Source code
Revision control
Copy as Markdown
Other Tools
""" Handle the initiator navigation request and attach the received client info
to the returned page.
"""
import textwrap
html_template = """
<!DOCTYPE html>
<html>
<head>
<title>echo client hints on prerendering page</title>
</head>
<script src="/speculation-rules/prerender/resources/utils.js"></script>
<body>
<script>
// Allow generator to add the received CH information into this script.
%s
const params = new URLSearchParams(location.search);
const uid = params.get('uid');
// Performs the check below on initiator pages:
// 1. The client did not send server_received_full_version_list when fetching
// the initiator page.
// If the check fails, it will ask the main test page to terminate the test.
// Otherwise, it will:
// 1. Initiate a prerendering action. And the prerendering page will perform
// some checks.
// 2. Wait for the prerendering page to pass all checks and send a signal back.
// 3. Activate the prerendered page.
async function load_as_initiator_page() {
if (!server_received_bitness || server_received_full_version_list) {
// The initial headers are not as expected. Terminate the test.
failTest(
`unexpected initial headers.
bitness: ${server_received_bitness},
full_version: ${server_received_full_version_list}`,
uid);
return;
}
const prerendering_url =
`./echo-prerender-page-client-hints-received.py?uid=${uid}`;
// Wait for the prerendered page to be ready for activation.
const bc = new PrerenderChannel('prerender-channel', uid);
const gotMessage = new Promise(resolve => {
bc.addEventListener('message', e => {
resolve(e.data);
}, {once: true});
});
startPrerendering(prerendering_url);
data = await gotMessage;
if (data == 'ready for activation') {
window.location = prerendering_url;
} else {
failTest(`Initial page received unexpected result: ${data}`, uid);
}
}
load_as_initiator_page();
</script>
</body>
</html>
"""
def translate_to_js(val: bool) -> str:
if isinstance(val, bool):
return "true" if val else "false"
return ""
def main(request, response):
response.status = 200
# Insert the received hints into script.
content = html_template % (
textwrap.dedent(
f"""
const server_received_bitness =
{translate_to_js(b"sec-ch-ua-bitness" in request.headers)};
const server_received_full_version_list =
{translate_to_js(b"sec-ch-ua-full-version-list" in
request.headers)};
"""
)
)
response.content = content.encode("utf-8")