Python POST data using mod_wsgi

Question

This must be a very simple question, but I don't seem to be able to figure out.

I'm using apache + mod_wsgi to host my python application, and I'd like to get the post content submitted in one of the forms -however, neither the environment values, nor sys.stdin contains any of this data. Mind giving me a quick hand?

Edit: Tried already:

• environ["CONTENT_TYPE"] = 'application/x-www-form-urlencoded' (no data)
• environ["wsgi.input"] seems a plausible way, however, both environ["wsgi.input"].read(), and environ["wsgi.input"].read(-1) returns an empty string (yes, content has been posted, and environ["request_method"] = "post"

Answer 1

PEP 333 says you must read environ['wsgi.input'].

I just saved the following code and made apache's mod_wsgi run it. It works.

You must be doing something wrong.

from pprint import pformat

def application(environ, start_response):
    # show the environment:
    output = ['<pre>']
    output.append(pformat(environ))
    output.append('</pre>')

    #create a simple form:
    output.append('<form method="post">')
    output.append('<input type="text" name="test">')
    output.append('<input type="submit">')
    output.append('</form>')

    if environ['REQUEST_METHOD'] == 'POST':
        # show form data as received by POST:
        output.append('<h1>FORM DATA</h1>')
        output.append(pformat(environ['wsgi.input'].read()))

    # send results
    output_len = sum(len(line) for line in output)
    start_response('200 OK', [('Content-type', 'text/html'),
                              ('Content-Length', str(output_len))])
    return output

Answer 2

Be aware that technically speaking calling read() or read(-1) on wsgi.input is a violation of the WSGI specification even though Apache/mod_wsgi allows it. This is because the WSGI specification requires that a valid length argument be supplied. The WSGI specification also says you shouldn't read more data than is specified by the CONTENT_LENGTH.

So, the code above may work in Apache/mod_wsgi but it isn't portable WSGI code and will fail on some other WSGI implementations. To be correct, determine request content length and supply that value to read().