[PYTHON] How to upload files in Django generic class view

2020-04-07 Created: windows10 / Python-3.8.2-amd64 / Django-3.0.4

How to upload files in generic class view in Django There is not much information in Japanese. Therefore, it took a long time. I will write an article so that I will not forget it. This article is for those who want a quick understanding of the principles of file uploads.

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Preparation

The project name is mysite and the application name is fileupload. Create a folder media in mysite / and use it as a file storage location.

The file layout up to this point is as follows.

mysite/
    mysite/
        __pycashe__/    <-do not worry about
        setting.py, urls.py etc.*.5 py
    fileupload/
        migrations/     <-do not worry about
        models.py, views.py etc.*.6 py
    media/              <-Where to save the uploaded file
    manage.py           <-For project management

Register the application fileupload in your Django project. Therefore, add it to INSTALLED_APPS in settings.py.

mysite/mysite/settings.py

INSTALLED_APPS = [
    'fileupload.apps.FileuploadConfig',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]

Also register a directory for uploading files. For that, add two lines to settings.py.

mysite/mysite/settings.py

MEDIA_ROOT = os.path.join(BASE_DIR, 'media')
MEDIA_URL = '/media/'

Added to urls.py to register url.

mysite/mysite/urls.py

from django.contrib import admin
from django.urls import include, path
from django.conf import settings
from django.conf.urls.static import static

urlpatterns = [
    path('fileupload/', include('fileupload.urls')),
    path('admin/', admin.site.urls),
] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

Application implementation

Create a model Fileupload. There are two fields, the title of the file and the file itself. The file is saved in a folder named media / uploads / year / month / day. Assuming that you are uploading photos, the extension is only jpg.

mysite/fileupload/models.py

from django.db import models
from django.core.validators import FileExtensionValidator

class Fileupload(models.Model):
    titlefield = models.CharField(max_length = 200, null = True)
    filefield = models.FileField(
        upload_to = 'uploads/%Y/%m/%d/',
        verbose_name = 'attached file',
        validators=[FileExtensionValidator(['jpg', ])],
        null = True
    )

Create a view. After all, it's easy to use Django's generic class view. The generic class view has default variable names, file names, etc. You cannot use it without knowing (for example, fileupload_object_name or template_name). That's why I explicitly gave it a descriptive name instead of the default name.

mysite/fileupload/views.py

from django.views import generic
from .models import Fileupload

class FileuploadListView(generic.ListView):
    model = Fileupload
    context_object_name = 'fileupload_context_list'

class FileuploadCreateView(generic.CreateView):
    model = Fileupload
    fields = ['titlefield', 'filefield']
    success_url = '/fileupload'
    template_name = 'fileupload/fileupload_create.html'

class FileuploadDetailView(generic.DetailView):
    model = Fileupload
    template_name = 'fileupload/fileupload_detail.html'
    context_object_name = 'fileupload_context'

class FileuploadUpdateView(generic.UpdateView):
    model = Fileupload
    fields = ['titlefield', 'filefield']
    success_url = '/fileupload'
    template_name = 'fileupload/fileupload_update.html'

class FileuploadDeleteView(generic.DeleteView):
    model = Fileupload
    success_url = '/fileupload'
    template_name = 'fileupload/fileupload_delete.html'

Register the view in the url. Create a new file fileupload / urls.py. Register the created view.

mysite/fileupload/urls.py

from django.urls import path
from . import views

urlpatterns = [
    path('', views.FileuploadListView.as_view()),
    path('index', views.FileuploadListView.as_view(),
        name = 'site_index'),
    path('create', views.FileuploadCreateView.as_view(),
        name = 'site_create'),
    path('detail/<int:pk>', views.FileuploadDetailView.as_view(),
        name = 'site_detail'),
    path('update/<int:pk>', views.FileuploadUpdateView.as_view(),
        name = 'site_update'),
    path('delete/<int:pk>', views.FileuploadDeleteView.as_view(),
        name = 'site_delete'),
]

Create an html file for the template in fileupload / templates / fileupload /. Corresponds to each view.

mysite/fileupload/templates/fileupload/fileupload_list.html

<h1>List files</h1>

{% if fileupload_context_list %}
  <table>
  {% for temp in fileupload_context_list %}
    <tr>
      <td><a href = "{% url 'site_detail' temp.pk %}"> {{ temp.titlefield }}</a></td>
      <td>{{ temp.filefield }}</td>
      <td><a href = "{% url 'site_update' temp.pk %}">Edit</a></td>
      <td><a href = "{% url 'site_delete' temp.pk %}">Delete</a></td>
    </tr>
  {% endfor %}
  </table>

{% else %}
<p>No file available.</p>

{% endif %}
<p><a href = "{% url 'site_create' %}">Upload new file</a></p>

mysite/fileupload/templates/fileupload/fileupload_create.html

<h1>File upload</h1>

<form method = "post" enctype="multipart/form-data">
    {% csrf_token %}
    {{ form.titlefield }}
    {{ form.filefield }}
    <input type = "submit" value = "Create" />
</form>

mysite/fileupload/templates/fileupload/fileupload_detail.html

<h1>File details</h1>

{% if fileupload_context %}
  <ul>
    <li>Primary Key Number : {{ fileupload_context.pk }}</li>
    <li>Memo Text : {{ fileupload_context.titlefield }}</li>
    <li>Memo Text : /media/{{ fileupload_context.filefield }}</li>
    <li>File : <img src = /media/{{ fileupload_context.filefield }} /></li>
  </ul>

{% else %}
<p>No file available.</p>

{% endif %}
<p><a href = "{% url 'site_index' %}">List files</a></p>

mysite/fileupload/templates/fileupload/fileupload_update.html

<h1>File update</h1>

<form method = "post" enctype="multipart/form-data">
    {% csrf_token %}
    {{ form.titlefield }}
    {{ form.filefield }}
    <input type = "submit" value = "Save" />
</form>

mysite/fileupload/templates/fileupload/fileupload_delete.html

<h1>Delete file</h1>

<form method = "post">
    {% csrf_token %}
    <input type= "submit" value = "Delete" />
</form>

Finish

Once you've done the migration and started your development www server, You can access it at http: // localhost: 8000 / fileupload /.

Task

The process when the file upload fails is not written properly, so it is a future issue.

The end