Question

I strongly suspect that this boils down to me needing to understand some language construct better, but I don’t know where to start, so I’m just going to have to throw some code out.

models:

class BlogTag(models.Model):
    tag = models.CharField(max_length=255)

    def __unicode__(self):
        return self.tag

class BlogEntry(models.Model):
    title = models.CharField(max_length=255)
    body = models.TextField()
    date = models.DateTimeField()
    tags = models.ManyToManyField(BlogTag)

    def __unicode__(self):
        return self.title

form:

class BlogForm(ModelForm):
    class Meta:
        model = BlogEntry

view:

title='New Blog Entry'
if request.method=='POST':
    form=BlogForm(request.POST)
    if form.is_valid():
        cd=form.cleaned_data
        blogEntry=BlogEntry(**cd)
        blogEntry.save()
else:
    form=BlogForm();
return render_to_response('blog_add.html', locals())

By using **cd I was able to take the cleaned data directly into my object, which is obviously desireable because this way the view is loosely coupled to the other objects — I can change the model, and everything else changes with it without me having to do a thing.

Unfortunately, I’m getting an error that:

'tags' is an invalid keyword argument for this function

I could always break down the CD and build a manual dictionary approach of blogEntry=BlogEntry(title=cd[‘title’]…) and then just add the tags in one by one, but… I should have better options than that, and I just don’t know what they are 🙁

Answer 1

I think what it boils down to is that **cd will pass in the arguments as a dictionary. BlogEntry is expecting a BlogTag type for tags instead you are passing it the dictionary argument which is not the right type. First create a BlogTag object and then pass that in to BlogEntry

This might help http://anubis.blasux.ru/books/Python/www.djangoproject.com/documentation/0.96/models/many_to_many/