使用来自对象的蓝图和配置的烧瓶跟踪用法

Question

我有一个关于 flask_track_usage 模块的问题。我所有的蓝图都应该包含 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，只能在应用程序处于运行时访问（有关它们的更多信息，请参见 Flask Application Context文档输入）。在应用程序上下文之外使用它们会引发 RuntimeError.

您可以在 routes.py 模块中不带参数实例化 TrackUsage：

track_usage = TrackUsage()


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

然后你可以将它导入你的__init__.py模块并应用到你的应用程序实例：

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

我没有在 Flask-Track-Usage documentation 中找到这个解决方案，但它是 Flask 扩展的通用接口。它允许在一个模块中实例化一个扩展并将其连接到主模块中的 Flask 应用程序。

使用来自对象的蓝图和配置的烧瓶跟踪用法

Using flask track usage with blueprint and config from object

python

blueprint

flask