PyCS/pycs/frontend/endpoints/labels/RemoveLabel.py

from flask import request, abort, make_response
from flask.views import View

from pycs import db
from pycs.database.Project import Project
from pycs.frontend.notifications.NotificationManager import NotificationManager


class RemoveLabel(View):
    """
    remove a label from database
    """
    # pylint: disable=arguments-differ
    methods = ['POST']

    def __init__(self, nm: NotificationManager):
        # pylint: disable=invalid-name
        self.nm = nm

    def dispatch_request(self, project_id: int, label_id: int):
        # extract request data
        data = request.get_json(force=True)

        if 'remove' not in data or data['remove'] is not True:
            abort(400)

        # find project
        project = Project.query.get(project_id)
        if project is None:
            abort(404)

        # find label
        label = project.label(label_id)
        if label is None:
            abort(404)

        # find children
        children = label.children

        # start transaction
        with db.session.begin_nested():
            # remove children's parent entry
            for child in children:
                child.set_parent(None)
                self.nm.edit_label(child.id)

            # remove label
            label.remove()
            self.nm.remove_label(label.serialize())

        # return success response
        return make_response()