针对以下用于Flask的ajax post请求(如何在Flask中使用从ajax发送的数据？):
$.ajax({
url: "http://127.0.0.1:5000/foo",
type: "POST",
contentType: "application/json",
data: JSON.stringify({'inputVar': 1}),
success: function( data ) {
alert( "success" + data );
}
});
我遇到了一个Cross Origin Resource Sharing (CORS)错误:
No 'Access-Control-Allow-Origin' header is present on the requested resource.
Origin 'null' is therefore not allowed access.
The response had HTTP status code 500.
我尝试了以下两种方法来解决问题，但似乎都没有起作用。
- 使用 Flask-CORS
这是一个用于处理 CORS 的 Flask 扩展，应该可以实现跨域 AJAX。
- http://flask-cors.readthedocs.org/en/latest/
- 如何在 Flask 和 Heroku 中启用 CORS
- 当应用 jwt auth wrapper 时 Flask-cors 包装器不起作用。
- JavaScript - 请求的资源上不存在 'Access-Control-Allow-Origin' 标头
我的 pythonServer.py 使用了这个解决方案：
from flask import Flask
from flask.ext.cors import CORS, cross_origin
app = Flask(__name__)
cors = CORS(app, resources={r"/foo": {"origins": "*"}})
app.config['CORS_HEADERS'] = 'Content-Type'
@app.route('/foo', methods=['POST','OPTIONS'])
@cross_origin(origin='*',headers=['Content-Type','Authorization'])
def foo():
return request.json['inputVar']
if __name__ == '__main__':
app.run()
- 使用特定的Flask装饰器
这是一个官方的Flask代码片段，定义了一个装饰器，可以允许在其修饰的函数上进行CORS。
- http://flask.pocoo.org/snippets/56/
- Python Flask跨站点HTTP POST - 对于特定的允许来源不起作用
- http://chopapp.com/#351l7gc3
我的pythonServer.py使用此解决方案：
from flask import Flask, make_response, request, current_app
from datetime import timedelta
from functools import update_wrapper
app = Flask(__name__)
def crossdomain(origin=None, methods=None, headers=None,
max_age=21600, attach_to_all=True,
automatic_options=True):
if methods is not None:
methods = ', '.join(sorted(x.upper() for x in methods))
if headers is not None and not isinstance(headers, basestring):
headers = ', '.join(x.upper() for x in headers)
if not isinstance(origin, basestring):
origin = ', '.join(origin)
if isinstance(max_age, timedelta):
max_age = max_age.total_seconds()
def get_methods():
if methods is not None:
return methods
options_resp = current_app.make_default_options_response()
return options_resp.headers['allow']
def decorator(f):
def wrapped_function(*args, **kwargs):
if automatic_options and request.method == 'OPTIONS':
resp = current_app.make_default_options_response()
else:
resp = make_response(f(*args, **kwargs))
if not attach_to_all and request.method != 'OPTIONS':
return resp
h = resp.headers
h['Access-Control-Allow-Origin'] = origin
h['Access-Control-Allow-Methods'] = get_methods()
h['Access-Control-Max-Age'] = str(max_age)
if headers is not None:
h['Access-Control-Allow-Headers'] = headers
return resp
f.provide_automatic_options = False
return update_wrapper(wrapped_function, f)
return decorator
@app.route('/foo', methods=['GET','POST','OPTIONS'])
@crossdomain(origin="*")
def foo():
return request.json['inputVar']
if __name__ == '__main__':
app.run()
你能否请给出一些为什么的指示？