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Javascript 如何将AJAX与Google App Engine（Python）结合使用

javascript ajax google-app-engine python-2.7

Javascript 如何将AJAX与Google App Engine（Python）结合使用,javascript,ajax,google-app-engine,python-2.7,app-engine-ndb,Javascript,Ajax,Google App Engine,Python 2.7,App Engine Ndb,我对AJAX完全是新手。我熟悉HTML/CSS、jQuery以及GAE和Python的初学者 为了理解AJAX是如何工作的，我想知道在下面的示例中如何使用AJAX（实际代码）。让我们使用一个类似reddit的例子，其中投票上升/下降是ajaxified的： 以下是故事类型： class Story(ndb.Model): title = ndb.StringProperty(required = True) vote_count = ndb.IntegerProperty(def

我对AJAX完全是新手。我熟悉HTML/CSS、jQuery以及GAE和Python的初学者

为了理解AJAX是如何工作的，我想知道在下面的示例中如何使用AJAX（实际代码）。让我们使用一个类似reddit的例子，其中投票上升/下降是ajaxified的：

以下是故事类型：

class Story(ndb.Model):
    title = ndb.StringProperty(required = True)
    vote_count = ndb.IntegerProperty(default = 0)
HTML将如下所示：

<h2>{{story.title}}</h2>
<div>
    {{story.vote_count}} | <a href="#">Vote Up Story</a>
</div>

{{story.title}
{{故事.投票}}
AJAX如何适应这里

好的，先生，我们开始。。。一个简单的应用程序，只有一个故事和无限的选票…；-）

app.yaml

application: anotherappname
version: 1
runtime: python27
api_version: 1
threadsafe: true

default_expiration: "0d 0h 5m"

libraries:
- name: jinja2
  version: latest

- name: webapp2
  version: latest

handlers:
- url: .*
  script: main.app

import logging
from controllers import server
from config import config
import webapp2


app = webapp2.WSGIApplication([
        # Essential handlers
        ('/', server.RootPage),
        ('/vote/', server.VoteHandler)
    ],debug=True, config=config.config)


# Extra Hanlder like 404 500 etc
def handle_404(request, response, exception):
    logging.exception(exception)
    response.write('Oops! Naughty Mr. Jiggles (This is a 404)')
    response.set_status(404)

app.error_handlers[404] = handle_404

from google.appengine.ext import ndb


class Story(ndb.Model):
    title = ndb.StringProperty(required=True)
    vote_count = ndb.IntegerProperty(default = 0)

import os
import re
import logging
import config
import json

import webapp2
import jinja2

from google.appengine.ext import ndb
from models.story import Story


class RootPage(webapp2.RequestHandler):
    def get(self):
        story = Story.get_or_insert('Some id or so', title='A voting story again...')
        jinja_environment = self.jinja_environment
        template = jinja_environment.get_template("/index.html")
        self.response.out.write(template.render({'story': story}))


    @property
    def jinja_environment(self):
        jinja_environment = jinja2.Environment(
            loader=jinja2.FileSystemLoader(
                os.path.join(os.path.dirname(__file__),
                             '../views'
                ))
        )
        return jinja_environment


class VoteHandler(webapp2.RequestHandler):
    def post(self):
        logging.info(self.request.body)
        data = json.loads(self.request.body)
        story = ndb.Key(Story, data['storyKey']).get()
        story.vote_count += 1
        story.put()
        self.response.out.write(json.dumps(({'story': story.to_dict()})))

<!DOCTYPE html>
<html>
    <head>
        <base href="/">
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
    </head>
    <body>
        <h2>{{story.title}}</h2>
        <div>
            <span class="voteCount">{{story.vote_count}}</span>  | <a href="javascript:VoteUp('{{story.key.id()}}');" >Vote Up Story</a>
        </div>
        <script>
            function VoteUp(storyKey){
                $.ajax({
                  type: "POST",
                  url: "/vote/",
                  dataType: 'json',
                  data: JSON.stringify({ "storyKey": storyKey})
                })
                .done(function( data ) { // check why I use done
                    alert( "Vote Cast!!! Count is : " + data['story']['vote_count'] );
                    $('.voteCount').text(data['story']['vote_count']);
                });
            };
        </script>
    </body>
</html>

main.py

application: anotherappname
version: 1
runtime: python27
api_version: 1
threadsafe: true

default_expiration: "0d 0h 5m"

libraries:
- name: jinja2
  version: latest

- name: webapp2
  version: latest

handlers:
- url: .*
  script: main.app

import logging
from controllers import server
from config import config
import webapp2


app = webapp2.WSGIApplication([
        # Essential handlers
        ('/', server.RootPage),
        ('/vote/', server.VoteHandler)
    ],debug=True, config=config.config)


# Extra Hanlder like 404 500 etc
def handle_404(request, response, exception):
    logging.exception(exception)
    response.write('Oops! Naughty Mr. Jiggles (This is a 404)')
    response.set_status(404)

app.error_handlers[404] = handle_404

from google.appengine.ext import ndb


class Story(ndb.Model):
    title = ndb.StringProperty(required=True)
    vote_count = ndb.IntegerProperty(default = 0)

import os
import re
import logging
import config
import json

import webapp2
import jinja2

from google.appengine.ext import ndb
from models.story import Story


class RootPage(webapp2.RequestHandler):
    def get(self):
        story = Story.get_or_insert('Some id or so', title='A voting story again...')
        jinja_environment = self.jinja_environment
        template = jinja_environment.get_template("/index.html")
        self.response.out.write(template.render({'story': story}))


    @property
    def jinja_environment(self):
        jinja_environment = jinja2.Environment(
            loader=jinja2.FileSystemLoader(
                os.path.join(os.path.dirname(__file__),
                             '../views'
                ))
        )
        return jinja_environment


class VoteHandler(webapp2.RequestHandler):
    def post(self):
        logging.info(self.request.body)
        data = json.loads(self.request.body)
        story = ndb.Key(Story, data['storyKey']).get()
        story.vote_count += 1
        story.put()
        self.response.out.write(json.dumps(({'story': story.to_dict()})))

<!DOCTYPE html>
<html>
    <head>
        <base href="/">
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
    </head>
    <body>
        <h2>{{story.title}}</h2>
        <div>
            <span class="voteCount">{{story.vote_count}}</span>  | <a href="javascript:VoteUp('{{story.key.id()}}');" >Vote Up Story</a>
        </div>
        <script>
            function VoteUp(storyKey){
                $.ajax({
                  type: "POST",
                  url: "/vote/",
                  dataType: 'json',
                  data: JSON.stringify({ "storyKey": storyKey})
                })
                .done(function( data ) { // check why I use done
                    alert( "Vote Cast!!! Count is : " + data['story']['vote_count'] );
                    $('.voteCount').text(data['story']['vote_count']);
                });
            };
        </script>
    </body>
</html>

models/story.py

application: anotherappname
version: 1
runtime: python27
api_version: 1
threadsafe: true

default_expiration: "0d 0h 5m"

libraries:
- name: jinja2
  version: latest

- name: webapp2
  version: latest

handlers:
- url: .*
  script: main.app

import logging
from controllers import server
from config import config
import webapp2


app = webapp2.WSGIApplication([
        # Essential handlers
        ('/', server.RootPage),
        ('/vote/', server.VoteHandler)
    ],debug=True, config=config.config)


# Extra Hanlder like 404 500 etc
def handle_404(request, response, exception):
    logging.exception(exception)
    response.write('Oops! Naughty Mr. Jiggles (This is a 404)')
    response.set_status(404)

app.error_handlers[404] = handle_404

from google.appengine.ext import ndb


class Story(ndb.Model):
    title = ndb.StringProperty(required=True)
    vote_count = ndb.IntegerProperty(default = 0)

import os
import re
import logging
import config
import json

import webapp2
import jinja2

from google.appengine.ext import ndb
from models.story import Story


class RootPage(webapp2.RequestHandler):
    def get(self):
        story = Story.get_or_insert('Some id or so', title='A voting story again...')
        jinja_environment = self.jinja_environment
        template = jinja_environment.get_template("/index.html")
        self.response.out.write(template.render({'story': story}))


    @property
    def jinja_environment(self):
        jinja_environment = jinja2.Environment(
            loader=jinja2.FileSystemLoader(
                os.path.join(os.path.dirname(__file__),
                             '../views'
                ))
        )
        return jinja_environment


class VoteHandler(webapp2.RequestHandler):
    def post(self):
        logging.info(self.request.body)
        data = json.loads(self.request.body)
        story = ndb.Key(Story, data['storyKey']).get()
        story.vote_count += 1
        story.put()
        self.response.out.write(json.dumps(({'story': story.to_dict()})))

<!DOCTYPE html>
<html>
    <head>
        <base href="/">
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
    </head>
    <body>
        <h2>{{story.title}}</h2>
        <div>
            <span class="voteCount">{{story.vote_count}}</span>  | <a href="javascript:VoteUp('{{story.key.id()}}');" >Vote Up Story</a>
        </div>
        <script>
            function VoteUp(storyKey){
                $.ajax({
                  type: "POST",
                  url: "/vote/",
                  dataType: 'json',
                  data: JSON.stringify({ "storyKey": storyKey})
                })
                .done(function( data ) { // check why I use done
                    alert( "Vote Cast!!! Count is : " + data['story']['vote_count'] );
                    $('.voteCount').text(data['story']['vote_count']);
                });
            };
        </script>
    </body>
</html>

控制器/server.py

application: anotherappname
version: 1
runtime: python27
api_version: 1
threadsafe: true

default_expiration: "0d 0h 5m"

libraries:
- name: jinja2
  version: latest

- name: webapp2
  version: latest

handlers:
- url: .*
  script: main.app

import logging
from controllers import server
from config import config
import webapp2


app = webapp2.WSGIApplication([
        # Essential handlers
        ('/', server.RootPage),
        ('/vote/', server.VoteHandler)
    ],debug=True, config=config.config)


# Extra Hanlder like 404 500 etc
def handle_404(request, response, exception):
    logging.exception(exception)
    response.write('Oops! Naughty Mr. Jiggles (This is a 404)')
    response.set_status(404)

app.error_handlers[404] = handle_404

from google.appengine.ext import ndb


class Story(ndb.Model):
    title = ndb.StringProperty(required=True)
    vote_count = ndb.IntegerProperty(default = 0)

import os
import re
import logging
import config
import json

import webapp2
import jinja2

from google.appengine.ext import ndb
from models.story import Story


class RootPage(webapp2.RequestHandler):
    def get(self):
        story = Story.get_or_insert('Some id or so', title='A voting story again...')
        jinja_environment = self.jinja_environment
        template = jinja_environment.get_template("/index.html")
        self.response.out.write(template.render({'story': story}))


    @property
    def jinja_environment(self):
        jinja_environment = jinja2.Environment(
            loader=jinja2.FileSystemLoader(
                os.path.join(os.path.dirname(__file__),
                             '../views'
                ))
        )
        return jinja_environment


class VoteHandler(webapp2.RequestHandler):
    def post(self):
        logging.info(self.request.body)
        data = json.loads(self.request.body)
        story = ndb.Key(Story, data['storyKey']).get()
        story.vote_count += 1
        story.put()
        self.response.out.write(json.dumps(({'story': story.to_dict()})))

<!DOCTYPE html>
<html>
    <head>
        <base href="/">
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
    </head>
    <body>
        <h2>{{story.title}}</h2>
        <div>
            <span class="voteCount">{{story.vote_count}}</span>  | <a href="javascript:VoteUp('{{story.key.id()}}');" >Vote Up Story</a>
        </div>
        <script>
            function VoteUp(storyKey){
                $.ajax({
                  type: "POST",
                  url: "/vote/",
                  dataType: 'json',
                  data: JSON.stringify({ "storyKey": storyKey})
                })
                .done(function( data ) { // check why I use done
                    alert( "Vote Cast!!! Count is : " + data['story']['vote_count'] );
                    $('.voteCount').text(data['story']['vote_count']);
                });
            };
        </script>
    </body>
</html>
最后

视图/index.html

application: anotherappname
version: 1
runtime: python27
api_version: 1
threadsafe: true

default_expiration: "0d 0h 5m"

libraries:
- name: jinja2
  version: latest

- name: webapp2
  version: latest

handlers:
- url: .*
  script: main.app

import logging
from controllers import server
from config import config
import webapp2


app = webapp2.WSGIApplication([
        # Essential handlers
        ('/', server.RootPage),
        ('/vote/', server.VoteHandler)
    ],debug=True, config=config.config)


# Extra Hanlder like 404 500 etc
def handle_404(request, response, exception):
    logging.exception(exception)
    response.write('Oops! Naughty Mr. Jiggles (This is a 404)')
    response.set_status(404)

app.error_handlers[404] = handle_404

from google.appengine.ext import ndb


class Story(ndb.Model):
    title = ndb.StringProperty(required=True)
    vote_count = ndb.IntegerProperty(default = 0)

import os
import re
import logging
import config
import json

import webapp2
import jinja2

from google.appengine.ext import ndb
from models.story import Story


class RootPage(webapp2.RequestHandler):
    def get(self):
        story = Story.get_or_insert('Some id or so', title='A voting story again...')
        jinja_environment = self.jinja_environment
        template = jinja_environment.get_template("/index.html")
        self.response.out.write(template.render({'story': story}))


    @property
    def jinja_environment(self):
        jinja_environment = jinja2.Environment(
            loader=jinja2.FileSystemLoader(
                os.path.join(os.path.dirname(__file__),
                             '../views'
                ))
        )
        return jinja_environment


class VoteHandler(webapp2.RequestHandler):
    def post(self):
        logging.info(self.request.body)
        data = json.loads(self.request.body)
        story = ndb.Key(Story, data['storyKey']).get()
        story.vote_count += 1
        story.put()
        self.response.out.write(json.dumps(({'story': story.to_dict()})))

<!DOCTYPE html>
<html>
    <head>
        <base href="/">
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
    </head>
    <body>
        <h2>{{story.title}}</h2>
        <div>
            <span class="voteCount">{{story.vote_count}}</span>  | <a href="javascript:VoteUp('{{story.key.id()}}');" >Vote Up Story</a>
        </div>
        <script>
            function VoteUp(storyKey){
                $.ajax({
                  type: "POST",
                  url: "/vote/",
                  dataType: 'json',
                  data: JSON.stringify({ "storyKey": storyKey})
                })
                .done(function( data ) { // check why I use done
                    alert( "Vote Cast!!! Count is : " + data['story']['vote_count'] );
                    $('.voteCount').text(data['story']['vote_count']);
                });
            };
        </script>
    </body>
</html>


{{story.title}
{{故事.投票}}
函数VoteUp（故事键）{
$.ajax({
类型：“POST”，
url:“/vote/”，
数据类型：“json”，
数据：JSON.stringify（{“storyKey”：storyKey}）
})
.done（函数（数据）{//检查为什么使用done
警告（“投票！！！计数为：+data['story']['Vote_Count']）；
$（'.voteCount'）.text（数据['story']['vote_count']）；
});
};
组装，阅读，足够简单，然后运行。如果您需要一个工作的git示例，只需注释即可

（来自评论）

这里是GitHub上的一个小web应用程序，用于测试如何使用AJAX、Python和Google app Engine处理HTML表单提交中的错误消息。这将为我们提供一个起点，看看这三项技术是如何融合在一起的。您可以在上测试此“应用程序”

以下是它在客户端的工作方式：

  • 这用于：

  • jQuery
    .ajax（）
    方法处理请求，而
    .done（）
    方法最终将处理从服务器获得的响应

在服务器端：

  • main.py
    文件使用我们的
    AjaxHandler
    处理业务的服务器端，它继承自GAE内置类
    webapp2.RequestHandler

  • 在这个类中，
    post
    方法处理AJAX请求：

    def post(self):
    data = json.loads(self.request.body)
    username = data["name"]

    if not re.match(r"^[a-zA-Z0-9_-]{3,20}$", username):
        if len(username) < 3:
            message = "Your name must be at least 3 characters long."
        else:
            message = "Allowed characters are \
                       a-z, A-Z, 0-9, underscores \
                       and hyphens."
    else:
        message = "Congrats!"

    self.response.write(json.dumps({"message": message}))

    def post（self）：
data=json.load（self.request.body）
用户名=数据[“名称”]
如果没有重新匹配（r“^[a-zA-Z0-9_-]{3,20}$”，用户名）：
如果len（用户名）<3：
message=“您的姓名长度必须至少为3个字符。”
其他：
message=“允许使用的字符是\
a-z，a-z，0-9，下划线\
还有连字符。”
其他：
message=“恭喜！”
self.response.write（json.dumps（{“message”：message}））
  • 基本上，方便的
    json
    模块提供了两个关键的Python成分

    • json.load
      处理浏览器发送到服务器的数据
    • json.dumps
      处理服务器响应浏览器请求发送的数据
    • json.loads
      的
      self.request.body
      参数是流程中使用的唯一不太常见的GAE，因为它特定于任务。顾名思义，它从客户端发送的Ajax请求中获取主体
@haopei很抱歉我忘了你。干得好。我希望你能成为明星；-）再次感谢你，吉米·凯恩。你能简单地解释一下self.request.body的作用吗？我在webapp和appengine文档上进行了搜索，结果发现很少。在文档中几乎没有对它的定义。谢谢。@haopei检查一下这个。那里有记录。。。如果需要更多帮助，请提及。@haopei Datetime属性不可json序列化。尝试排除如下属性：
story.to_dict（exclude='my\u datetime'）
，然后将其转换并附加到dict。在此处检查to_dict以及如何使用它。此外，约会时间也是一种痛苦。如果您需要进一步的帮助，请在这里再次提及，我将尝试添加datetime序列化技术