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htmlcherrypy

Update field with CherryPy

I'm pretty new to web development so please bear with me. I have a control webpage (run by cherrypy) with status values representing a python process running serverside. How can I update or push the new values?

The only way I would now how would be with something like:

<meta http-equiv="refresh" content="1">

which updates the entire page. I would however prefer with only needed fields gets updated. Is this easily possible with pure html respectively directly by cherrypy?

Solution

  • The optimal way is using javascript/websockets/ajax.

    But given the constraints of "server side only". I believe you can accomplish that with iframes.

    import  cherrypy as cp

MAIN_PAGE = """
<html>
  <body>
    <h1> Im the main page! </h1>
    <iframe frameBorder="0"  src="/frame"></iframe>
  </body>
</html>
"""

FRAME_PAGE = """
<html>
  <head>
   <meta http-equiv="refresh" content="1">
  </head>
  <body>
     Counter: <strong>{}</strong>
  </body>
</html>
"""

class Root:

    def __init__(self):
        self.counter = 0

    @cp.expose
    def default(self):
        return MAIN_PAGE

    @cp.expose
    def frame(self):
        self.counter += 1
        return FRAME_PAGE.format(self.counter)

cp.quickstart(Root())

    Which is indeed reloading a full page, but just within the frame. To avoid the blinking on the iframe, you will need some javascript/css.