Восстанавливать загрузку30мин после Reload и удерживать Back (#9)

components/navigation-guard.php

@@ -0,0 +1,70 @@
+<?php
+// Общий inline-контракт Back для незавершённой публичной операции (api#299/preland#9).
+return <<<'JS'
+(() => {
+	let active = false;
+	let hasHistoryEntry = false;
+	let releasingHistoryEntry = false;
+	let returningToSentinel = false;
+
+	function pushGuardEntries() {
+		// Помечаем и текущую запись Tour, и sentinel сверху. Иначе первый Back
+		// останавливался на немаркированной записи, а второй мог уйти в about:blank.
+		window.history.replaceState({ publicOperationGuard: true }, '', window.location.href);
+		window.history.pushState({ publicOperationGuard: true }, '', window.location.href);
+		hasHistoryEntry = true;
+	}
+
+	function onPopState(event) {
+		if (releasingHistoryEntry) {
+			releasingHistoryEntry = false;
+			return;
+		}
+
+		if (active) {
+			if (returningToSentinel) {
+				returningToSentinel = false;
+				return;
+			}
+			returningToSentinel = true;
+			window.history.go(1);
+		}
+	}
+
+	function deactivate(onReleased) {
+		if (!active) {
+			if (onReleased) {
+				if (releasingHistoryEntry) {
+					window.addEventListener('popstate', onReleased, { once: true });
+				} else {
+					onReleased();
+				}
+			}
+			return;
+		}
+		active = false;
+
+		if (hasHistoryEntry) {
+			hasHistoryEntry = false;
+			releasingHistoryEntry = true;
+			if (onReleased) window.addEventListener('popstate', onReleased, { once: true });
+			window.history.back();
+			return;
+		}
+		if (onReleased) onReleased();
+	}
+
+	window.addEventListener('popstate', onPopState);
+	window.PublicNavigationGuard = {
+		activate() {
+			if (active) return;
+			releasingHistoryEntry = false;
+			returningToSentinel = false;
+			active = true;
+			pushGuardEntries();
+		},
+		deactivate,
+		allowNavigation: deactivate,
+	};
+})();
+JS;