Add changelog link to updates screen - Fixes #4101

modules/system/classes/UpdateManager.php

@@ -748,6 +748,39 @@ class UpdateManager
         $this->productCache[$type][$code] = $data;
     }
 
+    //
+    // Changelog
+    //
+
+    /**
+     * Returns the latest changelog information.
+     */
+    public function requestChangelog()
+    {
+        $result = Http::get('https://octobercms.com/changelog?json');
+
+        if ($result->code == 404) {
+            throw new ApplicationException(Lang::get('system::lang.server.response_empty'));
+        }
+
+        if ($result->code != 200) {
+            throw new ApplicationException(
+                strlen($result->body)
+                ? $result->body
+                : Lang::get('system::lang.server.response_empty')
+            );
+        }
+
+        try {
+            $resultData = json_decode($result->body, true);
+        }
+        catch (Exception $ex) {
+            throw new ApplicationException(Lang::get('system::lang.server.response_invalid'));
+        }
+
+        return $resultData;
+    }
+
     //
     // Notes
     //

modules/system/controllers/Updates.php

@@ -699,6 +699,33 @@ class Updates extends Controller
         return Backend::redirect('system/updates');
     }
 
+    //
+    // View Changelog
+    //
+
+    /**
+     * Displays changelog information
+     */
+    public function onLoadChangelog()
+    {
+        try {
+            $fetchedContent = UpdateManager::instance()->requestChangelog();
+
+            $changelog = array_get($fetchedContent, 'history');
+
+            if (!$changelog || !is_array($changelog)) {
+                throw new ApplicationException(Lang::get('system::lang.server.response_empty'));
+            }
+
+            $this->vars['changelog'] = $changelog;
+        }
+        catch (Exception $ex) {
+            $this->handleError($ex);
+        }
+
+        return $this->makePartial('changelog_list');
+    }
+
     //
     // Plugin management
     //

modules/system/controllers/updates/_changelog_list.htm

@@ -0,0 +1,47 @@
+<div class="modal-header">
+    <button type="button" class="close" data-dismiss="popup">&times;</button>
+    <h4 class="modal-title"><?= e(trans('system::lang.updates.changelog')) ?></h4>
+</div>
+<div class="modal-body">
+
+    <?php if ($this->fatalError): ?>
+        <p class="flash-message static error"><?= e($fatalError) ?></p>
+    <?php else: ?>
+        <div class="control-updatelist">
+            <div class="control-scrollbar" style="height:400px" data-control="scrollbar">
+                <div class="update-item">
+                    <dl>
+                        <?php foreach ($changelog as $item): ?>
+                            <?php
+                                $description = array_get($item, 'description');
+                                $build = array_get($item, 'build');
+                                $linkUrl = array_get($item, 'link_url');
+                            ?>
+                            <dt><?= e(trans('system::lang.updates.core_build', ['build'=>$build])) ?></dt>
+                            <?php if ($linkUrl): ?>
+                                <dd>
+                                    <?= e($description) ?>
+                                    <a href="<?= $linkUrl ?>" target="_blank">
+                                        <?= e(trans('system::lang.updates.changelog_view_details')) ?>
+                                        <i class="icon-external-link"></i>
+                                    </a>
+                                </dd>
+                            <?php else: ?>
+                                <dd><?= e($description) ?></dd>
+                            <?php endif ?>
+                        <?php endforeach ?>
+                    </dl>
+                </div>
+            </div>
+        </div>
+    <?php endif ?>
+</div>
+
+<div class="modal-footer">
+    <button
+        type="button"
+        class="btn btn-default"
+        data-dismiss="popup">
+        <?= e(trans('backend::lang.form.close')) ?>
+    </button>
+</div>

modules/system/controllers/updates/index.htm

@@ -35,6 +35,14 @@
             <div class="scoreboard-item title-value">
                 <h4><?= e(trans('system::lang.updates.core_current_build')) ?></h4>
                 <p><?= $coreBuild ?></p>
+                <p class="description">
+                    <a
+                        href="javascript:;"
+                        data-control="popup"
+                        data-handler="onLoadChangelog">
+                        <?= e(trans('system::lang.updates.core_view_changelog')) ?>
+                    </a>
+                </p>
             </div>
         <?php endif ?>
     </div>

modules/system/lang/en/lang.php

@@ -317,11 +317,14 @@ return [
         'plugin_author' => 'Author',
         'plugin_not_found' => 'Plugin not found',
         'core_current_build' => 'Current build',
+        'core_view_changelog' => 'View Changelog',
         'core_build' => 'Build :build',
         'core_build_help' => 'Latest build is available.',
         'core_downloading' => 'Downloading application files',
         'core_extracting' => 'Unpacking application files',
         'core_set_build' => 'Setting build number',
+        'changelog' => 'Changelog',
+        'changelog_view_details' => 'View details',
         'plugins' => 'Plugins',
         'themes' => 'Themes',
         'disabled' => 'Disabled',