Question:

How to create forms in Django with multiple Many-to-Many fields in Models

Problem

I have these three models with two many-to-many fields in BlogPost models like

class Category(models.Model):

name = models.CharField(max_length=150)

def __str__(self) -> str:

return self.name

class Tag(models.Model):

name = models.CharField(max_length=150)

def __str__(self) -> str:

return self.name

class BlogPost(models.Model):

title = models.CharField(max_length=200)

author = models.ForeignKey(User , on_delete=models.CASCADE)

categories = models.ManyToManyField(Category)

tags = models.ManyToManyField(Tag)

content = models.TextField()

created_at = models.DateTimeField(auto_now_add=True)

updated_at = models.DateTimeField(auto_now=True)

def __str__(self):

return self.title

and form on the client side as follows

{% extends 'blog_project/base.html' %}

{% load widget_tweaks %}

{% block content %}

<h2 class='login-heading'> Create New Post </h2>

{% csrf_token %}

{% for field in form.visible_fields %}

<label for="{{ field.id_for_label }}">{{ field.label }}</label>

{% for error in field.errors %}

<span class="help-block">{{ error }}</span>

{% endfor %}

</div>

{% endfor %}

</div>

</form>

</div>

{% endblock%}

It allows me to select from the existing categories but not allow me to add other categories.

I want to create a form in Django that allows a user to select from the categories on the client side as well as create new categories or tags and save them to the database so that other users can select from these or search them at least.

Solution

For that, you will need to manually render a field the user can enter the name of the Category they want to create. You can access the entered value in your view, save it to the database, and add it to the Blog Post object.

Inside your HTML form tag, include:

Then in your view, you can access and save the entered value:

def add_blog(request) :

...

new_category = request.GET("new-category")

if new_category:

category = Category.objects.create(name=new_category)

...

# if you want to immediately add the new category to the instance of a BlogPost

blog_post = blog_post_form.save()

blog_post.categories.add(category)

Answered by: >McPherson