From cf7a3153f98aff6988646336c4c06653e4cd2027 Mon Sep 17 00:00:00 2001
From: Dmitry S <dsagal+git@gmail.com>
Date: Mon, 4 Oct 2021 19:52:20 -0400
Subject: [PATCH] (core) When hidden pages are present in the page list, allow
 removing them

Summary:
After an incomplete import, any GristHidden_* tables will show up in the page
list, but may not be removable if there is only one non-hidden table remaining.
Such tables should still be removable in this case.

Test Plan: Added a test case

Reviewers: georgegevoian

Reviewed By: georgegevoian

Differential Revision: https://phab.getgrist.com/D3058
---
 app/client/models/DocModel.ts      | 11 +++--------
 app/client/models/isHiddenTable.ts | 12 ++++++++++++
 app/client/ui/Pages.ts             |  7 ++++++-
 3 files changed, 21 insertions(+), 9 deletions(-)
 create mode 100644 app/client/models/isHiddenTable.ts

diff --git a/app/client/models/DocModel.ts b/app/client/models/DocModel.ts
index 65876cff..686c5740 100644
--- a/app/client/models/DocModel.ts
+++ b/app/client/models/DocModel.ts
@@ -22,7 +22,7 @@ import {urlState} from 'app/client/models/gristUrlState';
 import * as MetaRowModel from 'app/client/models/MetaRowModel';
 import * as MetaTableModel from 'app/client/models/MetaTableModel';
 import * as rowset from 'app/client/models/rowset';
-import {RowId} from 'app/client/models/rowset';
+import {isHiddenTable} from 'app/client/models/isHiddenTable';
 import {schema, SchemaTypes} from 'app/common/schema';
 
 import {ACLRuleRec, createACLRuleRec} from 'app/client/models/entities/ACLRuleRec';
@@ -207,16 +207,11 @@ export class DocModel {
 
 
 /**
- * Helper to create an observable array of tables, sorted by tableId, and excluding summary
+ * Helper to create an observable array of tables, sorted by tableId, and excluding hidden
  * tables.
  */
 function createUserTablesArray(tablesModel: MetaTableModel<TableRec>): KoArray<TableRec> {
-  // Create a rowSource that filters out table records with non-zero summarySourceTable
-  // and GristHidden tables for import.
-  const tableIdGetter = tablesModel.tableData.getRowPropFunc('tableId') as (r: RowId) => string;
-  const sumTableGetter = tablesModel.tableData.getRowPropFunc('summarySourceTable') as (r: RowId) => number;
-  const rowSource = new rowset.FilteredRowSource(r => (sumTableGetter(r) === 0 &&
-                                                     !tableIdGetter(r).startsWith('GristHidden')));
+  const rowSource = new rowset.FilteredRowSource(r => !isHiddenTable(tablesModel.tableData, r));
   rowSource.subscribeTo(tablesModel);
   // Create an observable RowModel array based on this rowSource, sorted by tableId.
   return tablesModel._createRowSetModel(rowSource, 'tableId');
diff --git a/app/client/models/isHiddenTable.ts b/app/client/models/isHiddenTable.ts
new file mode 100644
index 00000000..20b285b2
--- /dev/null
+++ b/app/client/models/isHiddenTable.ts
@@ -0,0 +1,12 @@
+import {RowId} from 'app/client/models/rowset';
+import {TableData} from 'app/client/models/TableData';
+
+/**
+ * Return whether a table identified by the rowId of its metadata record, should normally be
+ * hidden from the user (e.g. as an option in the page-widget picker).
+ */
+export function isHiddenTable(tablesData: TableData, tableRef: RowId): boolean {
+  const tableId = tablesData.getValue(tableRef, 'tableId') as string|undefined;
+  return tablesData.getValue(tableRef, 'summarySourceTable') !== 0 ||
+    Boolean(tableId?.startsWith('GristHidden'));
+}
diff --git a/app/client/ui/Pages.ts b/app/client/ui/Pages.ts
index c9ff0c9c..0b678f36 100644
--- a/app/client/ui/Pages.ts
+++ b/app/client/ui/Pages.ts
@@ -3,6 +3,7 @@ import { duplicatePage } from "app/client/components/duplicatePage";
 import { GristDoc } from "app/client/components/GristDoc";
 import { PageRec } from "app/client/models/DocModel";
 import { urlState } from "app/client/models/gristUrlState";
+import { isHiddenTable } from 'app/client/models/isHiddenTable';
 import * as MetaTableModel from "app/client/models/MetaTableModel";
 import { find as findInTree, fromTableData, TreeItemRecord, TreeRecord,
          TreeTableData} from "app/client/models/TreeModel";
@@ -80,7 +81,11 @@ function buildDomFromTable(pagesTable: MetaTableModel<PageRec>, activeDoc: Grist
     actions.onRemove = () => confirmModal(
       `Delete ${pageName()} data, and remove it from all pages?`, 'Delete', doRemove);
 
-    actions.isRemoveDisabled = () => (docModel.allTables.all().length <= 1);
+    // Disable removing the last page. Sometimes hidden pages end up showing in the side panel
+    // (e.g. GristHidden_import* for aborted imports); those aren't listed in allTables, and we
+    // should allow removing them.
+    actions.isRemoveDisabled = () => (docModel.allTables.all().length <= 1) &&
+      !isHiddenTable(docModel.tables.tableData, tableRef);
   }
 
   return buildPageDom(fromKo(pageName), actions, urlState().setLinkUrl({docPage: viewId}));