From 537b1614c475ac1a9ff7455eae7e447c7d4a709f Mon Sep 17 00:00:00 2001
From: MatthieuParis <19178125+MatthieuParis@users.noreply.github.com>
Date: Sun, 8 Aug 2021 19:20:15 +0200
Subject: [PATCH 1/3] Display warnings when saving draft if another user is
 editing the page or if the page was updated since the current user has
 started editing the page.

---
 app/Entities/Tools/PageEditActivity.php | 11 +++++++++++
 app/Http/Controllers/PageController.php | 18 ++++++++++++++++++
 resources/js/components/page-editor.js  |  3 +++
 3 files changed, 32 insertions(+)

diff --git a/app/Entities/Tools/PageEditActivity.php b/app/Entities/Tools/PageEditActivity.php
index a88dea830..052427f6c 100644
--- a/app/Entities/Tools/PageEditActivity.php
+++ b/app/Entities/Tools/PageEditActivity.php
@@ -26,6 +26,7 @@ class PageEditActivity
      */
     public function hasActiveEditing(): bool
     {
+        $value = $this->activePageEditingQuery(60)->count();
         return $this->activePageEditingQuery(60)->count() > 0;
     }
 
@@ -43,6 +44,16 @@ class PageEditActivity
         return trans('entities.pages_draft_edit_active.message', ['start' => $userMessage, 'time' => $timeMessage]);
     }
 
+    /**
+     * Check if the page has been updated since the draft has been saved.
+     *
+     * @return bool
+     */
+    public function hasPageBeenUpdatedSinceDraftSaved(PageRevision $draft): bool
+    {
+        return $draft->page->updated_at->timestamp >= $draft->updated_at->timestamp;
+    }
+
     /**
      * Get the message to show when the user will be editing one of their drafts.
      *
diff --git a/app/Http/Controllers/PageController.php b/app/Http/Controllers/PageController.php
index 853ac28fc..4818b5211 100644
--- a/app/Http/Controllers/PageController.php
+++ b/app/Http/Controllers/PageController.php
@@ -258,6 +258,23 @@ class PageController extends Controller
             return $this->jsonError(trans('errors.guests_cannot_save_drafts'), 500);
         }
 
+        // Check for active editing or time conflict
+        $warnings = [];
+        $jsonResponseWarning = '';
+        $editActivity = new PageEditActivity($page);
+        if ($editActivity->hasActiveEditing()) {
+            $warnings[] = $editActivity->activeEditingMessage();
+        }
+        $userDraft = $this->pageRepo->getUserDraft($page);
+        if ($userDraft !== null) {
+            if ($editActivity->hasPageBeenUpdatedSinceDraftSaved($userDraft)) {
+                $warnings[] = $editActivity->getEditingActiveDraftMessage($userDraft);
+            }
+        }
+        if (count($warnings) > 0) {
+            $jsonResponseWarning = implode("\n", $warnings);
+        }
+
         $draft = $this->pageRepo->updatePageDraft($page, $request->only(['name', 'html', 'markdown']));
 
         $updateTime = $draft->updated_at->timestamp;
@@ -265,6 +282,7 @@ class PageController extends Controller
         return response()->json([
             'status'    => 'success',
             'message'   => trans('entities.pages_edit_draft_save_at'),
+            'warning'   => $jsonResponseWarning,
             'timestamp' => $updateTime,
         ]);
     }
diff --git a/resources/js/components/page-editor.js b/resources/js/components/page-editor.js
index f66e23b19..e753b58e1 100644
--- a/resources/js/components/page-editor.js
+++ b/resources/js/components/page-editor.js
@@ -119,6 +119,9 @@ class PageEditor {
             }
             this.draftNotifyChange(`${resp.data.message} ${Dates.utcTimeStampToLocalTime(resp.data.timestamp)}`);
             this.autoSave.last = Date.now();
+            if (resp.data.warning.length > 0) {
+                window.$events.emit('warning', resp.data.warning);
+            }
         } catch (err) {
             // Save the editor content in LocalStorage as a last resort, just in case.
             try {

From c2e031ae3e012b82978424c5ea89eb416e283b82 Mon Sep 17 00:00:00 2001
From: MatthieuParis <19178125+MatthieuParis@users.noreply.github.com>
Date: Sun, 8 Aug 2021 20:35:12 +0200
Subject: [PATCH 2/3] Testing command suppressed.

---
 app/Entities/Tools/PageEditActivity.php | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/app/Entities/Tools/PageEditActivity.php b/app/Entities/Tools/PageEditActivity.php
index 052427f6c..991882bef 100644
--- a/app/Entities/Tools/PageEditActivity.php
+++ b/app/Entities/Tools/PageEditActivity.php
@@ -1,4 +1,4 @@
-<?php
+a<?php
 
 namespace BookStack\Entities\Tools;
 
@@ -26,7 +26,6 @@ class PageEditActivity
      */
     public function hasActiveEditing(): bool
     {
-        $value = $this->activePageEditingQuery(60)->count();
         return $this->activePageEditingQuery(60)->count() > 0;
     }
 

From 3c4415f3ff460ed7463ca7e674767dc570269b2f Mon Sep 17 00:00:00 2001
From: MatthieuParis <19178125+MatthieuParis@users.noreply.github.com>
Date: Sun, 8 Aug 2021 21:59:04 +0200
Subject: [PATCH 3/3] Typo.

---
 app/Entities/Tools/PageEditActivity.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/Entities/Tools/PageEditActivity.php b/app/Entities/Tools/PageEditActivity.php
index 991882bef..2e620aa2c 100644
--- a/app/Entities/Tools/PageEditActivity.php
+++ b/app/Entities/Tools/PageEditActivity.php
@@ -1,4 +1,4 @@
-a<?php
+<?php
 
 namespace BookStack\Entities\Tools;