File size: 3,339 Bytes
bee9bbb | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 | """Bounded browser settling for lazy-loaded offline clone pages."""
from __future__ import annotations
import time
from typing import Any
_OBSERVE_SCRIPT = """
() => {
const root = document.documentElement;
const images = [...document.images];
const failedImages = images
.filter((image) => image.complete && image.naturalWidth === 0)
.map((image) => image.currentSrc || image.src || image.alt || "unknown");
const scrollHeight = root.scrollHeight;
const atBottom = window.scrollY + window.innerHeight >= scrollHeight - 2;
if (!atBottom) window.scrollBy(0, Math.max(1, window.innerHeight - 24));
return {
scroll_height: scrollHeight,
section_count: document.querySelectorAll("main section, main article, main h2").length,
image_count: images.length,
loaded_image_count: images.filter((image) => image.complete && image.naturalWidth > 0).length,
failed_images: failedImages,
at_bottom: atBottom,
};
}
"""
def _signature(observation: dict[str, Any]) -> tuple[Any, ...]:
return (
observation.get("scroll_height"),
observation.get("section_count"),
observation.get("image_count"),
observation.get("loaded_image_count"),
tuple(observation.get("failed_images") or ()),
)
def settle_page(
page: Any,
*,
max_rounds: int = 24,
timeout_ms: int = 20_000,
pause_ms: int = 100,
) -> dict[str, Any]:
"""Scroll and wait for a bounded, fully loaded page state.
Completion requires two consecutive bottom observations with identical
geometry/counts and every image loaded successfully. The return value is
deliberately serializable so scenarios can retain incomplete diagnostics.
"""
deadline = time.monotonic() + timeout_ms / 1000
previous_signature: tuple[Any, ...] | None = None
stable_bottom_observations = 0
latest: dict[str, Any] = {
"scroll_height": 0,
"section_count": 0,
"image_count": 0,
"loaded_image_count": 0,
"failed_images": [],
"at_bottom": False,
}
for _round in range(max_rounds):
if time.monotonic() >= deadline:
break
latest = dict(page.evaluate(_OBSERVE_SCRIPT))
signature = _signature(latest)
if latest.get("at_bottom") and signature == previous_signature:
stable_bottom_observations += 1
elif latest.get("at_bottom"):
stable_bottom_observations = 1
else:
stable_bottom_observations = 0
previous_signature = signature
images_healthy = (
latest.get("image_count", 0) == latest.get("loaded_image_count", 0)
and not latest.get("failed_images")
)
if stable_bottom_observations >= 2 and images_healthy:
return {**latest, "complete": True, "incomplete_reason": None}
if pause_ms:
page.wait_for_timeout(pause_ms)
if latest.get("failed_images"):
reason = "image load failures remain"
elif latest.get("image_count") != latest.get("loaded_image_count"):
reason = "image health did not settle"
elif not latest.get("at_bottom"):
reason = "document did not reach the bottom"
else:
reason = "page geometry did not stabilize"
return {**latest, "complete": False, "incomplete_reason": reason}
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