在Django模板的Javascript中使用从Django视图生成的变量？

Question

This variable below stores the processing in variable name proc :

proc = subprocess.Popen(['sshpass', '-p', password, 'rsync', '-avz', '--info=progress2', source12, destination], 
                                    stderr=subprocess.PIPE, stdout=subprocess.PIPE).communicate()[0]

I am a form in a Django template. Whenever the user presses the button Submit I want to use the variable proc and show the processing. I tried using the variable proc in Django template Javascript like this:

function popUp() {
    var a = "{{proc}}"
    document.write(a)
}
</script>

But it shows only the empty page. I have tested variable directly calling inside the html body tag it works fine but doesn't work with javascript. What I am doing wrong?

I am calling the popUp function like this in the Django template like this:

<form name="form1" action="/sync/" method="post" onsubmit="popUp()">

And, I am passing the variable proc in the Django template like this:

return render_to_response('synced.html', {'final_result':final_list}, context_instance=RequestContext(request))
return render_to_response('thanks.html', {'proc':proc}, context_instance=RequestContext(request))

Edit: For the checking, instead of passing the variable into thanks.html I passed the variable proc into synced.html and used in template like this:

<th>Files in the server:</th>
</tr>
<td>{{ proc }}</td>
<tr>

and my output is:

receiving incremental file list 0 0% 0.00kB/s 0:00:00 (xfr#0, to-chk=0/1) sent 20 bytes received 56 bytes 6.08 bytes/sec total size is 8,640 speedup is 113.68

Answer 1

I suggest what you are doing is not wrong but there are better ways & technologies have been engineered to solve this usecase of yours. Some of the things you can try -

1. AJAX Polling - Use a client-side timer, you constantly poll the server about it's status.
2. COMET - comet is a PUSH technology. As HTTP is a pull technology you can have a persistent connection between server & client and have server PUSH the progress to you.

Not the answer you were looking for but hopefully this helps...