[Django memo] I want to set the login user information in the form in advance

Thing you want to do

When posting a new post on the posting site, instead of typing in your own name, you want to set the logged-in user's information (such as your name) in the form in advance and save the trouble of typing in your name.

1. Prepare the model

app/models.py

from django.db import models
from django.contrib.auth import get_user_model


class Post(models.Model):
    author = models.ForeignKey(get_user_model(), on_delete=models.CASCADE)
    title = models.CharField(max_length=100)
    content = models.TextField()

    def __str__(self):
        return self.title

Prepare a Post model and set up three fields [Poster, Title, Content]. ʻAuthor = models.ForeignKey (get_user_model (), on_delete = models.CASCADE)get_user_model ()calls the entire class of the currently logged-in user, and this one line calls the ʻauthor` field and the logged-in user. Is linked. There are several ways to refer to the user model, but it is not good to refer to the user model directly. Reference: https://djangobrothers.com/blogs/referencing_the_user_model/

2. Prepare the form.

app/forms.py

from django import forms
from .models import Post

class PostForm(forms.ModelForm):
    class Meta():
        model = Post
        fields = (
            'title',
            'content',
        )

This time, I used a model form. Create a PostForm class by inheriting the ModelForm included in forms.py provided by Django. Specify the model to be inherited by model = Post, and specify two fields except author. There is no need to bother to specify the author here.

3. Set the login user in the view

app/views.py

from django.shortcuts import render, redirect
from .models import Post
from . import forms

def form_view(request):
    if request.method == 'POST':
        form = forms.PostForm(request.POST)
        if form.is_valid():
            post = form.save(commit=False)
            post.author = request.user
            post.save()
            return redirect('sns:index')
    else:
       form = forms.PostForm()
    return render(request, 'sns/form_view.html', {'form': form})

In the form_view function, it is necessary to change the behavior depending on whether POST is received as request (ʻif request.method =='POST': ) or GET (ʻelse:). For example, when the button "New Post" is pressed and the form_view function is called by the URL dispatcher, the request becomes'GET', so the process of simply displaying the form is executed as shown below.

    else:
        form = forms.PostForm()
    return render(request, 'app/form_view.html', {'form': form})

When something is entered in the displayed form, the submit button is pressed, and the form_view function is called by the URL dispatcher, the request becomes'POST', so the code shown below is executed.

    if request.method == 'POST':
        form = forms.PostForm(request.POST)
        if form.is_valid():
            post = form.save(commit=False)
            post.author = request.user
            post.save()
            return redirect('app:index')

1. Store the information entered by form = forms.PostForm (request.POST) in form.
2. ʻif form.is_valid (): Check if the information entered with is correct, and save formwithpost = form.save (commit = False). At this time, set commit = False` in the argument and tell that it will be modified a little more before saving completely.
3. In post.author = request.user, specify the request ʻuser` (that is, the logged-in user) in the author field of post.
4. Save the contents entered in the form with post.save () and the logged-in user name.
5. Specify the redirect destination with return redirect ('app: index').