(core) Add a row to summary tables grouped by list column(s) corresponding to empty lists

Summary:
Adds some special handling to summary table and lookup logic:

- Source rows with empty choicelists/reflists get a corresponding summary row with an empty string/reference when grouping by that column, instead of excluding them from any group
- Adds a new `QueryOperation` 'empty' in the client which is used in `LinkingState`, `QuerySet`, and `recursiveMoveToCursorPos` to match empty lists in source tables against falsy values in linked summary tables.
- Adds a new parameter `match_empty` to the Python `CONTAINS` function so that regular formulas can implement the same behaviour as summary tables. See https://grist.slack.com/archives/C0234CPPXPA/p1654030490932119
- Uses the new `match_empty` argument in the formula generated for the `group` column when detaching a summary table.

Test Plan: Updated and extended Python and nbrowser tests of summary tables grouped by choicelists to test for new behaviour with empty lists.

Reviewers: georgegevoian

Reviewed By: georgegevoian

Differential Revision: https://phab.getgrist.com/D3471

app/client/components/GristDoc.ts

@@ -55,7 +55,7 @@ import {CommDocUsage, CommDocUserAction} from 'app/common/CommTypes';
 import {DisposableWithEvents} from 'app/common/DisposableWithEvents';
 import {isSchemaAction, UserAction} from 'app/common/DocActions';
 import {OpenLocalDocResult} from 'app/common/DocListAPI';
-import {isList, isRefListType, RecalcWhen} from 'app/common/gristTypes';
+import {isList, isListType, isRefListType, RecalcWhen} from 'app/common/gristTypes';
 import {HashLink, IDocPage, isViewDocPage, SpecialDocPage, ViewDocPage} from 'app/common/gristUrls';
 import {undef, waitObs} from 'app/common/gutil';
 import {LocalPlugin} from "app/common/plugin";
@@ -856,9 +856,12 @@ export class GristDoc extends DisposableWithEvents {
             // must be a summary -- otherwise dealt with earlier.
             const destTable = await this._getTableData(section);
             for (const srcCol of srcSection.table.peek().groupByColumns.peek()) {
-              const filterColId = srcCol.summarySource.peek().colId.peek();
+              const filterCol = srcCol.summarySource.peek();
+              const filterColId = filterCol.colId.peek();
               controller = destTable.getValue(cursorPos.rowId, filterColId);
-              query.operations[filterColId] = 'in';
+              // If the source groupby column is a ChoiceList or RefList, then null or '' in the summary table
+              // should match against an empty list in the source table.
+              query.operations[filterColId] = isListType(filterCol.type.peek()) && !controller ? 'empty' : 'in';
               query.filters[filterColId] = isList(controller) ? controller.slice(1) : [controller];
             }
           }

app/client/components/LinkingState.ts

@@ -7,14 +7,14 @@ import {ViewSectionRec} from "app/client/models/entities/ViewSectionRec";
 import {RowId} from "app/client/models/rowset";
 import {LinkConfig} from "app/client/ui/selectBy";
 import {ClientQuery, QueryOperation} from "app/common/ActiveDocAPI";
-import {isList, isRefListType} from "app/common/gristTypes";
+import {isList, isListType, isRefListType} from "app/common/gristTypes";
 import * as gutil from "app/common/gutil";
 import {encodeObject} from 'app/plugin/objtypes';
 import {Disposable, toKo} from "grainjs";
 import * as  ko from "knockout";
+import identity = require('lodash/identity');
 import mapValues = require('lodash/mapValues');
 import pickBy = require('lodash/pickBy');
-import identity = require('lodash/identity');
 
 
 /**
@@ -124,18 +124,14 @@ export class LinkingState extends Disposable {
           const srcValue = srcTableData.getValue(srcRowId as number, colId);
           result.filters[colId] = [srcValue];
           result.operations[colId] = 'in';
-          if (isDirectSummary) {
+          if (isDirectSummary && isListType(col.type())) {
-            const tgtColType = col.type();
+            // If the source groupby column is a ChoiceList or RefList, then null or '' in the summary table
-            if (tgtColType === 'ChoiceList' || tgtColType.startsWith('RefList:')) {
+            // should match against an empty list in the source table.
-              result.operations[colId] = 'intersects';
+            result.operations[colId] = srcValue ? 'intersects' : 'empty';
-            }
           }
         }
         _filterColValues(result);
       }
-    } else if (isSummaryOf(tgtSection.table(), srcSection.table())) {
-      // TODO: We should move the cursor, but don't currently it for summaries. For that, we need a
-      // column or map representing the inverse of summary table's "group" column.
     } else if (srcSection.parentKey() === 'custom') {
       this.filterColValues = this._srcCustomFilter('id', 'in');
     } else {

app/client/models/QuerySet.ts

@@ -33,16 +33,16 @@ import {TableData} from 'app/client/models/TableData';
 import {ActiveDocAPI, ClientQuery, QueryOperation} from 'app/common/ActiveDocAPI';
 import {CellValue, TableDataAction} from 'app/common/DocActions';
 import {DocData} from 'app/common/DocData';
+import {isList} from "app/common/gristTypes";
 import {nativeCompare} from 'app/common/gutil';
 import {IRefCountSub, RefCountMap} from 'app/common/RefCountMap';
-import {TableData as BaseTableData} from 'app/common/TableData';
 import {RowFilterFunc} from 'app/common/RowFilterFunc';
+import {TableData as BaseTableData} from 'app/common/TableData';
 import {tbind} from 'app/common/tbind';
+import {decodeObject} from "app/plugin/objtypes";
 import {Disposable, Holder, IDisposableOwnerT} from 'grainjs';
 import * as ko from 'knockout';
 import debounce = require('lodash/debounce');
-import {isList} from "app/common/gristTypes";
-import {decodeObject} from "app/plugin/objtypes";
 
 // Limit on the how many rows to request for OnDemand tables.
 const ON_DEMAND_ROW_LIMIT = 10000;
@@ -310,17 +310,21 @@ export function getFilterFunc(docData: DocData, query: ClientQuery): RowFilterFu
     (colId) => {
       const getter = tableData.getRowPropFunc(colId)!;
       const values = new Set(query.filters[colId]);
-      switch (query.operations![colId]) {
+      switch (query.operations[colId]) {
         case "intersects":
           return (rowId: RowId) => {
             const value = getter(rowId) as CellValue;
             return isList(value) &&
               (decodeObject(value) as unknown[]).some(v => values.has(v));
           };
+        case "empty":
+          return (rowId: RowId) => {
+            const value = getter(rowId);
+            // `isList(value) && value.length === 1` means `value == ['L']` i.e. an empty list
+            return !value || isList(value) && value.length === 1;
+          };
         case "in":
           return (rowId: RowId) => values.has(getter(rowId));
-        default:
-          throw new Error("Unknown operation");
       }
     });
   return (rowId: RowId) => colFuncs.every(f => f(rowId));
@@ -342,7 +346,7 @@ function convertQueryToRefs(docModel: DocModel, query: ClientQuery): QueryRefs {
     const values = query.filters[colId];
     // Keep filter values sorted by value, for consistency.
     values.sort(nativeCompare);
-    return [colRefsByColId[colId], query.operations![colId], values] as FilterTuple;
+    return [colRefsByColId[colId], query.operations[colId], values] as FilterTuple;
   });
   // Keep filters sorted by colRef, for consistency.
   filterTuples.sort((a, b) =>

app/common/ActiveDocAPI.ts

@@ -121,7 +121,10 @@ export interface QueryFilters {
   [colId: string]: any[];
 }
 
-export type QueryOperation = "in" | "intersects";
+// - in: value should be contained in filters array
+// - intersects: value should be a list with some overlap with filters array
+// - empty: value should be falsy (e.g. null) or an empty list, filters is ignored
+export type QueryOperation = "in" | "intersects" | "empty";
 
 /**
  * Response from useQuerySet(). A query returns data AND creates a subscription to receive

sandbox/grist/docmodel.py

@@ -9,10 +9,10 @@ import itertools
 
 import six
 
+import functions
 import records
 import usertypes
 import relabeling
-import lookup
 import table
 import moment
 from schema import RecalcWhen
@@ -31,7 +31,7 @@ def _record_ref_list_set(table_id, group_by, sort_by=None):
   @usertypes.formulaType(usertypes.ReferenceList(table_id))
   def func(rec, table):
     lookup_table = table.docmodel.get_table(table_id)
-    return lookup_table.lookupRecords(sort_by=sort_by, **{group_by: lookup._Contains(rec.id)})
+    return lookup_table.lookupRecords(sort_by=sort_by, **{group_by: functions.CONTAINS(rec.id)})
   return func
 
 

sandbox/grist/functions/lookup.py

@@ -151,7 +151,17 @@ def VLOOKUP(table, **field_value_pairs):
   """
   return table.lookupOne(**field_value_pairs)
 
-class _Contains(namedtuple("_Contains", "value")):
+
+class _NoMatchEmpty(object):
+  """
+  Singleton sentinel value for CONTAINS match_empty parameter to indicate no argument was passed
+  and no value should match against empty lists in lookups.
+  """
+  def __repr__(self):
+    return "no_match_empty"
+
+
+class _Contains(namedtuple("_Contains", "value match_empty")):
   """
   Use this marker with [UserTable.lookupRecords](#lookuprecords) to find records
   where a field of a list type (such as `Choice List` or `Reference List`) contains the given value.
@@ -169,6 +179,16 @@ class _Contains(namedtuple("_Contains", "value")):
   In particular the values mustn't be strings, e.g. `"Comedy-Drama"` won't match
   even though `"Drama" in "Comedy-Drama"` is `True` in Python.
   It also won't match substrings within container elements, e.g. `["Comedy-Drama"]`.
+
+  You can optionally pass a second argument `match_empty` to indicate a value that
+  should be matched against empty lists in the looked up column.
+
+  For example, given this formula:
+
+      MoviesTable.lookupRecords(genre=CONTAINS(g, match_empty=''))
+
+  If `g` is `''` (i.e. equal to `match_empty`) then the column `genre` in the returned records
+  will either be an empty list (or other container) or a list containing `g` as usual.
   """
   # While users should apply this marker to values in queries, internally
   # the marker is moved to the column ID so that the LookupMapColumn knows how to
@@ -177,9 +197,16 @@ class _Contains(namedtuple("_Contains", "value")):
   # The CONTAINS function is for users
   # Having a function as the interface makes things like docs and autocomplete
   # work more consistently
-  pass
 
-def CONTAINS(value):
+  no_match_empty = _NoMatchEmpty()
-  return _Contains(value)
+
+
+def CONTAINS(value, match_empty=_Contains.no_match_empty):
+  try:
+    hash(match_empty)
+  except TypeError:
+    raise TypeError("match_empty must be hashable")
+
+  return _Contains(value, match_empty)
 
 CONTAINS.__doc__ = _Contains.__doc__

sandbox/grist/lookup.py

@@ -198,6 +198,8 @@ class ContainsLookupMapColumn(BaseLookupMapColumn):
         # group = [] essentially means there are no new keys in this call
         if isinstance(group, (six.binary_type, six.text_type)):
           group = []
+        elif not group and col_id.match_empty != _Contains.no_match_empty:
+          group = [col_id.match_empty]
       else:
         group = [group]
 

sandbox/grist/summary.py

@@ -388,9 +388,11 @@ class SummaryActions(object):
     group_args = ', '.join(
       '%s=%s' % (
         c.summarySourceCol.colId,
-        'CONTAINS($%s)' % c.colId
+        (
-        if c.summarySourceCol.type.startswith(('ChoiceList', 'RefList:')) else
+          'CONTAINS($%s, match_empty="")' if c.summarySourceCol.type == 'ChoiceList' else
-        '$%s' % c.colId,
+          'CONTAINS($%s, match_empty=0)' if c.summarySourceCol.type.startswith('Reflist') else
+          '$%s'
+        ) % c.colId,
       )
       for c in field_col_recs if c.summarySourceCol
     )

sandbox/grist/table.py

@@ -8,6 +8,7 @@ from six.moves import xrange
 import column
 import depend
 import docmodel
+import functions
 import logger
 import lookup
 import records
@@ -336,8 +337,8 @@ class Table(object):
         lookup_values = []
         for group_col in groupby_cols:
           lookup_value = getattr(rec, group_col)
-          if isinstance(self.all_columns[group_col],
+          group_col_obj = self.all_columns[group_col]
-                        (column.ChoiceListColumn, column.ReferenceListColumn)):
+          if isinstance(group_col_obj, (column.ChoiceListColumn, column.ReferenceListColumn)):
             # Check that ChoiceList/ReferenceList cells have appropriate types.
             # Don't iterate over characters of a string.
             if isinstance(lookup_value, (six.binary_type, six.text_type)):
@@ -347,6 +348,13 @@ class Table(object):
               lookup_value = set(lookup_value)
             except TypeError:
               return []
+
+            if not lookup_value:
+              if isinstance(group_col_obj, column.ChoiceListColumn):
+                lookup_value = {""}
+              else:
+                lookup_value = {0}
+
           else:
             lookup_value = [lookup_value]
           lookup_values.append(lookup_value)
@@ -459,11 +467,11 @@ class Table(object):
     for col_id in sorted(kwargs):
       value = kwargs[col_id]
       if isinstance(value, lookup._Contains):
-        value = value.value
         # While users should use CONTAINS on lookup values,
         # the marker is moved to col_id so that the LookupMapColumn knows how to
         # update its index correctly for that column.
-        col_id = lookup._Contains(col_id)
+        col_id = value._replace(value=col_id)
+        value = value.value
       else:
         col = self.get_column(col_id)
         # Convert `value` to the correct type of rich value for that column
@@ -527,7 +535,7 @@ class Table(object):
       # _summary_source_table._summary_simple determines whether
       # the column named self._summary_helper_col_id is a single reference
       # or a reference list.
-      lookup_value = rec if self._summary_simple else lookup._Contains(rec)
+      lookup_value = rec if self._summary_simple else functions.CONTAINS(rec)
       return self._summary_source_table.lookup_records(**{
         self._summary_helper_col_id: lookup_value
       })

sandbox/grist/test_summary_choicelist.py

@@ -142,10 +142,10 @@ class TestSummaryChoiceList(EngineTestCase):
       {k: type(v) for k, v in self.engine.tables["Source"]._special_cols.items()},
       {
         '#summary#GristSummary_6_Source': column.ReferenceListColumn,
-        "#lookup#_Contains(value='#summary#GristSummary_6_Source')":
+        "#lookup#_Contains(value='#summary#GristSummary_6_Source', match_empty=no_match_empty)":
           lookup.ContainsLookupMapColumn,
         '#summary#GristSummary_6_Source2': column.ReferenceListColumn,
-        "#lookup#_Contains(value='#summary#GristSummary_6_Source2')":
+        "#lookup#_Contains(value='#summary#GristSummary_6_Source2', match_empty=no_match_empty)":
           lookup.ContainsLookupMapColumn,
 
         # simple summary and lookup
@@ -153,7 +153,7 @@ class TestSummaryChoiceList(EngineTestCase):
         '#lookup##summary#GristSummary_6_Source3': lookup.SimpleLookupMapColumn,
 
         '#summary#GristSummary_6_Source4': column.ReferenceListColumn,
-        "#lookup#_Contains(value='#summary#GristSummary_6_Source4')":
+        "#lookup#_Contains(value='#summary#GristSummary_6_Source4', match_empty=no_match_empty)":
           lookup.ContainsLookupMapColumn,
 
         "#lookup#": lookup.SimpleLookupMapColumn,
@@ -203,6 +203,33 @@ class TestSummaryChoiceList(EngineTestCase):
       [5, "a", "e", [21], 1],
     ])
 
+    # Empty choices1
+    self.update_record("Source", 21, choices1=None)
+
+    self.assertTableData('Source', data=[
+      ["id", "choices1", "choices2", "other"],
+      [21, None, ["c", "d", "e"], "foo"],
+    ])
+
+    self.assertTableData('GristSummary_6_Source', data=[
+      ["id", "choices1", "group", "count"],
+      [1, "a", [], 0],
+      [2, "b", [], 0],
+      [3, "", [21], 1],
+    ])
+
+    self.assertTableData('GristSummary_6_Source2', data=[
+      ["id", "choices1", "choices2", "group", "count"],
+      [1, "a", "c", [], 0],
+      [2, "a", "d", [], 0],
+      [3, "b", "c", [], 0],
+      [4, "b", "d", [], 0],
+      [5, "a", "e", [], 0],
+      [6, "", "c", [21], 1],
+      [7, "", "d", [21], 1],
+      [8, "", "e", [21], 1],
+    ])
+
     # Remove record from source
     self.remove_record("Source", 21)
 
@@ -211,6 +238,7 @@ class TestSummaryChoiceList(EngineTestCase):
       ["id", "choices1", "group", "count"],
       [1, "a", [], 0],
       [2, "b", [], 0],
+      [3, "", [], 0],
     ])
 
     self.assertTableData('GristSummary_6_Source2', data=[
@@ -220,6 +248,9 @@ class TestSummaryChoiceList(EngineTestCase):
       [3, "b", "c", [], 0],
       [4, "b", "d", [], 0],
       [5, "a", "e", [], 0],
+      [6, "",  "c", [], 0],
+      [7, "",  "d", [], 0],
+      [8, "",  "e", [], 0],
     ])
 
     # Make rows with every combination of {a,b,ab} and {c,d,cd}
@@ -236,6 +267,8 @@ class TestSummaryChoiceList(EngineTestCase):
         [107, ["L", "a"],      ["L", "c", "d"]],
         [108, ["L", "b"],      ["L", "c", "d"]],
         [109, ["L", "a", "b"], ["L", "c", "d"]],
+        # and one row with empty lists
+        [110, ["L"],           ["L"]],
       ]
     )
 
@@ -250,6 +283,7 @@ class TestSummaryChoiceList(EngineTestCase):
       [107, ["a"],      ["c", "d"]],
       [108, ["b"],      ["c", "d"]],
       [109, ["a", "b"], ["c", "d"]],
+      [110, None,       None],
     ])
 
     # Summary tables now have an even distribution of combinations
@@ -257,6 +291,7 @@ class TestSummaryChoiceList(EngineTestCase):
       ["id", "choices1", "group", "count"],
       [1, "a", [101, 103, 104, 106, 107, 109], 6],
       [2, "b", [102, 103, 105, 106, 108, 109], 6],
+      [3, "",  [110], 1],
     ])
 
     summary_data = [
@@ -266,6 +301,10 @@ class TestSummaryChoiceList(EngineTestCase):
       [3, "b", "c", [102, 103, 108, 109], 4],
       [4, "b", "d", [105, 106, 108, 109], 4],
       [5, "a", "e", [], 0],
+      [6, "", "c", [], 0],
+      [7, "", "d", [], 0],
+      [8, "", "e", [], 0],
+      [9, "", "", [110], 1],
     ]
 
     self.assertTableData('GristSummary_6_Source2', data=summary_data)
@@ -284,8 +323,9 @@ class TestSummaryChoiceList(EngineTestCase):
           Column(30, "count", "Int", isFormula=True, summarySourceCol=0,
                  formula="len($group)"),
           Column(31, "group", "RefList:Source", isFormula=True, summarySourceCol=0,
-                 formula="Source.lookupRecords(choices1=CONTAINS($choices1), choices2=CONTAINS($choices2))"),
+                 formula='Source.lookupRecords('
-
+                         'choices1=CONTAINS($choices1, match_empty=""), '
+                         'choices2=CONTAINS($choices2, match_empty=""))'),
         ],
       )
     ])