Question

我对flask_track_usage模块有疑问。我所有的蓝图都应包含Trackusage功能。不幸的是，我没有找到解决问题的方法。为什么不能简单地使用flask.current_app？

route.py

import datetime
from uuid import uuid4
from flask import Blueprint, session, render_template, url_for, flash, redirect, current_app, request, jsonify
from flask_template.main.utils import my_func
import os
import json
from flask_track_usage import TrackUsage
from flask_track_usage.storage.printer import PrintWriter
from flask_track_usage.storage.output import OutputWriter


main = Blueprint('main', __name__)

t = TrackUsage(current_app, [
    PrintWriter(),
    OutputWriter(transform=lambda s: "OUTPUT: " + str(s))
])


@t.include
@main.before_request
def session_management():
    now = datetime.datetime.now()
    session_lifetime = current_app.config['SESSION_DURATION']

    # Create session, if not already existing
    if session.get('session_ID') is None:
        # Initiate session, set a random UUID as Session ID
        session['session_ID'] = str(uuid4())
        session.permanent = True  # will expire after 30 minutes of inactivity
        session['timeout'] = False
        print(f'Initated session with ID:', session.get('session_ID'))

        return redirect(url_for('main.index'))

    else:
        try:
            last_active = session.get('last_active')
            delta = now - last_active
            if delta.seconds > 1740:
                print(f'Note: Session lifetime less than one minute. Expires in:',
                              session_lifetime - delta.seconds, 'sec')
            if delta.seconds > session_lifetime:
                session['last_active'] = now
                session['timeout'] = True
                print(f'Your session has expired after 30 minutes, you have been logged out (files are deleted).')

                return redirect(url_for('main.logout'))

        except:
            pass

    try:
        session['last_active'] = now
    except:
        pass


@main.route('/')
def index():
    return redirect(url_for('main.home'))


@main.route('/home')
def home():
    return render_template('home.html', title='home', subheader='Template Main Page')

__ init __。py

from flask import Flask
from flask_template.config import Config


def create_app(config_class=Config):

    app = Flask(__name__)
    app.config.from_object(Config)

    from flask_template.sample_extension.routes import sample_extension
    from flask_template.main.routes import main
    from flask_template.errors.handlers import errors

    app.register_blueprint(sample_extension)
    app.register_blueprint(main)
    app.register_blueprint(errors)

    return app

配置

import os
import json
from datetime import timedelta

with open(os.path.join(os.getcwd(), 'etc', 'app_config.json')) as config_file:
    config = json.load(config_file)


class Config:

    SECRET_KEY = config.get('SECRET_KEY')
    SESSION_DURATION = 1800  # 30 minutes for delete function
    PERMANENT_SESSION_LIFETIME = timedelta(minutes=30)  # session lifetime

    root_dir = os.path.join(os.path.realpath('.'), 'flask_template')

    # Path to template to illustrate download functionality
    TEMPLATE_FOLDER = os.path.join(root_dir, 'sample_extension', 'assets', 'template')
    TRACK_USAGE_USE_FREEGEOIP = False
    TRACK_USAGE_INCLUDE_OR_EXCLUDE_VIEWS = 'include'

run.py

from flask_template import create_app

from flask_track_usage import TrackUsage
from flask_track_usage.storage.printer import PrintWriter
from flask_track_usage.storage.output import OutputWriter

app = create_app()

if __name__ == '__main__':

    app.run(ssl_context=('******'),
            host='0.0.0.0',
            port=5000,
            debug=True)

错误

RuntimeError：在应用程序上下文之外工作。

Answer 1

有几个全局Flask变量，例如current_app和g，只有在应用程序运行时才能访问（有关Flask Application Context文档条目的更多信息）。在应用程序上下文之外使用它们会引发RuntimeError。

您可以在 routes.py 模块中不带参数的情况下实例化TrackUsage：

track_usage = TrackUsage()


@track_usage.include
@main.before_request
def session_management():
    ...

然后您可以将其导入到 __ init __。py 模块中并应用于您的应用程序实例：

from flask import Flask
from flask_template.config import Config
from flask_track_usage.storage.printer import PrintWriter
from flask_track_usage.storage.output import OutputWriter


def create_app(config_class=Config):

    app = Flask(__name__)
    app.config.from_object(Config)

    from flask_template.sample_extension.routes import sample_extension, track_usage
    from flask_template.main.routes import main
    from flask_template.errors.handlers import errors

    track_usage.init_app(app, [
        PrintWriter(),
        OutputWriter(transform=lambda s: "OUTPUT: " + str(s)),
    ])

    app.register_blueprint(sample_extension)
    app.register_blueprint(main)
    app.register_blueprint(errors)

    return app

我在Flask-Track-Usage documentation中找不到此解决方案，但它是Flask扩展的常用接口。它允许实例化一个模块中的扩展并将其连接到主模块中的Flask应用程序。

将烧瓶跟踪用法与对象的蓝图和配置一起使用

1 个答案: