Handle transient network suspension in frontend polling and SSE

static/js/core/alerts.js

@@ -7,6 +7,7 @@ const AlertCenter = (function() {
     let rules = [];
     let eventSource = null;
     let reconnectTimer = null;
+    let lastConnectionWarningAt = 0;
 
     function init() {
         loadRules();
@@ -31,7 +32,14 @@ const AlertCenter = (function() {
         };
 
         eventSource.onerror = function() {
-            console.warn('[Alerts] SSE connection error');
+            const now = Date.now();
+            const offline = (typeof window.isOffline === 'function' && window.isOffline()) ||
+                (typeof navigator !== 'undefined' && navigator.onLine === false);
+            const shouldLog = !offline && !document.hidden && (now - lastConnectionWarningAt) > 15000;
+            if (shouldLog) {
+                lastConnectionWarningAt = now;
+                console.warn('[Alerts] SSE connection error; retrying');
+            }
             if (reconnectTimer) clearTimeout(reconnectTimer);
             reconnectTimer = setTimeout(connect, 2500);
         };

static/js/core/run-state.js

@@ -92,8 +92,9 @@ const RunState = (function() {
             renderHealth(data);
         } catch (err) {
             renderHealth(null, err);
+            const transient = isTransientFailure(err);
             const now = Date.now();
-            if (typeof reportActionableError === 'function' && (now - lastErrorToastAt) > 30000) {
+            if (!transient && typeof reportActionableError === 'function' && (now - lastErrorToastAt) > 30000) {
                 lastErrorToastAt = now;
                 reportActionableError('Run State', err, { persistent: false });
             }
@@ -214,6 +215,17 @@ const RunState = (function() {
         return String(err);
     }
 
+    function isTransientFailure(err) {
+        if (typeof window.isTransientOrOffline === 'function' && window.isTransientOrOffline(err)) {
+            return true;
+        }
+        if (typeof navigator !== 'undefined' && navigator.onLine === false) {
+            return true;
+        }
+        const text = extractMessage(err).toLowerCase();
+        return text.includes('failed to fetch') || text.includes('network') || text.includes('timeout');
+    }
+
     function getLastHealth() {
         return lastHealth;
     }

static/js/core/ui-feedback.js

@@ -208,9 +208,31 @@ const AppFeedback = (function() {
         return state;
     }
 
+    function isOffline() {
+        return typeof navigator !== 'undefined' && navigator.onLine === false;
+    }
+
+    function isTransientNetworkError(error) {
+        const text = String(extractMessage(error) || '').toLowerCase();
+        if (!text) return false;
+
+        return text.includes('networkerror') ||
+            text.includes('failed to fetch') ||
+            text.includes('network request failed') ||
+            text.includes('load failed') ||
+            text.includes('err_network_io_suspended') ||
+            text.includes('network io suspended') ||
+            text.includes('the network connection was lost') ||
+            text.includes('connection reset') ||
+            text.includes('timeout');
+    }
+
+    function isTransientOrOffline(error) {
+        return isOffline() || isTransientNetworkError(error);
+    }
+
     function isNetworkError(message) {
-        const text = String(message || '').toLowerCase();
+        return isTransientNetworkError(message);
-        return text.includes('networkerror') || text.includes('failed to fetch') || text.includes('timeout');
     }
 
     function isSettingsError(message) {
@@ -224,6 +246,9 @@ const AppFeedback = (function() {
         reportError,
         removeToast,
         renderCollectionState,
+        isOffline,
+        isTransientNetworkError,
+        isTransientOrOffline,
     };
 })();
 
@@ -243,6 +268,18 @@ window.renderCollectionState = function(container, options) {
     return AppFeedback.renderCollectionState(container, options);
 };
 
+window.isOffline = function() {
+    return AppFeedback.isOffline();
+};
+
+window.isTransientNetworkError = function(error) {
+    return AppFeedback.isTransientNetworkError(error);
+};
+
+window.isTransientOrOffline = function(error) {
+    return AppFeedback.isTransientOrOffline(error);
+};
+
 document.addEventListener('DOMContentLoaded', () => {
     AppFeedback.init();
 });

templates/index.html

@@ -5655,10 +5655,19 @@
                     renderSdrStatus(devices);
                 })
                 .catch(err => {
-                    console.error('Failed to fetch SDR status:', err);
+                    const transient = (typeof window.isTransientOrOffline === 'function' && window.isTransientOrOffline(err)) ||
+                        (typeof navigator !== 'undefined' && navigator.onLine === false) ||
+                        /failed to fetch|network io suspended|networkerror|timeout/i.test(String((err && err.message) || err || ''));
+                    if (!transient) {
+                        console.error('Failed to fetch SDR status:', err);
+                    }
                     const container = document.getElementById('sdrStatusList');
                     if (container) {
-                        container.innerHTML = '<div style="padding: 8px; color: #ff6666; font-size: 11px; text-align: center;">Error loading status</div>';
+                        if (transient) {
+                            container.innerHTML = '<div style="padding: 8px; color: #888; font-size: 11px; text-align: center;">Status temporarily unavailable</div>';
+                        } else {
+                            container.innerHTML = '<div style="padding: 8px; color: #ff6666; font-size: 11px; text-align: center;">Error loading status</div>';
+                        }
                     }
                 });
         }

templates/satellite_dashboard.html

@@ -971,7 +971,12 @@
                     }
                 }
             } catch (err) {
-                console.error('Position update error:', err);
+                const transient = (typeof window.isTransientOrOffline === 'function' && window.isTransientOrOffline(err)) ||
+                    (typeof navigator !== 'undefined' && navigator.onLine === false) ||
+                    /failed to fetch|network io suspended|networkerror|timeout/i.test(String((err && err.message) || err || ''));
+                if (!transient) {
+                    console.error('Position update error:', err);
+                }
             }
         }