From 1764b55dbdfd922755d6204b042e367cb9221737 Mon Sep 17 00:00:00 2001
From: Jonas Tranberg <jonastranberg93@gmail.com>
Date: Sun, 5 Jul 2020 03:10:08 +0200
Subject: [PATCH] Added failed load detection

---
 README.md                   |  1 +
 internal/browser/browser.go | 17 +++++++++++++++++
 internal/browser/tab.go     | 18 +++++++++++++++++-
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 0c3481c..82d15df 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ YAML configurable web dashboard viewer written in Go
 - Cron jobs
   - System commands
   - Message flashing
+- Detect failed page loads and retry
 
 ## About
 
diff --git a/internal/browser/browser.go b/internal/browser/browser.go
index b2abb46..4c972ab 100644
--- a/internal/browser/browser.go
+++ b/internal/browser/browser.go
@@ -4,7 +4,10 @@ import (
 	"context"
 	"log"
 
+	"github.com/chromedp/cdproto/network"
+	"github.com/chromedp/cdproto/target"
 	"github.com/chromedp/chromedp"
+	"github.com/sirupsen/logrus"
 )
 
 type Browser struct {
@@ -39,6 +42,20 @@ func (b *Browser) NewTab() Tab {
 		Context: ctx,
 	}
 
+	chromedp.ListenTarget(ctx, func(ev interface{}) {
+		if e, ok := ev.(*network.EventLoadingFailed); ok {
+			if e.Type == network.ResourceTypeDocument {
+				logrus.Infof("Tab failed to load, reloading in %v seconds\n", FailedLoadReloadDelay.Seconds())
+
+				go t.delayedReload()
+			}
+		}
+
+		if _, ok := ev.(*target.EventTargetDestroyed); ok {
+			b.removeTab(t)
+		}
+	})
+
 	t.Close = func() {
 		b.removeTab(t)
 		close()
diff --git a/internal/browser/tab.go b/internal/browser/tab.go
index b1831a3..5945d50 100644
--- a/internal/browser/tab.go
+++ b/internal/browser/tab.go
@@ -3,6 +3,7 @@ package browser
 import (
 	"context"
 	"encoding/base64"
+	"time"
 
 	"github.com/chromedp/cdproto/network"
 	"github.com/chromedp/cdproto/page"
@@ -10,11 +11,17 @@ import (
 	"github.com/chromedp/chromedp"
 )
 
+var (
+	FailedLoadReloadDelay = time.Second * 10
+)
+
 type Tab struct {
 	Browser Browser
 	Context context.Context
 
 	Close func()
+
+	isReloading bool
 }
 
 type BasicAuthCredentials struct {
@@ -31,7 +38,7 @@ func (t *Tab) Reload() {
 }
 
 func (t *Tab) Navigate(url string) {
-	chromedp.Run(t.Context, chromedp.Navigate(url))
+	chromedp.Run(t.Context, network.Enable(), chromedp.Navigate(url))
 }
 
 func (t *Tab) NavigateWithBasicAuth(url string, creds BasicAuthCredentials) {
@@ -69,3 +76,12 @@ func (t *Tab) AddJS(script string) {
 		chromedp.EvaluateAsDevTools(script, &executed),
 	)
 }
+
+func (t *Tab) delayedReload() {
+	if !t.isReloading {
+		t.isReloading = true
+		time.Sleep(FailedLoadReloadDelay)
+		t.isReloading = false
+		t.Reload()
+	}
+}