Flask-sqlalchemy with Blueprints - RuntimeError: No application found. Either work inside a view function or push an application context

Question

有很多关于此的问题，但 none 其中使用的是 Flask 蓝图。

我正在尝试使用 sqlite3 查找设置 QuerySelectField。但是我得到错误：

RuntimeError: No application found. Either work inside a view function or push an application context.

这是我的应用程序结构：

我的init.py

from flask import Flask, render_template, current_app
from flask_mail import Mail
from flask_login import LoginManager
from flask_bootstrap import Bootstrap
from flask_ckeditor import CKEditor
from instance.config import app_config
from app.views.ticket import ticket as ticket_blueprint
from app.views.users import users as user_blueprint
from app.views.main import main as main_blueprint
from app.models import User, db

login_manager = LoginManager()

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


def register_blueprints_on_app(app):
    app.register_blueprint(user_blueprint)
    app.register_blueprint(ticket_blueprint)
    app.register_blueprint(main_blueprint)


def login_manager_init(app):
    login_manager.login_view = 'users.login'
    login_manager.init_app(app)


# associate id in the cookie with the User object
@login_manager.user_loader
def load_user(user_id):
    print(user_id)
    return User.query.get(user_id)


# application factory
def create_app(config):
    # create application instance
    app = Flask(__name__, instance_relative_config=True)
    app.register_error_handler(404, page_not_found)
    app.config.from_object(app_config[config])
    app.config.from_pyfile('config.py')

    Bootstrap(app)

    mail = Mail()
    mail.init_app(app)
    db.init_app(app)

    ckeditor = CKEditor()
    ckeditor.init_app(app)

    login_manager_init(app)
    register_blueprints_on_app(app)

    return app

这是有问题的 forms.py，它位于 ticket/views/

下

from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField, TextAreaField, FieldList, DateTimeField, SelectField
from wtforms_sqlalchemy.fields import QuerySelectField
from wtforms.fields.html5 import EmailField, TelField
from wtforms.validators import InputRequired, Email
from flask_ckeditor import CKEditorField
from app.models import User


def user_query():
    query = User.query()
    return query


class TicketForm(FlaskForm):
    requested_by = QuerySelectField(label='Requested by',
                                    query_factory=user_query(),
                                    allow_blank=False,
                                    get_label='fullname')
    department = SelectField(label='Department')
    phone = TelField(label='Phone')
    email = EmailField(label='Email', validators=[Email('Enter a valid email address')])
    short_desc = StringField(label='Short Description', validators=[InputRequired('Must enter a short description')])
    description = CKEditorField(label='Description')
    classification = StringField(label='Classification')
    priority = StringField(label='Priority')

    sla_respond_by = DateTimeField(label='Respond by', render_kw={'readonly': True})
    sla_resolve_by = DateTimeField(label='Resolve by', render_kw={'readonly': True})
    sla_status = StringField(label='SLA Status', render_kw={'readonly': True})

    related_tickets = FieldList(StringField(label='Ticker #'))
    client_journal = TextAreaField(label='Client Area')
    work_notes = TextAreaField(label='Work Notes')
    closed_at = DateTimeField(label='Closed')
    closed_by = StringField(label='Closed by')
    followed_by = StringField(label='Followed by')
    submit = SubmitField('Save')

问题部分是在运行时

 def user_query():
        query = User.query()
        return query

我收到错误。

这里的上下文是 ticket/view

下的路由文件

from flask import render_template
from app.views.ticket.forms import TicketForm
from flask_login import login_required
from . import ticket


@ticket.get('/ticket')
@ticket.put('/ticket')
@login_required
def ticket():
    form = TicketForm()
    return render_template('ticket.html', form=form)

并且在ticket/view/init.py

from flask import Blueprint

ticket = Blueprint('ticket', __name__, static_folder='static', template_folder='templates')

from . import routes

我在这里阅读了文档，但没有帮助。 https://flask-sqlalchemy.palletsprojects.com/en/2.x/contexts/

我不知道如何传递应用程序上下文，所以这个函数起作用了。

Answer 1

我通过在 QuerySelectfield 中不使用 query_factory 来解决这个问题。

我更改了字段声明：

class TicketForm(FlaskForm):
    requested_by = QuerySelectField(label='Requested by',
                                    query_factory=user_query(),
                                    allow_blank=False,
                                    get_label='full_name')

为此：

class TicketForm(FlaskForm):
    requested_by = QuerySelectField(label='Requested by',
                                    allow_blank=False,
                                    get_label='full_name')

(所以，刚刚删除了 query_factory=user_query(),)

我删除了这个：

def user_query():
        query = User.query()
        return query

然后将其添加到我的蓝图中的路线中：

@ticket.get('/ticket')
@ticket.put('/ticket')
@login_required
def ticket():
    form = TicketForm()

    form.requested_by.query = User.query.all()  # Added this

    print(current_app.app_context())
    return render_template('ticket.html', form=form)

我希望这对我正在努力的人有所帮助。我仍然想知道如何使用 query_factory 以另一种方式做到这一点，因为我确信有办法。所以如果有人知道请分享！

Flask-sqlalchemy with Blueprints - RuntimeError: No application found. Either work inside a view function or push an application context

Flask-sqlalchemy with Blueprints - RuntimeError: No application found. Either work inside a view function or push an application context

python

flask

flask-sqlalchemy