django StreamingHttpResponse fetchEventSource实现前后端流试返回数据并接收数据的完整详细过程

django后端环境介绍：

Python 3.10.14
pip install django-cors-headers==4.4.0 Django==5.0.6 django-cors-headers==4.4.0 djangorestframework==3.15.2  -i https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple
总环境如下：
Package             Version
------------------- -------
asgiref             3.8.1
Django              5.0.6
django-cors-headers 4.4.0
djangorestframework 3.15.2
pip                 24.2
setuptools          75.1.0
sqlparse            0.5.3
typing_extensions   4.12.2
wheel               0.44.0

1、创建项目

django-admin startproject event_stream_test
cd event_stream_test
python  manage.py  startapp  sse

总的目录结构如下：

event_stream_test/settings.py中的配置如下：

INSTALLED_APPS = [
......"sse.apps.SseConfig","corsheaders",
......
]
MIDDLEWARE = [
......"django.contrib.sessions.middleware.SessionMiddleware","corsheaders.middleware.CorsMiddleware", # 这个位置要在CommonMiddleware之前"django.middleware.common.CommonMiddleware",
......
]
# 允许跨域设置
CORS_ALLOW_CREDENTIALS = True
CORS_ALLOW_ALL_ORIGINS = True
CORS_ALLOW_HEADERS = ('*')完整的settings设置如下：
"""
Django settings for event_stream_test project.Generated by 'django-admin startproject' using Django 4.2.For more information on this file, see
https://docs.djangoproject.com/en/4.2/topics/settings/For the full list of settings and their values, see
https://docs.djangoproject.com/en/4.2/ref/settings/
"""
import os
from pathlib import Path# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/4.2/howto/deployment/checklist/# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = "django-insecure-u@my#&53d3%e79ox#u!rs0eprc$c)_2gbcezpdj0v^=_(!wwu-"# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = TrueALLOWED_HOSTS = []# Application definitionINSTALLED_APPS = ["django.contrib.admin","django.contrib.auth","django.contrib.contenttypes","django.contrib.sessions","django.contrib.messages","django.contrib.staticfiles","sse.apps.SseConfig","corsheaders",# "rest_framework"]MIDDLEWARE = ["django.middleware.security.SecurityMiddleware","django.contrib.sessions.middleware.SessionMiddleware","corsheaders.middleware.CorsMiddleware","django.middleware.common.CommonMiddleware","django.middleware.csrf.CsrfViewMiddleware","django.contrib.auth.middleware.AuthenticationMiddleware","django.contrib.messages.middleware.MessageMiddleware","django.middleware.clickjacking.XFrameOptionsMiddleware",
]ROOT_URLCONF = "event_stream_test.urls"TEMPLATES = [{"BACKEND": "django.template.backends.django.DjangoTemplates",# "DIRS": [os.path.join(BASE_DIR, 'sse/templates')],"DIRS": [],"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",],},},
]WSGI_APPLICATION = "event_stream_test.wsgi.application"# Database
# https://docs.djangoproject.com/en/4.2/ref/settings/#databasesDATABASES = {"default": {"ENGINE": "django.db.backends.sqlite3","NAME": BASE_DIR / "db.sqlite3",}
}# Password validation
# https://docs.djangoproject.com/en/4.2/ref/settings/#auth-password-validatorsAUTH_PASSWORD_VALIDATORS = [{"NAME": "django.contrib.auth.password_validation.UserAttributeSimilarityValidator",},{"NAME": "django.contrib.auth.password_validation.MinimumLengthValidator",},{"NAME": "django.contrib.auth.password_validation.CommonPasswordValidator",},{"NAME": "django.contrib.auth.password_validation.NumericPasswordValidator",},
]# Internationalization
# https://docs.djangoproject.com/en/4.2/topics/i18n/LANGUAGE_CODE = "en-us"TIME_ZONE = "UTC"USE_I18N = TrueUSE_TZ = True# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/4.2/howto/static-files/STATIC_URL = "static/"# Default primary key field type
# https://docs.djangoproject.com/en/4.2/ref/settings/#default-auto-fieldDEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
CORS_ALLOW_CREDENTIALS = True
CORS_ALLOW_ALL_ORIGINS = True
CORS_ALLOW_HEADERS = ('*')

event_stream_test/urls.py中的配置如下：

from django.contrib import admin
from django.urls import path, includeurlpatterns = [path("admin/", admin.site.urls),path('v1/sse/', include('sse.urls'))
]

sse/urls.py中的配置如下：

from django.urls import path
from sse import viewsurlpatterns = [# SSEpath('demo', views.DemoAPIView.as_view()),
]

sse/views.py中的配置如下：

import time
from django.http import StreamingHttpResponse
from rest_framework.views import APIViewclass DemoAPIView(APIView):# def post(self, request):def get(self, request):# 定义一个生成器，持续输出数据流def event_stream():# 测试读取当前文件# with open('sse/1.txt', mode="r", encoding='utf-8') as file:#     for line in file:#         time.sleep(3)#         yield f'data: {line}\n\n'#count = 0while True:count = count+1line = "当前行号是"+str(count)yield f'data: {line}\n\n'time.sleep(3)response = StreamingHttpResponse(event_stream(), content_type='text/event-stream; charset=utf-8',headers={'Cache-Control': 'no-cache'}, status=200)return response

至此配置django配置已经完成，运行项目则可以直接在浏览器中看到结果：

python manage.py runserver然后在浏览器中输入：
http://127.0.0.1:8000/v1/sse/demo
即可看到如下内容，会一直不停地打印

前端环境介绍：

"dependencies": {"@microsoft/fetch-event-source": "^2.0.1","vue": "^3.5.13"},

需要安装npm i @microsoft/fetch-event-source
最好版本一致

Vue3代码如下（App.vue下）

<template><h1>这是测试页</h1><h1 v-for="item in data" style="color: red">{{ item }}</h1>
</template><script setup>
import {ref, onMounted, onUnmounted} from "vue";
import {fetchEventSource} from '@microsoft/fetch-event-source';
const controller = new AbortController();
const data = ref([])
const connectSSE = async () => {const url = "http://127.0.0.1:8000/v1/sse/demo"console.log(url)await fetchEventSource(url, {method: 'GET',headers: {'Accept': '*/*',  // 这个很重要// "Content-Type": "text/event-stream"},// 发送请求的内容可以放在body中// body: JSON.stringify({//   "type": "auto",//   "text": "阿斯蒂芬",//   "background": "",//   "messages": [],//   "meta_data": {}// }),signal: controller.signal,openWhenHidden: true, // 当不在当前页面时页面依然能不间断的接收数据onmessage: async (event) => {console.log('event', event)// console.log("JSON.parse(event.data)===》", JSON.parse(event.data))// console.log('event.data.split("是")', event.data.split("是"));let num = parseInt(event.data.split("是")[1])console.log("num", num)if (num === 3){console.log("终止进程没")  // 在上边写这个signal: controller.signal,在这写controller.abort()可以终止接收后端的推送controller.abort()}else {data.value.push(event.data)}},onerror(err) {console.error('Error:', err);if (err.status === 500) {// 服务器错误时重新连接setTimeout(() => connectSSE(), 5000);}},onopen(response) {if (response.ok) {console.log('Connection start');}},onclose() {console.log('Connection close');}})
}
onMounted(() => {connectSSE();
});
onUnmounted(() => {
});
</script>

运行前端项目npm run dev 并打开前端页面，展示结果如下：

如果把前端中的这段代码替换成data.value.push(event.data)

//if (num === 3){
// console.log("终止进程没")  // 在上边写这个signal: controller.signal,在这写controller.abort()可以终止接收后端的推送
//  controller.abort()
//}else {
//  data.value.push(event.data)
//}
替换为：
data.value.push(event.data)

则效果如下：会一直打印，不会终止接收，所以controller.abort()得作用就是终止接收后端的推送

如果把openWhenHidden: true,也给注释了则在切换页面后会重新接收数据，效果如下

跨域设置可参考
流试说明可参考