当用户不提交图片上传时，blob是否仍存储在blobstore中？

Question

我允许一次上传10张图片（直接上传到blob商店）。 在表单中，图像与文本相匹配。在

并非所有内容都需要图像，因此用户提交表单时，图像通常没有选定的图像文件。在

我希望只有blob会被上传到图片中（因为这是在开发服务器上发生的事情）。在

然而，当我看到一堆空的图片时，我看到了一堆空的图片：

Blob List > (application/octet-stream) 0 Bytes, 2012-08-14 17:11:54 AMIfv94Y7ie8cE84WZfEWGZw-NKJPE4iUaYn25zN1J-uftmoCESQoQFBimdiZr19suNBg_kUFW0P2frxIadmpd6LzPuFuA6o9UVq5UEqSvioXaBsDQeMwdJiH5gvh-8TtlZz8Rr1fRHHZd47zsiZpDiF1XsKa6A4aKTDvCnGEdMpW8lV6nlcFfU Blobs with this content type cannot be displayed.

我如何预防这些？这是我的代码：

class AdminHandler(webapp2.RequestHandler):
    #displays a form that includes content1, img1, content2, image2..
    def get(self):
        upload_url = blobstore.create_upload_url(self.uri_for('image-upload-handler'))
        template_values = {'page_name': 'admin', 'upload_url': upload_url}
        template = jinja_environment.get_template('admin.html')
        self.response.out.write(template.render(template_values))

class BlogPost(ndb.Model):
    date = ndb.DateProperty(required=True)
    title = ndb.StringProperty(required=True)
    blob_keys = ndb.BlobKeyProperty(repeated=True)
    content = ndb.TextProperty(repeated=True)
    content_order = ndb.StringProperty(repeated=True)

    @classmethod
    def get_blog_posts(cls):
        return cls.query().order(-cls.date)


class ImageUploadHandler(blobstore_handlers.BlobstoreUploadHandler):
    def post(self):
        password = self.request.get('password', None)
        if str(password).lower() == 'cyclist':
            day = self.request.get('day', None)
            month = self.request.get('month', None)
            year = self.request.get('year', None)

            day, month, year = map(int, (day, month, year))

            try:
                date = datetime(year, month, day)
                #date = datetime.today()
            except ValueError:
                date = datetime.today()

            title = self.request.get('title', None)

            blob_keys = [i.key() for i in self.get_uploads()]
            #assert(blob_keys)
            content = []
            content_order = []
            for i in range(1, 11):
                content_i = self.request.get("content{0}".format(i), None)
                if content_i:
                    content_i = cgi.escape(content_i)
                    content_i = "<br />".join(content_i.replace("\r\r", "\r").splitlines())

                    content.append(content_i)
                    content_order.append("content_next")

                img_i = self.request.get("img{0}".format(i), None)
                if img_i and not "Content-Length: 0" in str(img_i):
                    content_order.append("image_next")

            #assert(content)

            blog_post = BlogPost()
            blog_post.title = title
            blog_post.blob_keys = blob_keys
            blog_post.content = content
            blog_post.date = date
            blog_post.content_order = content_order
            blog_post.put()
            ok = True
            success = "success"
        else:
            ok = False
            success = "wrong password"



<form action="{{upload_url}}" enctype="multipart/form-data"  method="post">
    Date day e.g. 31: <input id='day' type="text" name="day" /><br />
    Date month e.g. 12: <input id='month' type="text" name="month" /><br />
    Date year e.g. 2012: <input id='year' type="text" name="year" /><br />

    Title: <input id="title" type="text" name="title" /><br />
    Content1: <br />
    <textarea id="styled2" name="content1"></textarea>
    <br />
    Image1:<input type="file" name="img1"/><br />
    ...<br />
    {% for i in range(2, 11) %}
    Content{{i}}: <br />
        <textarea id="styled" name="content{{i}}"></textarea>
    <br />
    Image{{i}}:<input type="file" name="img{{i}}"/><br />
    ...<br />
    {% endfor %}
    password: <input id="password" type="text" name="password" /><br />
    <input type="submit" value="Submit" /><br />
    <div id="error-box"></div>
</form>

注意：我上线时必须添加and not "Content-Length: 0" in str(img_i):，因为在开发服务器上它是一个空字符串，但在appengine上不是。在

Answer 1

这是一个known issue，我建议你给它加一个星。在

在修复之前，几乎可以选择在客户端捕获空的上载而不提交它们，或者在上载处理程序中从blobstore中删除长度为零的blob。在