Question

我一直收到内部服务器错误 - 'BadValueError：属性内容是必需的。当我将blog_table传递给模板进行渲染时，似乎就会发生这种情况。这是代码：

main.py：

import os
import webapp2
import jinja2

from google.appengine.ext import db

jinja_env = jinja2.Environment(loader = jinja2.FileSystemLoader(os.path.join(os.path.dirname(__file__),'templates')), autoescape = True)

class Handler(webapp2.RequestHandler):
    def write(self,*a,**kw):
        self.response.out.write(*a,**kw)

    def render_str(self,template,**params):
        t = jinja_env.get_template(template)
        return t.render(params)

    def render(self,template,**kw):
        self.write(self.render_str(template,**kw))

class Blog(db.Model):
    subject = db.StringProperty(required = True)
    content = db.TextProperty(required = True)
    created = db.DateTimeProperty(auto_now_add = True)

class MainPage(Handler):
    def render_front(self, subject="", content="", error=""):
        blog_table = db.GqlQuery("SELECT * FROM Blog ORDER BY created DESC")
        self.render("blog.html",subject = subject,content = content,error = error,blog_table = blog_table)

    def get(self):
        self.render_front()

    def post(self):
        subject = self.request.get("subject")
        content = self.request.get("content")

        if subject and content:
            b = Blog(subject = subject, content = content)
            b.put()
            self.redirect("/")

        else:
            error = "we need both a subject and some content"
            self.render_front(subject,content,error)

app = webapp2.WSGIApplication([('/', MainPage)],debug=True)

HTML：

<!DOCTYPE html>

<html>
    <head>
        <title>Blog</title>
    </head>
    <body>
        <h1>Blog</h1>

        <form method="post">
            <label>
                <div>Subject</div>
                <input type="text" name="subject" value="{{subject}}">
            </label>
            <label>
                <div>Content</div>
                <textarea name="content" value="{{content}}"></textarea>
            </label>
            <div class="error">{{error}}</div>
            <input type="submit">
        </form>

        <hr>
    {% for post in blog_table %}
        <div class="post">
            <div class="subject">{{post.subject}}</div>
            <pre class="content">{{post.content}}</pre>
        </div>
    {% endfor %}

    </body>
</html>

要查看错误，请转到http://udacity-cs253-a31.appspot.com/

感谢。

Answer 1

这只是猜测 - 更改了您的Blog模型并最近添加了“内容”属性。

您的数据存储区中存在一些没有内容的Blog模型的旧实例。如果您尝试加载这些，您的代码将失败。如果您使用内容加载博客实例，一切都很好。

您必须浏览数据存储区并确保博客的所有实例都有内容。

内部服务器错误 - Google App Server（需要属性内容）

1 个答案: