如何将数据发送到网页上的特定字段？

Question

我正在使用由其他人使用cherrypy创建的此网页。 我想在地图下方的四个纬度/经度输入框中显示 server.py 脚本中生成的数据值。 “左侧”输入字段在所附屏幕截图中突出显示。

当用户在地图上绘制矩形时，当前会填充四个输入字段，这些值是与矩形对应的最小/最大纬度/经度。 如果用户上传航点文件，程序将从文件而不是地图生成这些值。不幸的是，这个应用程序的原始创建者没有在最小/最大纬度/经度字段中显示文件生成的边界，我希望纠正这个缺陷。

这里是生成要显示的数据的server.py代码：

# -*- coding: utf-8 -*-
import os, sys
import shutil
import cherrypy
import shelve
import time
import traceback
import fcntl
from genshi.filters import HTMLFormFiller
from xcsoar.mapgen.server.job import Job, JobDescription
from xcsoar.mapgen.server import view
from xcsoar.mapgen.georect import GeoRect
from xcsoar.mapgen.waypoints.parser import parse_waypoint_file

#cherrypy.config.update({'log.screen': True})
cherrypy.config.update({
         'log.screen': True,  # Log to stdout
         'log.error_file': 'error.log',  # Log errors to a file
         'log.access_file': 'access.log'  # Log access to a file
     })



class Server(object):
    def __init__(self, dir_jobs):
        self.__dir_jobs = os.path.abspath(dir_jobs)

    def too_many_requests(self):
        db = None
        lock = None
        try:
            if not os.path.exists(self.__dir_jobs):
                os.makedirs(self.__dir_jobs)
            lock = open(os.path.join(self.__dir_jobs, "requests.db.lock"), "a")
            fcntl.flock(lock, fcntl.LOCK_EX)
            db = shelve.open(os.path.join(self.__dir_jobs, "requests.db"))
            for ip in list(db.keys()):
                times = db[ip]
                for t in times:
                    if time.time() - t > 3600:
                        times.remove(t)
                if len(times) == 0:
                    del db[ip]
                else:
                    db[ip] = times
            ip = cherrypy.request.remote.ip
            if ip in db:
                if len(db[ip]) >= 3:
                    return True
                times = db[ip]
                times.append(int(time.time()))
                db[ip] = times
            else:
                db[ip] = [int(time.time())]
            return False
        except Exception as e:
            print(("Error: {}".format(e)))
            traceback.print_exc(file=sys.stdout)
            return False
        finally:
            if lock != None:
                lock.close()
            if db != None:
                db.close()

    @cherrypy.expose
    @view.output("index.html")
    def index(self, **params):
        cherrypy.log('At the top of the index.html function, with params = %s' % params)
        if cherrypy.request.method != "POST":
            return view.render()

        name = params["name"].strip()
        cherrypy.log('params: name = %s, mail = %s, detail = %s' % (name, params["mail"], params["level_of_detail"]))

        if name == "":
            return view.render(error="No map name given!") | HTMLFormFiller(data=params)

        desc = JobDescription()
        desc.name = name
        desc.mail = params["mail"]
        desc.resolution = 3.0 if "highres" in params else 9.0
        desc.compressed = "compressed" in params
        desc.welt2000 = "welt2000" in params
        desc.level_of_detail = int(params["level_of_detail"])

        selection = params["selection"]
        waypoint_file = params["waypoint_file"]
        cherrypy.log('waypoint_file = %s, waypoint_filename = %s, selection = %s' % (waypoint_file.file, waypoint_file.filename, selection))
        cherrypy.log('waypoint_file = %s' % waypoint_file.file)

        #gfp added to determine 'waypoint_file' type
        # cherrypy.log('displaying lines from waypoint_file.file')
        # lines = waypoint_file.file.readlines()
        # for line in lines:
        #     cherrypy.log(line)


        if selection in ["waypoint", "waypoint_bounds"]:
            if not waypoint_file.file or not waypoint_file.filename:
                return view.render(error="No waypoint file uploaded.") | HTMLFormFiller(
                    data=params
                )

            try:
                filename = waypoint_file.filename.lower()
                cherrypy.log('in TRY block filename = %s' % filename)

                if not filename.endswith(".dat") and (
                    filename.endswith(".dat") or not filename.endswith(".cup")
                ):
                    raise RuntimeError(
                        "Waypoint file {} has an unsupported format.".format(
                            waypoint_file.filename
                        )
                    )
    
                # #241212 better way to write this boolean expression (filename already forced to lowercase)
                if not filename.endswith(".dat") and not filename.endswith(".cup"):
                    raise RuntimeError(
                        "Waypoint file {} has an unsupported format.".format(
                            waypoint_file.filename
                        )
                    )

                desc.bounds = parse_waypoint_file(
                    waypoint_file.filename, waypoint_file.file
                ).get_bounds()
                desc.waypoint_file = (
                    "waypoints.cup" if filename.endswith(".cup") else "waypoints.dat"
                )

                cherrypy.log(f'in server.py: {filename} bounds: left = {desc.bounds.left:.3f}, right: {desc.bounds.right:.3f}, top: {desc.bounds.top:.3f}, bot {desc.bounds.bottom:.3f}')
                return view.render(
                    error="Just after bounds display " + waypoint_file.filename
                ) | HTMLFormFiller(data=params)

            except:
                return view.render(
                    error="Unsupported waypoint file " + waypoint_file.filename
                ) | HTMLFormFiller(data=params)

        if selection in ["bounds", "waypoint_bounds"]:
            try:
                desc.bounds = GeoRect(
                    float(params["left"]),
                    float(params["right"]),
                    float(params["top"]),
                    float(params["bottom"]),
                )
            except:
                return view.render(error="Map bounds not set.") | HTMLFormFiller(
                    data=params
                )

        if desc.bounds.height() <= 0 or desc.bounds.width() <= 0:
            return view.render(error="Bounds are invalid.") | HTMLFormFiller(
                data=params
            )

        if desc.bounds.height() * desc.bounds.width() > 1000:
            return view.render(error="Selected area is too large.") | HTMLFormFiller(
                data=params
            )

        if self.too_many_requests():
            return view.render(
                error="You can generate only three maps per hour."
            ) | HTMLFormFiller(data=params)

        job = Job(self.__dir_jobs, desc)

        if desc.waypoint_file:
            waypoint_file.file.seek(0)
            cherrypy.log("In the 'desc.waypoint_file' routine")

            f = open(job.file_path(desc.waypoint_file), "w")
            try:
                shutil.copyfileobj(fsrc=waypoint_file.file, fdst=f, length=1024 * 64)
            finally:
                f.close()

        desc.download_url = "/download?uuid=" + job.uuid
        job.enqueue()
        raise cherrypy.HTTPRedirect("/status?uuid=" + job.uuid)

    @cherrypy.expose
    @view.output("status.html")
    def status(self, uuid):
        job = Job.find(self.__dir_jobs, uuid)
        if job is None:
            return view.render("error.html", error="Job not found!")
        status = job.status()
        if status == "Error":
            return view.render("error.html", error="Generation failed!")
        elif status == "Done":
            return view.render("done.html", name=job.description.name, uuid=uuid)
        return view.render(uuid=uuid, name=job.description.name, status=status)

    @cherrypy.expose
    def download(self, uuid):
        job = Job.find(self.__dir_jobs, uuid)
        if not job or job.status() != "Done":
            return self.status(uuid)
        return cherrypy.lib.static.serve_download(
            job.map_file(), job.description.name + ".xcm"
        )

特别是，以下片段实际上生成了要显示的四个数据值：

        desc.bounds = parse_waypoint_file(
            waypoint_file.filename, waypoint_file.file
        ).get_bounds()
        desc.waypoint_file = (
            "waypoints.cup" if filename.endswith(".cup") else "waypoints.dat"
        )

        cherrypy.log(f'in server.py: {filename} bounds: left = {desc.bounds.left:.3f}, right: {desc.bounds.right:.3f}, top: {desc.bounds.top:.3f}, bot {desc.bounds.bottom:.3f}')

我对Python 的能力还算勉强，但对cherrypy 和html 的能力却令人尴尬，所以请善待我。 我学习了许多 cherrypy 教程，但在找到我认为相关的内容之前就迷失了方向。

Answer 1

看起来您需要将此数据传递给

.render()

调用并修改 HTML 文件以在这些

value

标签中包含

<input>

属性。他们需要渲染通过

render()

调用传递到模板渲染引擎的数据，并通过上下文名称访问它们。你在 GitHub 或者其他地方有这个吗？其他模块中的代码可能会给您一些线索。