[Twisted-Python] Page.renderString returns Deferred at <addr> current result: 'blah'

Fri Dec 24 16:05:07 EST 2004

On Fri, Dec 24, 2004 at 12:10:16PM -0800, Alan Ezust wrote:
> I'm playing around with Twisted for my first time, and I noticed that 
> page.renderString() returns a string like this:
> 
> <Deferred at 0x4054616c  current result: '<html>\n  <head>\n   
> <title>Greetings!</title>\n  </head>\n  <body>\n    <h1
> style="font-size: large">Now I will greet you:</h1>\n    Hi My name
> is\n  </body>\n</html>'>
> 
> First, why the Deferred result?

I suspect it is because renderString might well want to do other
operations in order to construct the string, and the result may
not be immediately available.

> Second, what if I just want the actual string? What method should I
> call? Or am I supposed to do something else to this before getting the
> renderString?

You could do somethign like:

def _cbDoSomethingWithString(str):
    print str

page.renderString().addCallback(_cbDoSomethingWithString)

There is also a helper function that you can use:

    s = page.renderString()
    from twisted.trial.util import wait
    s = wait(s)

though I am not sure how advisable it is to use that, depending on
what exactly it is you are trying to do...

Cheers,
-w