Flask register_blueprint错误(Python)

Question

我在Flask上有一个项目.当我在我的Flask应用程序中包含Blueprint时,我有错误.代码来自Miguel Grinberg关于Flask的书.

项目树:

.
??? app
?   ??? __init__.py
?   ??? main
?   ?   ??? errors.py
?   ?   ??? __init__.py
?   ?   ??? views.py
?   ??? static
?   ?   ??? static_files
?   ??? templates
?       ??? html_files
??? config.py
??? manage.py

app/__ init__.py中的 create_app()

def create_app(config_name):
    app = Flask(__name__)
    app.config.from_object(config[config_name])
    config[config_name].init_app(app)
    bootstrap.init_app(app)
    db.init_app(app)

    from .main import main as main_blueprint
    app.register_blueprint(main_blueprint)   

    return app

列出app/main/__ init__.py

from flask import Blueprint

main = Blueprint('main', __name__)

from . import views, errors

乘客行过程输出

Traceback (most recent call last):
  File "/opt/passenger/passenger-4.0.57/helper-scripts/wsgi-loader.py", line 320, in <module>
    app_module = load_app()
  File "/opt/passenger/passenger-4.0.57/helper-scripts/wsgi-loader.py", line 61, in load_app
    return imp.load_source('passenger_wsgi', startup_file)
  File "/home/m/mallts/dev.wget-studio.ru/myenv/lib/python3.4/imp.py", line 171, in load_source
    module = methods.load()
  File "<frozen importlib._bootstrap>", line 1220, in load
  File "<frozen importlib._bootstrap>", line 1200, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1129, in _exec
  File "<frozen importlib._bootstrap>", line 1471, in exec_module
  File "<frozen importlib._bootstrap>", line 321, in _call_with_frames_removed
  File "passenger_wsgi.py", line 16, in <module>
    from manage import app as application
  File "/home/m/mallts/dev.wget-studio.ru/fikls/manage.py", line 7, in <module>
    app = create_app('default') #(os.getenv('FLASK_CONFIG') or 'default')
  File "/home/m/mallts/dev.wget-studio.ru/fikls/app/__init__.py", line 19, in create_app
    app.register_blueprint(main_blueprint)   
  File "/home/m/mallts/dev.wget-studio.ru/myenv/lib/python3.4/site-packages/flask/app.py", line 62, in wrapper_func
    return f(self, *args, **kwargs)
  File "/home/m/mallts/dev.wget-studio.ru/myenv/lib/python3.4/site-packages/flask/app.py", line 889, in register_blueprint
    blueprint.register(self, options, first_registration)
  File "/home/m/mallts/dev.wget-studio.ru/myenv/lib/python3.4/site-packages/flask/blueprints.py", line 153, in register
    deferred(state)
  File "/home/m/mallts/dev.wget-studio.ru/myenv/lib/python3.4/site-packages/flask/blueprints.py", line 128, in wrapper
    func(state)
  File "/home/m/mallts/dev.wget-studio.ru/myenv/lib/python3.4/site-packages/flask/blueprints.py", line 399, in <lambda>
    self.name, code_or_exception, f))
  File "/home/m/mallts/dev.wget-studio.ru/myenv/lib/python3.4/site-packages/flask/app.py", line 62, in wrapper_func
    return f(self, *args, **kwargs)
  File "/home/m/mallts/dev.wget-studio.ru/myenv/lib/python3.4/site-packages/flask/app.py", line 1090, in _register_error_handler
    'It is currently not possible to register a 500 internal ' \
AssertionError: It is currently not possible to register a 500 internal server error on a per-blueprint level.

我的app/main/errors.py

from flask import render_template
from . import main 

@main.errorhandler(404)
def page_not_found(e):
    return render_template('404.html'), 404

@main.errorhandler(500)
def internal_server_error(e):
    return render_template('500.html'), 500

我的app/main/views.py

from flask import render_template, url_for, session, redirect
from . import main 

@main.route('/')
def index():
    return render_template('index.html')

Answer 1

我刚刚与另一个我重构使用蓝图的应用程序遇到了同样的问题.不需要解决方法,因为Flask为这种情况提供了一个装饰器:app_errorhandler.它的工作方式与errorhandler为整个应用程序注册错误路径完全相同,但它适用于蓝图.像这样:

from flask import render_template
from . import main 

@main.app_errorhandler(404)
def page_not_found(e):
    return render_template('404.html'), 404

@main.app_errorhandler(500)
def internal_server_error(e):
    return render_template('500.html'), 500

格林伯格的书,Flask Web Development--一本优秀的读物 - 使用这个装饰器来记录main蓝图上的错误页面.您可以在此处查看配套代码.我一开始也想念它.:P

Answer 2

您无法在蓝图上创建500处理程序.

https://www.bountysource.com/issues/1400879-can-not-register-a-500-error-handler-for-blueprint

您必须在主应用程序上执行此操作.我觉得你的痛苦,因为你有一个app工厂,app/__ init__.py中没有路由 .

我通常在我的应用工厂模块中做这样的事情来处理这个缺点:

def register_errorhandlers(app):
    def render_error(error):
        error_code = getattr(error, 'code', 500)
        return render_template("{0}.html".format(error_code)), error_code

    for errcode in [500]:
        app.errorhandler(errcode)(render_error)
    return None

在create_app(config_name),app工厂方法,我称之为:

register_errorhandlers(app)