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import urllib.parse
from wptserve.utils import isomorphic_encode
def main(request, response):
"""Handler that causes multiple redirections. Redirect chain is as follows:
1. Initial URL containing
2. Redirect to cross-origin URL
3. Redirect to same-origin URL
4. Final URL containing the final same-origin resource.
Mandatory parameters:
page_origin - The page origin, used for redirection and to set TAO. This is a mandatory parameter.
cross_origin - The cross origin used to make this a cross-origin redirect. This is a mandatory parameter.
final_resource - Path of the final resource, without origin. This is a mandatory parameter.
Optional parameters:
tao_steps - Number of redirects for which the TAO header will be present (a number 0 - 3 makes the most sense). Default value is 0.
tao_value - The value of the TAO header, when present. Default value is "*".
Note that |step| is a parameter used internally for the multi-redirect. It's the step we're at in the redirect chain.
step = 1
if b"step" in request.GET:
step = int(request.GET.first(b"step"))
except ValueError:
page_origin = request.GET.first(b"page_origin")
cross_origin = request.GET.first(b"cross_origin")
final_resource = request.GET.first(b"final_resource")
tao_value = b"*"
if b"tao_value" in request.GET:
tao_value = request.GET.first(b"tao_value")
tao_steps = 0
if b"tao_steps" in request.GET:
tao_steps = int(request.GET.first(b"tao_steps"))
next_tao_steps = tao_steps - 1
redirect_url_path = b"/resource-timing/resources/"
redirect_url_path += b"page_origin=" + page_origin
redirect_url_path += b"&cross_origin=" + cross_origin
redirect_url_path += b"&final_resource=" + urllib.parse.quote(final_resource).encode('ascii')
redirect_url_path += b"&tao_value=" + tao_value
redirect_url_path += b"&tao_steps=" + isomorphic_encode(str(next_tao_steps))
redirect_url_path += b"&step="
if tao_steps > 0:
response.headers.set(b"timing-allow-origin", tao_value)
if step == 1:
# On the first request, redirect to a cross origin URL
redirect_url = cross_origin + redirect_url_path + b"2"
elif step == 2:
# On the second request, redirect to a same origin URL
redirect_url = page_origin + redirect_url_path + b"3"
# On the third request, redirect to a static response
redirect_url = page_origin + final_resource
response.status = 302
response.headers.set(b"Location", redirect_url)