorithm that makes use of theh available info in other fields, to create this field.

kizzo: I think you should re-read the docs you just linked to. Looks to me like they give you your answer, without jacking with the PK, using use_natural_key

If I'm reading it right

Yeah ok that's for a different task, but I understand, yeah.

Let me find this other thing..

Dealing with this issue, combined with ManyToManyFields, is the problem I think:

That doc explicitly says that you can't associate until the instance is saved.

I have overridden the save method on my Model with just this:

self.compute_uid(*args, **kwargs)

super(FileDisk, self).save(*args, **kwargs)

And the job of self.compute_uid() is to set the self.uid attribute/field on the model.

filedisk:filename='file.jpg',md5=blah

Yeah mabye you're right.

I'll stop trying, and see if I can get away with it.

kizzo: take a look at those docs again. I think you need to leave PK alone and use the natural keys stuff. I've never used it, but it looks like it's made just for what you want to do

Yeah. When the database is running, and your site is up, code is running, things are live, the plain integer pk is fine, and the Model.objects.get() method's keyword arguments satisfy the need for looking up things uniquely, enough.

And when exporting to json, yes the Django parts do that for you.

So I think things are cool.

I have MyModelDetailView. It shows as a table. The only problem is that ManyToManyFields aren't displayed. I would like to display them as <ul>. How can I do that?

cfoch: just follow the relation

Tip: look at the admin docs. They'll show all your relations in your models and how to follow them.

I am writing a option to update a database record(that already exists). I will be using a form to populate the preexisting data. I am using class bassed views. Will UpdateView automatically populate the form with the data or do I need to pass that database instance to the form when I do form_class = ModifyForm?

https://docs.djangoproject.com/en/1.5/ref/contr... I'm following this example for site maps, and I have a working site map for my model. How do you include your homepage in the site map? (or is that not necessary)

HowardwLo: it's not really necessary. If you really want to do it, it's probably easiest to just build a second sitemap file with your index pages

dman777: a simple updateView will do it all for you.

in about three lines

also, don't name your form ModifyForm

Actually, you probably shouldn't have a "modifyForm". You can probably use the same form for creation and updating

tbaxter: thanks. Is ModifyForm a reserverd word? Just curious

No, it's just a lousy name. What happens when you write your second app?

true...good point

I don't know what your model is, but generally, you'd want "ModelnameForm" and you could use the same one for both creating and updating

tbaxter: my index pages don't have models and aren't flat pages (i think). i made a view to serve each template.

right… that's mot unusual. At best, they'd be listviews and the sitemaps framework still wouldn't be very useful. That's why if you really want one, roll your own.

Just use a TemplateView and start outputting urls and stuff. It's not that different than building site nav

I've been having trouble with a NoReverseMatch error for some of my URLs when using the 'url' tag and the 'reverse' function. In trying to debug I've noticed that the reverse_dict being created from my URL patterns appears to have some spurious values that lead to the exception in question being thrown, but I haven't been able to figure out why the erroneous values are there. My URL Conf is https://dpaste.de/Rfhq. Forward resolution

the URLs all work properly. The issues with reverse can be seen in this shell transcript (https://dpaste.de/MOgg), as can the contents of the relevant entries in reverse_dict.

Any help would be appreciated.