fix: interval selection should gracefully fail if no valid projections

build/vega-lite-schema.json

@@ -11959,13 +11959,6 @@
           },
           "type": "array"
         },
-        "fields": {
-          "description": "An array of field names whose values must match for a data tuple to fall within the selection.\n\n__See also:__ The [projection with `encodings` and `fields` section](https://vega.github.io/vega-lite/docs/selection.html#project) in the documentation.",
-          "items": {
-            "$ref": "#/definitions/FieldName"
-          },
-          "type": "array"
-        },
         "mark": {
           "$ref": "#/definitions/BrushConfig",
           "description": "An interval selection also adds a rectangle mark to depict the extents of the interval. The `mark` property can be used to customize the appearance of the mark.\n\n__See also:__ [`mark` examples](https://vega.github.io/vega-lite/docs/selection.html#mark) in the documentation."
@@ -12034,13 +12027,6 @@
           },
           "type": "array"
         },
-        "fields": {
-          "description": "An array of field names whose values must match for a data tuple to fall within the selection.\n\n__See also:__ The [projection with `encodings` and `fields` section](https://vega.github.io/vega-lite/docs/selection.html#project) in the documentation.",
-          "items": {
-            "$ref": "#/definitions/FieldName"
-          },
-          "type": "array"
-        },
         "mark": {
           "$ref": "#/definitions/BrushConfig",
           "description": "An interval selection also adds a rectangle mark to depict the extents of the interval. The `mark` property can be used to customize the appearance of the mark.\n\n__See also:__ [`mark` examples](https://vega.github.io/vega-lite/docs/selection.html#mark) in the documentation."

site/_includes/docs_toc.md

@@ -285,7 +285,6 @@
         - [Nominal]({{site.baseurl}}/docs/type.html#nominal)
         - [GeoJSON]({{site.baseurl}}/docs/type.html#geojson)
     - [Value]({{site.baseurl}}/docs/value.html)
-        - [Examples]({{site.baseurl}}/docs/value.html#examples)
 - [Projection]({{site.baseurl}}/docs/projection.html)
     - [Documentation Overview]({{site.baseurl}}/docs/projection.html#documentation-overview)
     - [Projection Properties]({{site.baseurl}}/docs/projection.html#projection-properties)
@@ -328,7 +327,6 @@
     - [Using Parameters]({{site.baseurl}}/docs/parameter.html#using-parameters)
     - [Selection Configuration]({{site.baseurl}}/docs/parameter.html#config)
     - [Value]({{site.baseurl}}/docs/value.html)
-        - [Examples]({{site.baseurl}}/docs/value.html#examples)
     - [Expr]({{site.baseurl}}/docs/parameter.html)
         - [Documentation Overview]({{site.baseurl}}/docs/parameter.html#documentation-overview)
         - [Defining a Parameter]({{site.baseurl}}/docs/parameter.html#defining-a-parameter)

src/compile/selection/interval.ts

@@ -68,7 +68,7 @@ const interval: SelectionCompiler<'interval'> = {
 
     // Proxy scale reactions to ensure that an infinite loop doesn't occur
     // when an interval selection filter touches the scale.
-    if (!hasScales) {
+    if (!hasScales && scaleTriggers.length) {
       signals.push({
         name: name + SCALE_TRIGGER,
         value: {},
@@ -88,12 +88,16 @@ const interval: SelectionCompiler<'interval'> = {
     return signals.concat({
       name: name + TUPLE,
       ...(init ? {init: `{${update}: ${assembleInit(init)}}`} : {}),
-      on: [
-        {
-          events: [{signal: dataSignals.join(' || ')}], // Prevents double invocation, see https://github.com/vega/vega#1672.
-          update: `${dataSignals.join(' && ')} ? {${update}: [${dataSignals}]} : null`
-        }
-      ]
+      ...(dataSignals.length
+        ? {
+            on: [
+              {
+                events: [{signal: dataSignals.join(' || ')}], // Prevents double invocation, see https://github.com/vega/vega#1672.
+                update: `${dataSignals.join(' && ')} ? {${update}: [${dataSignals}]} : null`
+              }
+            ]
+          }
+        : {})
     });
   },
 
@@ -104,8 +108,9 @@ const interval: SelectionCompiler<'interval'> = {
     const yvname = y && y.signals.visual;
     const store = `data(${stringValue(selCmpt.name + STORE)})`;
 
-    // Do not add a brush if we're binding to scales.
-    if (scales.defined(selCmpt)) {
+    // Do not add a brush if we're binding to scales
+    // or we don't have a valid interval projection
+    if (scales.defined(selCmpt) || (!x && !y)) {
       return marks;
     }
 

src/compile/selection/parse.ts

@@ -26,9 +26,14 @@ export function parseUnitSelection(model: UnitModel, selDefs: SelectionParameter
     // Set default values from config if a property hasn't been specified,
     // or if it is true. E.g., "translate": true should use the default
     // event handlers for translate. However, true may be a valid value for
-    // a property (e.g., "nearest": true). Project transform applies its defaults.
-    const {fields, encodings, ...cfg} = selectionConfig[type];
+    // a property (e.g., "nearest": true).
+    const cfg = selectionConfig[type];
     for (const key in cfg) {
+      // Project transform applies its defaults.
+      if (key === 'fields' || key === 'encodings') {
+        continue;
+      }
+
       if (key === 'mark') {
         defaults[key] = {...cfg[key], ...defaults[key]};
       }

src/compile/selection/project.ts

@@ -2,7 +2,7 @@ import {array, isObject} from 'vega-util';
 import {isSingleDefUnitChannel, ScaleChannel, SingleDefUnitChannel} from '../../channel';
 import * as log from '../../log';
 import {hasContinuousDomain} from '../../scale';
-import {BaseSelectionConfig, SelectionInitIntervalMapping, SelectionInitMapping} from '../../selection';
+import {PointSelectionConfig, SelectionInitIntervalMapping, SelectionInitMapping} from '../../selection';
 import {Dict, hash, keys, replacePathInField, varName, isEmpty} from '../../util';
 import {TimeUnitComponent, TimeUnitNode} from '../data/timeunit';
 import {SelectionCompiler} from '.';
@@ -71,7 +71,7 @@ const project: SelectionCompiler = {
 
     // If no explicit projection (either fields or encodings) is specified, set some defaults.
     // If an initial value is set, try to infer projections.
-    let {fields, encodings} = isObject(selDef.select) ? selDef.select : ({} as BaseSelectionConfig);
+    let {fields, encodings} = (isObject(selDef.select) ? selDef.select : {}) as PointSelectionConfig;
     if (!fields && !encodings && init) {
       for (const initVal of init) {
         // initVal may be a scalar value to smoothen varParam -> pointSelection gradient.
@@ -99,7 +99,9 @@ const project: SelectionCompiler = {
     // to account for unprojected point selections that have scalar initial values
     if (!fields && !encodings) {
       encodings = cfg.encodings;
-      fields = cfg.fields;
+      if ('fields' in cfg) {
+        fields = cfg.fields;
+      }
     }
 
     for (const channel of encodings ?? []) {
@@ -156,7 +158,6 @@ const project: SelectionCompiler = {
       }
     }
 
-    // TODO: find a possible channel mapping for these fields.
     for (const field of fields ?? []) {
       if (proj.hasField[field]) continue;
       const p: SelectionProjection = {type: 'E', field};

src/selection.ts

@@ -73,17 +73,17 @@ export interface BaseSelectionConfig<T extends SelectionType = SelectionType> {
    * __See also:__ The [projection with `encodings` and `fields` section](https://vega.github.io/vega-lite/docs/selection.html#project) in the documentation.
    */
   encodings?: SingleDefUnitChannel[];
+}
 
+export interface PointSelectionConfig extends BaseSelectionConfig<'point'> {
   /**
    * An array of field names whose values must match for a data tuple to
    * fall within the selection.
    *
    * __See also:__ The [projection with `encodings` and `fields` section](https://vega.github.io/vega-lite/docs/selection.html#project) in the documentation.
    */
   fields?: FieldName[];
-}
 
-export interface PointSelectionConfig extends BaseSelectionConfig<'point'> {
   /**
    * Controls whether data values should be toggled (inserted or removed from a point selection)
    * or only ever inserted into multi selections.