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PODjango ModelForm Instantiation after Form Creation
 

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  1. PODjango ModelForm Instantiation after Form Creation
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    <p>I have a form that consists of a response for each entry in another model. At the time the form is generated the response to each item may or may not exist. I need a form that allows me to update the response if it exists and create it with the form post data if it doesn't exist.</p> <p>Currently I am iterating through a range and creating my forms with the post data:</p> <pre><code>forms = [SpecialNoteForm(request.POST, prefix=str(x), ) for x in rang(1,3)] </code></pre> <p>I am doing this because I don't know how else to access the form data cleanly in order to identify the object that the form should be instantiated with. I tried doing something like this after the forms list was created because i can then access the form data:</p> <pre><code>for form in forms: try: instance = SpecialNote.objects.get(flag=form["flag"].data, host=form["host"].data) form.instance = instance form.save() </code></pre> <p>The errors on the form persist after I do this, however. I need a way of accessing the data I need to instantiate the object at the time of form creation or a way of re-evaluating the form after i've attached an instance to it.</p> <p><strong>EDIT</strong></p> <p>I ran into the same problem with model formsets as I did with my initial approach--I don't know how to instantiate the forms while at the same time allowing for intial values on forms that don't have an instance. I don't want to create all of the model instances before hand because it is import whether or not the user has submitted these with the required fields filled in.</p> <p>My current approach is still using the model forms:</p> <pre><code>forms = [] for n in form_range(request.POST): # calculates number of forms based on post data try: instance = SpecialNote.objects.get(flag=request.POST.get('%s'%n+'-flag'), host=request.POST.get('%s'%n+'-host')) except: instance = None forms.append(SpecialNoteForm(request.POST, prefix=str(n), instance=instance)) for form in forms: if form.is_valid(): form.save() </code></pre> <p>In summary, the problem with formsets is I don't know how to properly instantiate the forms without having them be queriable, i.e. already in the database. The problem with using regular model forms and a prefix is that getting the objects that i need to instantiate them with is messy (as you can see from my current approach). I'm looking for a solution to either of these two problems.</p>
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