baseimage-tutorial-framework/src/event_handlers/source_code_event_handler.py

import json
from shutil import copy, rmtree, copytree
from os.path import splitext
import xmlrpc.client

from config import SUPERVISOR_HTTP_URI, LOGIN_APP_DIR
from event_handler_base import EventHandlerBase


class SourceCodeEventHandler(EventHandlerBase):
    def __init__(self, anchor, filename, process_name=None, zmq_context=None):
        super().__init__(anchor, zmq_context)
        self.working_directory = LOGIN_APP_DIR
        self.filename = filename
        self.language = map_file_extension_to_language(filename)
        self.process_name = process_name or splitext(filename)[0]

        server = xmlrpc.client.ServerProxy(SUPERVISOR_HTTP_URI)
        self.supervisor = server.supervisor

        self.file = self.create_initial_state()

    def handle_event(self, anchor, data_json):
        data = data_json['data']
        if anchor == b'reset':
            self.file = self.create_initial_state(process_is_running=True)
        if data['command'] == 'read':
            with open(self.file, 'r') as ifile:
                content = ifile.read()
            data_json['data'] = {
                'filename': self.filename,
                'content': content,
                'language': self.language
            }
            return data_json
        elif data['command'] == 'write':
            with open(self.file, 'w') as ofile:
                ofile.write(data['content'])
            self.supervisor.stopProcess(self.process_name)
            self.supervisor.startProcess(self.process_name)
            return None

    def create_initial_state(self, process_is_running=False):
        if process_is_running:
            self.supervisor.stopProcess(self.process_name)

        rmtree(self.working_directory, ignore_errors=True)
        copytree('source_code_server/', self.working_directory)
        file = copy(self.filename, self.working_directory)

        self.supervisor.startProcess(self.process_name)

        return file


def map_file_extension_to_language(filename):
    language_map = {
        # TODO: extend, maybe auto-generate???
        '.py': 'python',
        '.js': 'javascript'
    }
    _, extension = splitext(filename)
    return language_map[extension]