Re: Form/view for ManyToMany relationship
Le 05/03/2011 00:01, kgardenia42 a écrit : Thanks. This is pretty close to what I'm doing. However, I'd like to not have to write all the associated boiler-plate (i.e. I have to figure out if any film/actor relationships have been deleted since the last save and explicitly write code to remove those and so on). Well, you can delete all related filmrole then save the new set, but I don't know if it's really an "efficient" way to handle that. Out of topic: I have an obsession about providing "undo" ability as much as possible and showing changes before "committing" may help user too. It seems that I would even have this problem if I added a simple "auto now" date/time field to my relationship class, which seems a bit restrictive. Using a "timestamp" allows you to never edit / delete a entry: you just add new ones and work on last "timestamped" related entries for current data. I use this myself intensively because I _need_ to provide audit tables. I use in this case two apps: one "normal" (without timestamps) and an "audit" app that is dependant of the "normal" app. I use two distinct tables (databases, actually) and performances are ok in my context (including about 30,000 modifications by batch at once at least once a week). ModelForm already knows how to do all that (it can do so when the relationship class is implicitly created) so what I imagined was *somewhere* I could override a method and provide the defaults for the missing fields and then it would all just works magically.Does this make sense? Can anyone give me any pointers to how I might do this (I'm keen to learn the "right way" to do things). You can provide defaults in your Model. (I don't know if it's really required, but can use constants in these case: this allows to retrieve these entries without introducing more hardcoded values in your code) I'm happy to hack this myself and contribute something if someone could give me some pointers of where I should start or where something like this ought to live. I don't feel comfortable with your way to handle this relashionship, but it may be appropriate in a "wizard" approach. Maybe some form related project can appreciate your efforts. Regards, -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
Re: Form/view for ManyToMany relationship
On Fri, Mar 4, 2011 at 1:08 PM, werefr0g wrote: > On Thu, Mar 3, 2011 at 11:50 AM, werefr0g wrote: > > Hello, > > Sorry if I misunderstand, but what is wrong about using a ModelForm on your > Film bounded to the film instance? > > My bad... how did I missed the intermediary model involved in the ManyToMany > relashionship. Sorry. > > When I tried that I kept running into this error: > "Cannot set values on a ManyToManyField which specifies an > intermediary model. Use foo.FilmRole's Manager instead. > > As you are using an intermediary model, you must insert multiple FilmRole, > one for each actor to this film, but you don't want using a formset, do > you?. > > Is the following going toward your goal? > > # forms.py > class FilmActorsForm(forms.Form): > actors = forms.ModelMultipleChoiceField(queryset=Actors..., > required=...) > > # views.py > def assign_actors(film_id): > film = get_object_or_404(Film, id=film_id) > if request.method == 'POST': > form = FilmActorsForm(request.POST) > if form.is_valid(): > chosen_actors = form.cleaned_data['actors'] > current_actors = film.actors.all() > # handle deletion / creation of filmroles > return HttpResponseRedirect(...) > else: > form = FilmActorForm() Thanks. This is pretty close to what I'm doing. However, I'd like to not have to write all the associated boiler-plate (i.e. I have to figure out if any film/actor relationships have been deleted since the last save and explicitly write code to remove those and so on). It seems that I would even have this problem if I added a simple "auto now" date/time field to my relationship class, which seems a bit restrictive. ModelForm already knows how to do all that (it can do so when the relationship class is implicitly created) so what I imagined was *somewhere* I could override a method and provide the defaults for the missing fields and then it would all just works magically.Does this make sense? Can anyone give me any pointers to how I might do this (I'm keen to learn the "right way" to do things). I'm happy to hack this myself and contribute something if someone could give me some pointers of where I should start or where something like this ought to live. Thanks. -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
Re: Form/view for ManyToMany relationship
sorry, I failed to pass the request to the view's function,.. Le 04/03/2011 22:08, werefr0g a écrit : On Thu, Mar 3, 2011 at 11:50 AM, werefr0g wrote: Hello, Sorry if I misunderstand, but what is wrong about using a ModelForm on your Film bounded to the film instance? My bad... how did I missed the intermediary model involved in the ManyToMany relashionship. Sorry. When I tried that I kept running into this error: "Cannot set values on a ManyToManyField which specifies an intermediary model. Use foo.FilmRole's Manager instead. As you are using an intermediary model, you must insert multiple FilmRole, one for each actor to this film, but you don't want using a formset, do you?. Is the following going toward your goal? # forms.py class FilmActorsForm(forms.Form): actors = forms.ModelMultipleChoiceField(queryset=Actors..., required=...) # views.py def assign_actors(film_id): film = get_object_or_404(Film, id=film_id) if request.method == 'POST': form = FilmActorsForm(request.POST) if form.is_valid(): chosen_actors = form.cleaned_data['actors'] current_actors = film.actors.all() # handle deletion / creation of filmroles return HttpResponseRedirect(...) else: form = FilmActorForm() Regards, -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en. -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
Re: Form/view for ManyToMany relationship
On Thu, Mar 3, 2011 at 11:50 AM, werefr0g wrote: Hello, Sorry if I misunderstand, but what is wrong about using a ModelForm on your Film bounded to the film instance? My bad... how did I missed the intermediary model involved in the ManyToMany relashionship. Sorry. When I tried that I kept running into this error: "Cannot set values on a ManyToManyField which specifies an intermediary model. Use foo.FilmRole's Manager instead. As you are using an intermediary model, you must insert multiple FilmRole, one for each actor to this film, but you don't want using a formset, do you?. Is the following going toward your goal? # forms.py class FilmActorsForm(forms.Form): actors = forms.ModelMultipleChoiceField(queryset=Actors..., required=...) # views.py def assign_actors(film_id): film = get_object_or_404(Film, id=film_id) if request.method == 'POST': form = FilmActorsForm(request.POST) if form.is_valid(): chosen_actors = form.cleaned_data['actors'] current_actors = film.actors.all() # handle deletion / creation of filmroles return HttpResponseRedirect(...) else: form = FilmActorForm() Regards, -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
Re: Form/view for ManyToMany relationship
On Thu, Mar 3, 2011 at 11:50 AM, werefr0g wrote: > Hello, > > Sorry if I misunderstand, but what is wrong about using a ModelForm on your > Film bounded to the film instance? When I tried that I kept running into this error: "Cannot set values on a ManyToManyField which specifies an intermediary model. Use foo.FilmRole's Manager instead." ... which led me down a different path but perhaps I should have persevered more. I have googled this error extensively and spent some time digging into Django internals to figure out what is happening. Basically I can see that if Django didn't auto-generate the relationship manager class then it will throw this error. Conceptually I totally get why that is (it has no way of knowing what values to assign to the extra fields). What I don't get is how I'm supposed to get around it. Lets say I wanted to put some code somewhere to munge the missing fields to some default value. Where would I put that code? I can't relate to the error message at all. I read about manager classes and how I can override query sets and so on. Sure that totally makes sense. But how does that help me here?How can I use the manager for FilmRole? Do I need to override some method in my manager? Which method? An example would be really useful here. Thanks. -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
Re: Form/view for ManyToMany relationship
Hello, Sorry if I misunderstand, but what is wrong about using a ModelForm on your Film bounded to the film instance? Regards -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
