How to convert string to CharField - django

Question

In my project there is an opportunity even for unauthorized users to leave a comment to a post. So, I have commentForm:
class CommentForm(forms.ModelForm):
class Meta:
model = Comment
fields = ('author', 'text',)
and model:
class Comment(models.Model):
post = models.ForeignKey('blog.Post', on_delete=models.CASCADE, related_name='comments')
author = models.CharField(max_length=200)
text = models.TextField()
If user is authorized, I want to substitute to author fileld username and don't show the input on page, otherwise site visitor should fill this input himself. I've tried to write this in appropriate view:
if request.user.is_authenticated:
form = CommentForm(request.POST, initial={'author': request.user.username})
But form.is_valid is false.
Then I've tried:
if request.user.is_authenticated:
form.fields['author'] = request.user.username
During form validating appeared 'string' object has no attribute 'disabled'.
The question is how to deal with it the right way? Thanks.
post_detail.html
{% extends 'blog/base.html' %}
{% block content %}
<div class="post">
{% if post.published_date %}
<div class="date">
{{ post.published_date }}
</div>
{% else %}
<a class="btn btn-default" href="{% url 'post_publish' post_id=post.pk blog_id=blog.pk %}">Publish</a>
{% endif %}
{% if user.is_authenticated and user == post.blog.author%}
<a class="btn btn-default" href="{% url 'post_remove' post_id=post.pk blog_id=blog.pk %}">удалить</a>
<a class="btn btn-default" href="{% url 'post_edit' post_id=post.pk blog_id=blog.pk %}">редактировать</a>
{% endif %}
<h1>{{ post.title }}</h1>
<p>{{ post.text|safe|linebreaks }}</p>
</div>
<hr>
<p>New comment</p>
<form method="POST" class="post-form">{% csrf_token %}
<!-- HERE I HIDE AUTHOR FIELD FROM LOGGED IN USERS -->
{% if user.is_authenticated %}
{{ form.text }}
{{ form.text.errors }}
{% else %}
{{ form.as_p }}
{% endif %}
<button type="submit" class="save btn btn-default">Send</button>
</form>
{% for comment in post.comments.all %}
<div class="comment">
<div class="date">
{{ comment.created_date }}
<!-- {% if not comment.approved_comment %} -->
<a class="btn btn-default" href="{% url 'comment_remove' post_id=post.pk blog_id=blog.pk com_id=comment.pk %}">удалить</a>
<!-- {% endif %}-->
</div>
<strong>{{ comment.author }}</strong>
<p>{{ comment.text|linebreaks }}</p>
</div>
{% empty %}
<p>No comments here yet :(</p>
{% endfor %}
{% endblock %}
views.py
from .models import Post, Comment, Blog
from django.shortcuts import render
from django.utils import timezone
from django.shortcuts import render, get_object_or_404
from .forms import PostForm, CommentForm, BlogForm
from django.shortcuts import redirect
from django.contrib.auth.decorators import login_required
from django.contrib.auth import logout, login
from django.contrib.auth.models import User
def post_detail(request, blog_id, post_id):
blog = get_object_or_404(Blog, pk=blog_id)
post = get_object_or_404(Post, pk=post_id)
if request.method == "POST":
form = CommentForm(request.POST)
if form.is_valid():
comment = form.save(commit=False)
if request.user.is_authenticated:
comment.author = request.user.username
comment.post = post
comment.save()
return redirect('post_detail', blog_id=blog_id, post_id=post.pk)
else:
form = CommentForm()
return render(request, 'blog/post_detail.html', {'post': post, 'blog': blog, 'form': form})
#login_required
def post_publish(request, blog_id, post_id):
post = get_object_or_404(Post, pk=post_id)
post.publish()
return redirect('post_detail', blog_id=blog_id, post_id=post.pk)
#login_required
def post_remove(request, blog_id, post_id):
post = get_object_or_404(Post, pk=post_id)
post.delete()
return redirect('post_list', blog_id=blog_id)
#login_required
def comment_remove(request, blog_id, post_id, com_id):
comment = get_object_or_404(Comment, pk=com_id)
comment.delete()
return redirect('post_detail', blog_id=blog_id, post_id=post_id)
#login_required
def post_edit(request, blog_id, post_id):
post = get_object_or_404(Post, pk=post_id)
if request.method == "POST":
form = PostForm(request.POST, instance=post)
if form.is_valid():
post = form.save(commit=False)
post.author = request.user
post.save()
return redirect('post_detail', blog_id = blog_id, post_id=post.pk)
else:
form = PostForm(instance=post)
return render(request, 'blog/post_edit.html', {'form': form})
def post_list(request, blog_id):
blog = get_object_or_404(Blog, pk=blog_id)
posts = blog.posts.all().filter(published_date__isnull=False).order_by('published_date')
return render(request, 'blog/post_list.html', {'posts': posts, 'blog': blog})

Answer 1

I don't know if this is the best way to solve my problem, but it helped:
change a form value before validation in Django form