[Day 08] Django channels 範例（上）

2023 iThome 鐵人賽

DAY 8

AI & Data

已 django + channels 來取得即時股價資料的推播系列第 8 篇

15th鐵人賽 django channels

條天千

2023-09-16 11:21:39

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首先!

建立 chat app 專案 + 安裝套件

cd C:\builds\django_channels_realtime\django_channels
python3 manage.py startapp chat

python3 -m pip install -U 'channels[daphne]'

建立後專案結構為

chat/
    __init__.py
    admin.py
    apps.py
    models.py
    tests.py
    views.py

接下來會需要再 django_channels/settings.py 新增程式碼
(接下來範例都會使用 # + 路徑來代表開啟哪個檔案)

# django_channels/settings.py
import os # 新增
...
ASGI_APPLICATION = "django_channels.asgi.application"
...
INSTALLED_APPS = [
    'chat', # 新增
    'daphne',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]
...
TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR, 'chat', 'templates')], # 新增
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

建立新的ＨＴＭＬ檔案，用來呈現聊天室的網頁
位置：django_channels/chat/templates/chat/index.html

<!-- chat/templates/chat/index.html -->
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8"/>
    <title>Chat Rooms</title>
</head>
<body>
    What chat room would you like to enter?<br>
    <input id="room-name-input" type="text" size="100"><br>
    <input id="room-name-submit" type="button" value="Enter">

    <script>
        document.querySelector('#room-name-input').focus();
        document.querySelector('#room-name-input').onkeyup = function(e) {
            if (e.key === 'Enter') {  // enter, return
                document.querySelector('#room-name-submit').click();
            }
        };

        document.querySelector('#room-name-submit').onclick = function(e) {
            var roomName = document.querySelector('#room-name-input').value;
            window.location.pathname = '/chat/' + roomName + '/';
        };
    </script>
</body>
</html>

以上為建立聊天室的ＨＴＭＬ，

# chat/views.py
from django.shortcuts import render


def index(request):
    return render(request, "chat/index.html")

建立 django 和 html 的關聯

# chat/urls.py
from django.urls import path

from . import views


urlpatterns = [
    path("", views.index, name="index"),
]

建立網頁地址與網頁呈現的關聯

# django_channels/urls.py
from django.contrib import admin
from django.urls import include, path

urlpatterns = [
    path("chat/", include("chat.urls")),
    path("admin/", admin.site.urls),
]

建立根目錄與分支的網址關聯
意含透過 /chat/ -> 呈現 index.html 的程式碼

# django_channels/asgi.py
import os

from channels.routing import ProtocolTypeRouter
from django.core.asgi import get_asgi_application

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "django_channels.settings") #這段告訴 django 他的設定目錄在哪裡

application = ProtocolTypeRouter(
    {
        "http": get_asgi_application(),
        # Just HTTP for now. (We can add other protocols later.)
    }
)