Automatically expand child nodes as well as the selected node on the treeview if there is only one. Fixes #3559

This also ensure the browser state is cleared if the save interval is set to -1.

web/pgadmin/browser/register_browser_preferences.py

@@ -48,6 +48,16 @@ def register_browser_preferences(self):
         )
     )
 
+    self.preference.register(
+        'display', 'auto_expand_sole_children',
+        gettext("Auto-expand sole children"), 'boolean', True,
+        category_label=gettext('Display'),
+        help_str=gettext(
+            'If a treeview node is expanded and has only a single '
+            'child, automatically expand the child node as well.'
+        )
+    )
+
     self.table_row_count_threshold = self.preference.register(
         'properties', 'table_row_count_threshold',
         gettext("Count rows if estimated less than"), 'integer', 2000,

web/pgadmin/browser/static/js/node.js

@@ -999,8 +999,17 @@ define('pgadmin.browser.node', [
           });
       },
       opened: function(item) {
+        let tree = pgBrowser.tree,
+          auto_expand = pgBrowser.get_preference('browser', 'auto_expand_sole_children');
+
         pgBrowser.Events.trigger('pgadmin:browser:tree:update-tree-state',
          item);
+
+        if (auto_expand && auto_expand.value == true && tree.children(item).length == 1) {
+          // Automatically expand the child node, if a treeview node has only a single child.
+          tree.open(tree.first(item));
+        }
+
       },
       closed: function(item) {
         pgBrowser.Events.trigger('pgadmin:browser:tree:remove-from-tree-state',

web/pgadmin/settings/__init__.py

@@ -55,7 +55,8 @@ class SettingsModule(PgAdminModule):
         """
         return [
             'settings.store', 'settings.store_bulk', 'settings.reset_layout',
-            'settings.save_tree_state', 'settings.get_tree_state'
+            'settings.save_tree_state', 'settings.get_tree_state',
+            'settings.reset_tree_state'
         ]
 
 
@@ -150,6 +151,24 @@ def reset_layout():
     return make_json_response(result=request.form)
 
 
+@blueprint.route("/reset_tree_state", methods=['DELETE'], endpoint='reset_tree_state')
+@login_required
+def reset_tree_state():
+    """Reset the saved tree state."""
+
+    data = Setting.query.filter_by(user_id=current_user.id, setting='browser_tree_state').first()
+    try:
+        if data is not None:
+            db.session.delete(data)
+            db.session.commit()
+    except Exception as e:
+        return make_json_response(
+            status=410, success=0, errormsg=str(e)
+        )
+
+    return success_return()
+
+
 @blueprint.route("/save_tree_state/", endpoint="save_tree_state",
                  methods=['POST'])
 @login_required

web/pgadmin/static/js/tree/pgadmin_tree_save_state.js

@@ -69,7 +69,27 @@ _.extend(pgBrowser.browserTreeState, {
         this.remove_from_cache, this);
       pgBrowser.Events.on('pgadmin:browser:tree:update-tree-state',
         this.update_cache, this);
+    } else {
+      $.ajax({
+        url: url_for('settings.reset_tree_state'),
+        type: 'DELETE',
+      })
+      .fail(function(jqx) {
+        var msg = jqx.responseText;
+        /* Error from the server */
+        if (jqx.status == 417 || jqx.status == 410 || jqx.status == 500) {
+          try {
+            var data = JSON.parse(jqx.responseText);
+            msg = data.errormsg;
+          } catch (e) {
+            console.warn(e.stack || e);
+          }
+        }
+        console.warn(
+          gettext('Error resetting the tree saved state."'), msg);
+      });
     }
+
   },
   save_state: function() {