Flask会话成员不会持续请求 [英] Flask session member not persisting across requests

问题描述

我正在写一个快速的应用程序来查看一个巨大的XML文件，其中有一些AJAX风格的调用 viewgroup 。我的问题是 session ['groups'] 不能持续。我有一些只有4个成员的旧数组卡在某处（cookie？..）。当 view 被调用时，该值是存在的。然后，我用最近打开的包含20多个成员的xml文件中的信息覆盖该会话成员。但是，当调用 viewgroup 时，会话变量已经恢复到旧值，只有4个成员在数组中！

输出代码。注意3 sessionStatus（）调用

  def sessionStatus b $ b printsession =+ str（len（session ['groups']））
 $ b @ app.route（'/'）
 def index（） ：
 cams = [file.lower（）。endswith（'xml'）] 
返回render_template（'index.html'，cam_files =凸轮）
 
 @ app.route（'/ view /< xmlfile>'）
 def view（xmlfile）：
 path ='xml /'+ secure_filename（xmlfile） 
 print'opening'+ path 
 xmlf = open（path，'r'）
 tree = etree.parse（xmlf）$ b $ root root = tree.getroot（）$ b $如果（p.search（g.tag）不是None）和（g .group'）
 groups = [] 
， attrib ['Comment']！='Root'）：
 groups.append（Group（g.attrib ['Comment']））
 sessionStatus（）
 session ['groups'] =组
 sessionStatus（）
返回render_tem （'view.html'，xml = xmlfile，groups = groups）
 
 @ app.route（'/ viewgroup /< name>）
 def viewGroup（name）：
 groups = session ['groups'] 
 sessionStatus（）
如果groups是None或len（groups）== 0：
抛出Exception（'invalid group name'）
 groups_filtered = [g for g in groups if g.name == name] 
 if len（groups_filtered）！= 1：
异常（'invalid group name'，groups_filtered）
 group = groups_filtered [0] 
 prop_names = [p在group.properties中的p.name] 
返回prop_names 
  

输出

 打开xml / d.xml 
 session中的组数量= 5 
＃group＃session $ 57 
 127.0.0.1  -   -  [17 / Aug / 2011 17:27:29]GET /view/d.xml HTTP / 1.1200  -  
 127.0.0.1  -   -  [17 / Aug / 2011 17:27:29]GET /static/ivtl.css HTTP / 1.1304  -  
 127.0.0.1  -   -  [17 / Aug / 2011 17:27： 29]GET /static/jquery.js HTTP / 1.1304  -  
 127.0。 0.1  -   -  [17 / Aug / 2011 17:27:29]GET /static/raphael-min.js HTTP / 1.1304  -  
 127.0.0.1  -   -  [17 / Aug / 2011 17:27： 29]GET /static/ivtl.css HTTP / 1.1304  -  
 127.0.0.1  -   -  [17 / Aug / 2011 17:27:29]GET /favicon.ico HTTP / 1.1404  -  $ 
 127.0.0.1  -   -  [17 / Aug / 2011 17:27:31]GET / viewgroup / DeviceInformation HTTP / 1.1200  -  
  

我需要所有57个小组留下来。任何提示？

解决方案

数据太大而无法序列化到会话中。现在我生成一个全局字典的密钥，并将该密钥存储在会话中。

  gXmlData [path] = groups 
  

问题在于，全球字典将会随着越来越多的密钥而永远停留，但是这个过程并不意味着长寿。

I'm writing a quick app to view a giant XML file with some AJAX style calls to viewgroup. My problem is session['groups'] not persisting. I have some old array with only 4 members that is stuck somewhere (cookie?..). That value is present when view is called. I then overwrite that session member with info from the recently opened xml file that contains 20+ members.

However, when viewgroup is called the session variable has reverted to the old value with only 4 members in the array!

Code followed by output. Note the 3 sessionStatus() calls

def sessionStatus():
    print "# of groups in session = " + str(len(session['groups']))

@app.route('/')
def index():
    cams = [file for file in os.listdir('xml/') if file.lower().endswith('xml')]
    return render_template('index.html', cam_files=cams)

@app.route('/view/<xmlfile>')
def view(xmlfile):
    path = 'xml/' + secure_filename(xmlfile)
    print 'opening ' + path
    xmlf = open(path, 'r')
    tree = etree.parse(xmlf)
    root = tree.getroot()
    p = re.compile(r'Group')
    groups = []
    for g in root:
        if (p.search(g.tag) is not None) and (g.attrib['Comment'] != 'Root'):
            groups.append(Group(g.attrib['Comment']))
    sessionStatus()
    session['groups'] = groups
    sessionStatus()
    return render_template('view.html', xml=xmlfile, groups=groups)

@app.route('/viewgroup/<name>')
def viewGroup(name):
    groups = session['groups']
    sessionStatus()        
    if groups is None or len(groups) == 0:
        raise Exception('invalid group name')
    groups_filtered = [g for g in groups if g.name == name]
    if len(groups_filtered) != 1:
        raise Exception('invalid group name', groups_filtered)
    group = groups_filtered[0]
    prop_names = [p.name for p in group.properties]
    return prop_names

Output

opening xml/d.xml
# of groups in session = 5
# of groups in session = 57
127.0.0.1 - - [17/Aug/2011 17:27:29] "GET /view/d.xml HTTP/1.1" 200 -
127.0.0.1 - - [17/Aug/2011 17:27:29] "GET /static/ivtl.css HTTP/1.1" 304 -
127.0.0.1 - - [17/Aug/2011 17:27:29] "GET /static/jquery.js HTTP/1.1" 304 -
127.0.0.1 - - [17/Aug/2011 17:27:29] "GET /static/raphael-min.js HTTP/1.1" 304 -
127.0.0.1 - - [17/Aug/2011 17:27:29] "GET /static/ivtl.css HTTP/1.1" 304 -
127.0.0.1 - - [17/Aug/2011 17:27:29] "GET /favicon.ico HTTP/1.1" 404 -
# of groups in session = 5
127.0.0.1 - - [17/Aug/2011 17:27:31] "GET /viewgroup/DeviceInformation HTTP/1.1" 200 -

I need all 57 groups to stay around. Any hints?

解决方案

The data was simply too big to serialize into the session. Now I generate a key into a global dict and store that key in the session.

gXmlData[path] = groups    

There's the problem that the global dict will stay around forever with more and more keys but the process isn't meant to live long.

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