为某些域模式定义自定义错误处理程序？答案

【问题标题】：Defining custom error handlers for certain domain patterns?为某些域模式定义自定义错误处理程序？
【发布时间】：2021-10-06 19:07:51
【问题描述】：

我正在使用 Flask，我想知道是否可以根据域模式自定义错误页面。

例如，默认错误页面是带有“404：未找到”之类的 HTML 响应。我正在为子域api.localhost:5000 设置一个类似 REST 的 API。我想做的是以某种方式告诉 Flask，如果您看到诸如 api.localhost:5000/* 之类的域并且您收到 404，则发回 jsonified 响应，否则继续发回 HTML 响应。

这是一个简单的例子：

from flask import abort, jsonify, Blueprint
api = Blueprint("api", __name__)

@api.route("/bad/route", subdomain="api")
def api_base():
    """Purposefly define a bad route and send back jsonified error response."""
    # Forcefully calling `abort` will generate a jsonified response
    abort(404)
    # However, if I didn't anticipate a bad path and didn't call `abort`, a
    # default HTML 404 page is returned, which is defined in the `error`
    # blueprint located elsewhere in the application.

@api.errorhandler(404)
def resource_not_found(e):
    return jsonify(error=str(e)), 404

如果我提出请求：

http://api.localhost:5000/bad/route

我会得到一个不错的 json 响应，否则像 http://api.localhost:5000/another/bad/route 这样的东西会返回一个 404 HTML 响应。

【问题讨论】：

标签： python python-3.x flask uwsgi flask-restful

【解决方案1】：

使用您自己的 process_response 创建一个自定义烧瓶类

工作示例：

import json
from flask import Flask, abort, jsonify, Blueprint, jsonify, make_response

api = Blueprint("api", __name__)

@api.route("/good")
def good_route():
    return app.make_response("Hello World")

@api.route("/bad/route")
def api_base():
    """Purposefly define a bad route and send back jsonified error response."""
    # Forcefully calling `abort` will generate a jsonified response
    abort(404)
    # However, if I didn't anticipate a bad path and didn't call `abort`, a
    # default HTML 404 page is returned, which is defined in the `error`
    # blueprint located elsewhere in the application.

@api.errorhandler(404)
def resource_not_found(e):
    return jsonify(error=str(e)), 404


class MyFlask(Flask):
    def process_response(self, response):
        #Every response will be processed here first
        if response.status_code == 404:
            # send a json response
            return make_response(jsonify({"error": "Route Not found"}), 404)
        return response

app = MyFlask("api")
app.register_blueprint(api)

测试它：

(venv) bhakta@blr:~/dev/flask$ curl -D headers -X GET http://api.localhost:5000/good
Hello World(venv) bhakta@blr:~/dev/flask$
(venv) bhakta@blr:~/dev/flask$
(venv) bhakta@blr:~/dev/flask$
(venv) bhakta@blr:~/dev/flask$ cat headers
HTTP/1.0 200 OK
Content-Type: text/html; charset=utf-8
Content-Length: 11
Server: Werkzeug/0.15.0 Python/3.6.8
Date: Sun, 01 Aug 2021 10:35:38 GMT

(venv) bhakta@blr:~/dev/flask$
(venv) bhakta@blr:~/dev/flask$
(venv) bhakta@blr:~/dev/flask$

(venv) bhakta@blr:~/dev/flask$ curl -D headers -X GET http://api.localhost:5000/bad
{"error":"Route Not found"}
(venv) bhakta@blr:~/dev/flask$
(venv) bhakta@blr:~/dev/flask$
(venv) bhakta@blr:~/dev/flask$ cat headers
HTTP/1.0 404 NOT FOUND
Content-Type: application/json
Content-Length: 28
Server: Werkzeug/0.15.0 Python/3.6.8
Date: Sun, 01 Aug 2021 10:35:43 GMT

【讨论】：