How to make the instance inside Django form take multiple values? - django

Question

I'm making a Django blog and I want to make the user edit his post. I have 2 forms to render, Post Form that includes (title, post image, content, category) and another separated form for the post tags that includes (tag name). To edit the tags I have to get all the tags related to the post and set them to the instance attribute which takes only one object (and I have multiple tags for one post).
Here are my Models:
class PostTags(models.Model):
tag_name = models.CharField(max_length=100)
def __str__(self):
return self.tag_name
class Post(models.Model):
title = models.CharField(max_length=50)
picture = models.ImageField(null=True,upload_to='images/')
content = models.CharField(max_length=255)
likes = models.ManyToManyField(User,blank=True,related_name='likes')
dislikes = models.ManyToManyField(User,blank=True,related_name='dislikes')
date_of_publish = models.DateTimeField(auto_now_add=True,null=True,blank=True)
user = models.ForeignKey(User,on_delete=models.CASCADE)
category = models.ForeignKey(Category,on_delete=models.CASCADE)
tag = models.ManyToManyField(PostTags,blank=True)
def __str__(self):
return self.title
Here are my Forms:
class PostForm(forms.ModelForm):
class Meta:
model = Post
fields = ['title','picture','content','category']
widgets = {
'title': forms.TextInput(attrs={'class': 'form-control'}),
'picture': forms.FileInput(attrs={'class': 'form-control'}),
'content':forms.TextInput(attrs={'class': 'form-control'}),
'category' : forms.Select(attrs={'class':'form-control'}),
}
class TagsForm(forms.ModelForm):
class Meta:
model = PostTags
fields = ['tag_name']
widgets = {
'tag_name': forms.TextInput(attrs={'class': 'form-control', 'data-role': 'tagsinput'})
}
and here is my try to get all tags in the tags form in views.py
def editPost(request,post_id):
post = Post.objects.get(id= post_id)
post_form = PostForm(instance=post)
# tagInstance = []
for tag in post.tag.all():
print(tag)
newTag = PostTags.objects.get(tag_name=tag)
tag_form = TagsForm(instance=newTag)
# tagInstance.append(newTag)
# print(tagInstance)
# if request.method == 'POST':
# form = PostForm(request.POST,instance=post)
# if form.is_valid():
# form.save()
# return redirect('post')
context = {"post_form":post_form,'tag_form':tag_form}
return render (request,"dj_admin/editpost.html",context)
The above try resulted in only the last tag rendered to the tags form which is expected

Answer 1

There is probably a cleaner solution but this should work:
def editPost(request,post_id):
post = Post.objects.get(id= post_id)
post_form = PostForm(instance=post)
context = {}
context['post_form'] = post_form
count = 0
for tag in post.tag.all():
print(tag)
newTag = PostTags.objects.get(tag_name=tag)
tag_form = TagsForm(instance=newTag)
count += 1
context['tag_form'+str(count)] = TagsForm(instance=newTag)
context['tag_form_counter'] = count
return render (request,"dj_admin/editpost.html",context)
So, in your template you must to check the tag_form_counter variable to know how many tag_forms you have. And make a forloop to show them.

Answer 2

If I understood you correctly, you want to render all tag_forms related to the post inside your template.
You can achieve what you want using django model inline_formsets
forms.py:
from django.forms import inlineformset_factory
from .models import Post, PostTags
class PostForm(forms.ModelForm):
class Meta:
model = Post
fields = ['title','picture','content','category']
widgets = {
'title': forms.TextInput(attrs={'class': 'form-control'}),
'picture': forms.FileInput(attrs={'class': 'form-control'}),
'content':forms.TextInput(attrs={'class': 'form-control'}),
'category' : forms.Select(attrs={'class':'form-control'}),
}
class TagsForm(forms.ModelForm):
class Meta:
model = PostTags
fields = ['tag_name']
widgets = {
'tag_name': forms.TextInput(attrs={'class': 'form-control', 'data-role': 'tagsinput'})
}
TagFormSet = inlineformset_factory(PostTags, Post, fields=('tag_name',))
views.py:
from .forms import PostForm, TagsForm, TagFormSet
def editPost(request,post_id):
post = Post.objects.get(id= post_id)
post_form = PostForm(instance=post)
tag_formset = TagFormSet(instance=post)
if request.method == 'POST':
form = PostForm(request.POST, instance=post)
tag_formset = TagFormSet(request.POST, instance=post)
if form.is_valid() and tag_formset.is_valid():
form.save()
tag_formset.save()
return redirect('post')
context = {'post_form': post_form, 'tag_formset': tag_formset}
return render (request, 'dj_admin/editpost.html', context)
and then inside your template file you can simply add {{ tag_formset }} like this:
<form method="post">
{{ formset }}
</form>