Django admin site with mongodb - django

I am using django with mongodb through django-mongodb. I was able to set up the django admin site (through the fixes on the troubleshooting page), now when I use the admin site I am able to view all of the top-level fields, but (somewhat as expected) the embedded objects and lists are not able to be viewed, they just show up as a print would show them, "List Object" for example.
Is there any way to use the admin interface to view the sub-models etc...?
If there is no convenient third-party way, how would I go about supporting this behavior myself?
If there is no simple way to support this myself, is there a phpmyadmin type of thing for mongo that I can use in conjunction with django-mongodb (This could just be something that sits on top of mongodb not necessarily using python/django)?
*Note: I have been using the word 'view' in reference to my interaction with the model, my first preference is to be able to view and not edit, however if there is editing capability out there, that might be better, depending on how complex the modifications will be.

I have actually been doing the same project lately. The admin site doesnt really know how to represent the non-relational style elements that are present in a mongodb document, so you would have to define custom field/widgets. Refer to this part of the documentation which explains how to extend your ModelAdmin to specify overrides.
https://docs.djangoproject.com/en/1.3/ref/contrib/admin/#modeladmin-objects
For list types for instance, django has no way to know what type of values the list contains and how to represent them.
As for a visual mongodb manager, not sure what OS you are on, but Im on OSX and I love this one: http://mongohub.todayclose.com/
Otherwise, here is a list of other management options: http://www.mongodb.org/display/DOCS/Admin+UIs
Take your pick for either an OS native or web based.

Related

generate form fields from vocabulary (RDFS)

I have a vocabulary described with RDFS, consider for example the "Friend of a Friend" (FOAF).
Now I want to populate my database, so I want to insert the classes (the Person classes) and their relations (the friendship). I want to do that with a web page with the appropriate form field connected to a back-end server.
My ontology is more complicated than the FOAF (but it is based on it), so I am searching for a tool that automatically creates the web forms.
Presently I am not linked to a particular technology, but I would like to stay with RDF since I am also using rdflib, in particular for querying. Django seems to be a solution, but I am not sure how it interacts with RDF.

Single model for storing django application-wide options

I have a set of top-level configuration data fields that I want to be able to set within django admin for each deployment of my django app. I only want one set of these.
Example fields: site_logo, contact_person, address, facebook_url, twitter_url
The problem is that Django Admin is geared towards tables (lists) of models, so its not a good fit for this type of singular configuration model. I really only want one of these models to exist for the whole site, and to be able to click into it from admin and edit the various fields.
It seems i've come across a 3rd party app in the past to accomplish this but can't find it anywhere. Part of the problem is I'm finding it difficult to find the right words to google. Any ideas?
It looks like django-values will do what you're looking for.
Other possible contenders:
http://github.com/sciyoshi/django-dbsettings (doesn't look maintained)
http://github.com/jqb/django-settings
Have a look at django-livesettings it sounds like it might fit.
Not that i have used it, but i have heard good things about django-constance.
And there are even some more options listed in the Configuration-Grid on Django Packages.

Data structure for changing form using Django Models and Admin app

I am writing a Django application and using the built-in ORM. I would like to create functionality to provide a form but the template for that form needs to be built on admin side of the application and can change over time.
For instance, initially they have a form that asks for first name, last name but later if they decide to add birthday field admin should be able to go to this template page add birthrate as new field and on client side, users start seeing it. Is there anything already in place that can be used? I was thinking of using something like this but decided to check here and see if there is something better available.
Is it this what your are looking for?
I have never heard about any library for that, because you have pretty much different approaches to handle that!, but check the link, he is explaining better those approaches.

Avoiding circular dependencies in Django applications

While working on my Django-based projects I'm always trying to follow Django's approach to reusable apps - I'm trying to decouple my applications from each other and especially trying to avoid cross references but sometimes it does not seem to be possible.
Let's consider a simple example with 2 applications: articles and users. Articles application defines article model, articles list view and single article view, users application defines user model and user profile view. Article is referencing user from the author field, so articles application is obviously dependent on users application which is fine.
But when it comes to user profile, I want to display latest articles authored by the user (and may be latest articles viewed by the user) on that page but that makes users application aware of articles application which is what I'm trying to avoid.
I can obviously try to push all such references to the template level but it still does not solve the issue completely and at the same time may be very inefficient in terms of database queries sometimes.
What do you guys do in such cases?
If you are really set on not having any conversation between the 'user' app and the 'article' app, then you need a third app to act as interface. That would know about users and articles and define all the coupling between them. Your article view would be in there, since it has to get the user data, and your user profile view would be in there, because it needs to say "Fred wrote 5 articles".
Whether this level of decoupling is worth it, I don't know. Sometimes programming for re-usability gets in the way of making the thing usable in the first place.
The standard (or preferred) way of keeping coupled apps decoupled is to add a conditional coupling - like in some apps that try to import django-notification and only if they find it, they report events to it.
Still, if you have two apps that talks to each other by design, then I don't see any point in decoupling them - there are plenty of examples in Django world of apps that just require other apps. Note that I'm talking here about writing real-world software, not about some academic delibrations :-)
It seems that in this case, the dependency of users on articles is in a method, not a field. (Whether it's a model method, a model class method, or a manager method is immaterial). If that's so, you can do a lazy import of articles inside the method. By the time this import is performed, users.models will be fully loaded, so even if this is a circular import, it will not cause problems. The "import users" statement in articles will not have to re-load users and will have the full users namespace available.

Django: django-transmeta - sorting comments

I have created an article site, where articles are published in several languages. I am using transmeta (http://code.google.com/p/django-transmeta/) to support multiple languages in one model.
Also I am using generic comments framework, to make articles commentable. I wonder what will happen if the same article will be commented in one language and then in another. Looks like all comments will be displayed on both variants....
The question actually is:
Is there a possibility to display only comments submitted with current language of the article?
I tried the approach of transmeta for translation of dynamic texts and I had the following experience:
You want another language, you need to change the database model which is generally undesirable
You need every item in both languages, which is not flexible
You have problems linking with other objects (as you point out in your question)
If you take the way of transmeta you will need two solutions:
The transmeta solution for translating fields in a model
For objects connected to a model using transmeta you will need an additional field to determine the language, say CharField with "en", "de", "ru" etc.
These were major drawbacks that made me rethink the approach and switch to another solution: django.contrib.sites. Every model that needs internationalization inherits from a SiteModel:
class SiteModel(models.Model):
site = models.ForeignKey(Site)
Every object that would need transmeta translation is connected to a site. Every connected object can determine its language from the parent object's site attribute.
I basically ran the wikipedia approach and had a Site object for every language on a subdomain (en., de., ru.). For every site I started a server instance that had a custom settings file which would set the SITE_ID and the language of the site. I used django.contrib.sites.managers.CurrentSiteManagerto display only the items in the language of the current site. I also had a manager that would give you objects of every language. I constructed a model that connects objects of the same model from different languages denoting that they are semantically the same (think languages left column on wikipedia). The sites all use the same database and share the same untranslated User model, so users can switch between languages without any problem.
Advantages:
Your database schema doesn't need to change for additional languages
You are flexible: add languages easily, have objects in one language only etc.
Works with (generic) foreign keys, they connect to an object and know what language it is. You can display the comments of an object and they will be in one language. This solves your problem.
Disadvantages:
It's a greater deal to setup: you need a django server instance for every site and some more glue code
If you need e.g an article in different languages, you need another model to connect them
You may not need the django Site model and could implement something that does the same without the need of multiple django server instances.
I don't know what you are trying to build and what I described might not fit to your case, but it worked out perfectly for my project (internationalized community platform built upon pinax: http://www.bpmn-community.org/ ). So if you disclose some more about your project, I might be able to advise an approach.
To finally answer your question: No, the generic comments will not work out of the box with transmeta. As you realised you will have to display comments in both languages for the article that is displayed in one language. Or you will have to hack into the comments and change the model and do other dirty stuff (not recommended). The approach I described works with comments and any other pluggable app.
To answer your questions:
Two Django instances can share one database, no problem there.
If you don't want two Django instances, but one, you will have to do the following: A middleware checks the incoming request, extracts desired language from URL (en.example.com or example.com/en/ etc.) and saves the language preference in the request object. The view will have to take the request object with the language and take care of the filtering of objects accordingly. Since there is no dedicated server for the language (like in the sites approach where the language is stored in the settings.py file), you can only get the language from the request and you will have to pass attributes from the request object to Model managers to filter objects.
You could try to fake a global language state in the django application with an approach like threadlocals middleware, however I don't know if this plays out nicely with django I18N engine (which is also does some thread magic).
If you want to go big with your site in multiple languages, I recommend going for the sites-approach.