基於類的視圖，可插拔視圖
從Django學來的
好處：
類可以繼承
代碼可以複用
可以定義多種行爲
from flask import Flask, request
from flask.views import View
app = Flask(__name__)
class UserView(View):
methods = ['GET', 'POST']
def get(self):
return 'get'
def post(self):
return 'post'
# 分配請求
def dispatch_request(self):
dispatch_pattern = {'GET': self.get, 'POST': self.post}
method = request.method
return dispatch_pattern.get(method)()
app.add_url_rule(
'/user',
view_func=UserView.as_view('user'),
methods=["GET", "POST"]
)
if __name__ == '__main__':
app.run(debug=True)
裝飾這個類視圖
由於會被as_view轉換，所以需要顯式的裝飾它
def log_time(f):
def decorator(*args, **kwargs):
print(time.time())
return f(*args, **kwargs)
return decorator
f = UserView.as_view('user')
log_time(f)
app.add_url_rule(
'/user',
view_func=f,
methods=["GET", "POST"]
)
使用`MethodView`
from flask import Flask, request
from flask.views import View, MethodView
app = Flask(__name__)
class ProjectView(MethodView):
def get(self):
return 'get'
def post(self):
return 'post'
app.add_url_rule(
'/project',
view_func=ProjectView.as_view('project'),
methods=["GET", "POST"]
)
if __name__ == '__main__':
app.run(debug=True)
這個類就是繼承了View然後重寫了dispatch_request
def dispatch_request(self, *args, **kwargs):
meth = getattr(self, request.method.lower(), None)
# If the request method is HEAD and we don't have a handler for it
# retry with GET.
if meth is None and request.method == "HEAD":
meth = getattr(self, "get", None)
assert meth is not None, "Unimplemented method %r" % request.method
return meth(*args, **kwargs)
相當於
class MethodView:
def get(self):
print('get')
return 'get'
def post(self):
print('post')
return 'post'
def dispatch_request(self):
func = getattr(self, 'get', None)
return func()
MethodView().dispatch_request()
func = getattr(self, 'get', None)
使用MethodView實現reful風格接口
from flask.views import MethodView
from flask import Flask
app = Flask(__name__)
class ProjectView(MethodView):
def get(self, project_id):
if project_id is None:
return 'ALL projects'
return f'get {project_id}'
def post(self, project_id):
return f'post {project_id}'
def put(self, project_id):
return f'put {project_id}'
def delete(self, project_id):
return f'delete {project_id}'
f = ProjectView.as_view('projects')
app.add_url_rule('/projects/<project_id>', view_func=f, methods=['GET', 'POST', 'PUT', 'DELETE'])
app.add_url_rule('/projects/', defaults={"project_id": None}, view_func=f, methods=['GET'])
if __name__ == '__main__':
app.run()
request獲取請求數據
get
get_data = request.args
表單
form_data = request.form
json
json_data = request.json
file
file_data = request.files
上傳文件的代碼
html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="/uploads" method="post" enctype="multipart/form-data">
<input type="file" name="pic">
<input type="submit">
</form>
</body>
</html>
python代碼
# -*- encoding: utf-8 -*-
"""
@File : homework.py
@Time : 2020/6/16 7:18 上午
@Author : zhongxin
@Email : [email protected]
"""
import os
import time
from flask import Flask, request, render_template, redirect
app = Flask(__name__)
print(app.instance_path)
print(app.root_path)
print(app.static_folder)
@app.route('/')
def index():
return render_template('index.html')
@app.route('/uploads', methods=['POST'])
def upload():
file = request.files.get('pic')
if not file:
return render_template('index.html')
file_name = time.strftime('%Y-%m-%d-%H-%M-%S') + file.filename
file_url = f'/static/{file_name}'
file.save(os.path.join(
app.root_path,
app.static_folder,
file_name
))
return redirect(file_url)
if __name__ == '__main__':
app.run()
