passing Python data to a javascript function

Wed Oct 26 22:25:16 EDT 2011

Benjamin,

I was afraid I was doing that.   I have simplified it quite a bit, still not
getting the output I am looking for.   I am down to that I am not passing
the value in the onload=showPID() call correctly.  I know this is getting a
bit far from a Python issue now, but if you have more insight on this, I
would appreciate it.  Is there another way of passing the data from the
Python script to the javascript than what I am doing in this CGI?

Thanks,
Bill

code now is:

import os, cgi, cgitb
cgitb.enable()

pid_data = str(os.getpid())
print "Content-type: text/html"
print

print """
<html>
<head><title>Test Page</title>
<script type="text/javascript">
function showPID(pid){
document.getElementById('txt').innerHTML="js: "+pid;
}
</script>
</head>
<body onload="showPID(pid_data)">

Hello World!<br><br>
<div id="txt"></div><br>
"""
print "html: "+pid_data+"<br>"
print """
</body>
</html>"""

If I use <body onload="showPID(pid_data)"> I get this for output:
Hello World!

html: 4900

If I use <body onload="showPID('pid_data')"> I get this for output:
Hello World!

js: pid_data

html: 4708

On Wed, Oct 26, 2011 at 17:58, Benjamin Kaplan <benjamin.kaplan at case.edu>wrote:

> On Wed, Oct 26, 2011 at 6:18 PM, Bill Allen <wallenpb at gmail.com> wrote:
> >
> > I am writing a Python CGI and am needing to pass a data value from Python
> to a javascript function.   My understanding is that I should use JSON as
> the middleman.  However, I have not found a good example of doing this.
> The piece of data is a simple integer, but I could easily covert that to a
> string first if necessary.   Here is what I am trying, but unsuccessfully.
> I am sure that I have more than one issue in this code.
> >
> >
> >
> > #!/usr/bin/python
> >
> > import json, os, cgi, cgitb
> > cgitb.enable()
> >
> > pid = [{'p':str(os.getpid())}]
> > pid_data = json.dumps(pid)
> >
> > print "Content-type: text/html"
> > print
> >
> > print """
> > <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
> > "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
> > <html xmlns="http://www.w3.org/1999/xhtml">
> > <head><title>Test Page</title>
> > <script type="text/javascript">
> > function showPId(pid_data)
> > {
> > var a_pid=eval("(" + pid_data + ")");
> > document.getElementById('txt').innerHTML=a_pid;
> > }
> > </script>
> > </head>
> > <body onload="startTime({0})">
> >
> > <center><div id="txt"></div></center><br>
> >
> > </body>
> > </html>""".format(pid_data)
> >
>
> You're making this much more difficult than it needs to be. JSON is
> used for sending data to JavaScript, meaning the JavaScript asks the
> server for a bunch of data, the server sends the client JSON, and
> everyone is happy. In your case, the information is available when the
> javascript is being generated so you can just pass in the number, no
> JSON needed.
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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