Support href and cursor properties for marks

scripts/rename-schema.sh

@@ -12,6 +12,9 @@ perl -pi -e s,'GenericHConcatSpec<CompositeUnitSpec>','HConcatSpec',g build/vega
 perl -pi -e s,'GenericUnitSpec<EncodingWithFacet\,AnyMark>','FacetedCompositeUnitSpecAlias',g build/vega-lite-schema.json
 perl -pi -e s,'GenericUnitSpec<Encoding\,AnyMark>','CompositeUnitSpecAlias',g build/vega-lite-schema.json
 
+perl -pi -e s,'FieldDefWithCondition<FieldDef\>','FieldDefWithCondition',g build/vega-lite-schema.json
+perl -pi -e s,'ValueDefWithCondition<FieldDef\>','ValueDefWithCondition',g build/vega-lite-schema.json
+
 perl -pi -e s,'FieldDefWithCondition<TextFieldDef\>','TextFieldDefWithCondition',g build/vega-lite-schema.json
 perl -pi -e s,'ValueDefWithCondition<TextFieldDef\>','TextValueDefWithCondition',g build/vega-lite-schema.json
 

site/docs/encoding.md

@@ -30,6 +30,9 @@ The `encoding` property of a single view specification represents the mapping be
     "text": ...,
     "tooltip": ...,
 
+    // Hyperlink Channel
+    "href": ...,
+
     // Order Channel
     "order": ...,
 
@@ -51,7 +54,8 @@ The keys in the `encoding` object are encoding channels.  Vega-lite supports the
 
 - [Position Channels](#position): `x`, `y`, `x2`, `y2`
 - [Mark Property Channels](#mark-prop): `color`, `opacity`, `shape`, `size`
-- [Text and Tooltip Channels](#text):  `text`, `tooltip`
+- [Text and Tooltip Channels](#text): `text`, `tooltip`
+- [Hyperlink Channel](#href): `href`
 - [Level of Detail Channel](#detail): `detail`
 - [Order Channel](#order): `order`
 - [Facet Channels](#facet): `row`, `column`
@@ -204,6 +208,29 @@ In addition to the constant `value`, [value definitions](#value-def) of `text` a
 
 {% include table.html props="condition" source="TextValueDefWithCondition" %}
 
+{:#href}
+## Hyperlink Channel
+
+By setting the `href` channel, a mark becomes a hyperlink. The specified URL is loaded upon a muse click. The `cursor` mark property can be set to `pointer` to serve as affordance for hyperlinks.
+
+{% include table.html props="href" source="Encoding" %}
+
+
+{:#href-field-def}
+### Hyperlink Field Definition
+
+In addition to [`field`](field.html), [`type`](type.html), [`bin`](bin.html), [`timeUnit`](timeunit.html) and [`aggregate`](aggregate.html),
+[field definitions](#field-def) for the `href` channel can include the `condition` property to specify conditional logic.
+
+{% include table.html props="condition" source="FieldDefWithCondition" %}
+
+{:#href-value-def}
+### Hyperlink Value Definition
+
+In addition to the constant `value`, [value definitions](#value-def) of the `href` channel can include the `condition` property to specify conditional logic.
+
+{% include table.html props="condition" source="ValueDefWithCondition" %}
+
 
 {:#detail}
 ## Level of Detail Channel

site/docs/mark/mark.md

@@ -125,11 +125,16 @@ The rest of this section describe groups of properties supported by the `mark` c
 
 {% include table.html props="opacity,fillOpacity,strokeOpacity" source="MarkConfig" %}
 
-
 ### Stroke Style
 
 {% include table.html props="strokeWidth,strokeDash,strokeDashOffset" source="MarkConfig" %}
 
+### Link Properties
+
+Marks can act as hyperlinks when the `href` property is defined. A `cursor` property can also be provided to serve as affordance for the links.
+
+{% include table.html props="href,cursor" source="MarkConfig" %}
+
 <!-- one example for custom fill/stroke -->
 
 {:#interpolate}

src/channel.ts

@@ -32,6 +32,7 @@ export namespace Channel {
   export const ORDER: 'order' = 'order';
   export const DETAIL: 'detail' = 'detail';
   export const TOOLTIP: 'tooltip' = 'tooltip';
+  export const HREF: 'href' = 'href';
 }
 
 export type Channel = keyof Encoding<any> | keyof FacetMapping<any>;
@@ -50,6 +51,7 @@ export const DETAIL = Channel.DETAIL;
 export const ORDER = Channel.ORDER;
 export const OPACITY = Channel.OPACITY;
 export const TOOLTIP = Channel.TOOLTIP;
+export const HREF = Channel.HREF;
 
 const UNIT_CHANNEL_INDEX: Flag<keyof Encoding<any>> = {
   x: 1,
@@ -63,7 +65,8 @@ const UNIT_CHANNEL_INDEX: Flag<keyof Encoding<any>> = {
   opacity: 1,
   text: 1,
   detail: 1,
-  tooltip: 1
+  tooltip: 1,
+  href: 1,
 };
 
 const FACET_CHANNEL_INDEX: Flag<keyof FacetMapping<any>> = {
@@ -93,7 +96,7 @@ export const SINGLE_DEF_CHANNELS: SingleDefChannel[] = flagKeys(SINGLE_DEF_CHANN
 // Using the following line leads to TypeError: Cannot read property 'elementTypes' of undefined
 // when running the schema generator
 // export type SingleDefChannel = typeof SINGLE_DEF_CHANNELS[0];
-export type SingleDefChannel = 'x' | 'y' | 'x2' | 'y2' | 'row' | 'column' | 'size' | 'shape' | 'color' | 'opacity' | 'text' | 'tooltip';
+export type SingleDefChannel = 'x' | 'y' | 'x2' | 'y2' | 'row' | 'column' | 'size' | 'shape' | 'color' | 'opacity' | 'text' | 'tooltip' | 'href';
 
 
 
@@ -124,9 +127,9 @@ export type PositionScaleChannel = typeof POSITION_SCALE_CHANNELS[0];
 
 // NON_POSITION_SCALE_CHANNEL = SCALE_CHANNELS without X, Y
 const {
-    // x2 and y2 share the same scale as x and y
-  // text and tooltip has format instead of scale
-  text: _t, tooltip: _tt,
+  // x2 and y2 share the same scale as x and y
+  // text, tooltip, and href have format instead of scale
+  text: _t, tooltip: _tt, href: _hr,
   // detail and order have no scale
   detail: _dd, order: _oo,
   ...NONPOSITION_SCALE_CHANNEL_INDEX
@@ -159,7 +162,6 @@ export interface SupportedMark {
   line?: boolean;
   area?: boolean;
   text?: boolean;
-  tooltip?: boolean;
 }
 
 /**
@@ -184,6 +186,7 @@ export function getSupportedMark(channel: Channel): SupportedMark {
     case COLOR:
     case DETAIL:
     case TOOLTIP:
+    case HREF:
     case ORDER:    // TODO: revise (order might not support rect, which is not stackable?)
     case OPACITY:
     case ROW:
@@ -223,9 +226,10 @@ export function rangeType(channel: Channel): RangeType {
     case ROW:
     case COLUMN:
     case SHAPE:
-    // TEXT and TOOLTIP have no scale but have discrete output
+    // TEXT, TOOLTIP, and HREF have no scale but have discrete output
     case TEXT:
     case TOOLTIP:
+    case HREF:
       return 'discrete';
 
     // Color can be either continuous or discrete, depending on scale type.

src/compile/mark/area.ts

@@ -14,6 +14,7 @@ export const area: MarkCompiler = {
 
       ...mixins.color(model),
       ...mixins.text(model, 'tooltip'),
+      ...mixins.text(model, 'href'),
       ...mixins.nonPosition('opacity', model),
     };
   }

src/compile/mark/bar.ts

@@ -24,6 +24,7 @@ export const bar: MarkCompiler = {
       ...y(model, stack),
       ...mixins.color(model),
       ...mixins.text(model, 'tooltip'),
+      ...mixins.text(model, 'href'),
       ...mixins.nonPosition('opacity', model)
     };
   }

src/compile/mark/line.ts

@@ -15,6 +15,7 @@ export const line: MarkCompiler = {
       ...mixins.pointPosition('y', model, ref.mid(height)),
       ...mixins.color(model),
       ...mixins.text(model, 'tooltip'),
+      ...mixins.text(model, 'href'),
       ...mixins.nonPosition('opacity', model),
       ...mixins.nonPosition('size', model, {
         vgChannel: 'strokeWidth'  // VL's line size is strokeWidth

src/compile/mark/mark.ts

@@ -154,9 +154,10 @@ export function pathGroupingFields(encoding: Encoding<string>): string[] {
       case 'y':
       case 'order':
       case 'tooltip':
+      case 'href':
       case 'x2':
       case 'y2':
-      // TODO: case 'href', 'cursor':
+      // TODO: case 'cursor':
 
       // text, shape, shouldn't be a part of line/area
       case 'text':

src/compile/mark/mixins.ts

@@ -100,7 +100,7 @@ function wrapCondition(
   }
 }
 
-export function text(model: UnitModel, channel: 'text' | 'tooltip' = 'text') {
+export function text(model: UnitModel, channel: 'text' | 'tooltip' | 'href' = 'text') {
   const channelDef = model.encoding[channel];
   return wrapCondition(model, channelDef, channel, (cDef) => ref.text(cDef, model.config));
 }

src/compile/mark/point.ts

@@ -17,6 +17,7 @@ function encodeEntry(model: UnitModel, fixedShape?: 'circle' | 'square') {
 
     ...mixins.color(model),
     ...mixins.text(model, 'tooltip'),
+    ...mixins.text(model, 'href'),
     ...mixins.nonPosition('size', model),
     ...shapeMixins(model, config, fixedShape),
     ...mixins.nonPosition('opacity', model),

src/compile/mark/rect.ts

@@ -17,6 +17,7 @@ export const rect: MarkCompiler = {
       ...y(model),
       ...mixins.color(model),
       ...mixins.text(model, 'tooltip'),
+      ...mixins.text(model, 'href'),
       ...mixins.nonPosition('opacity', model),
     };
   }

src/compile/mark/rule.ts

@@ -23,6 +23,7 @@ export const rule: MarkCompiler = {
 
       ...mixins.color(model),
       ...mixins.text(model, 'tooltip'),
+      ...mixins.text(model, 'href'),
       ...mixins.nonPosition('opacity', model),
       ...mixins.nonPosition('size', model, {
         vgChannel: 'strokeWidth'  // VL's rule size is strokeWidth

src/compile/mark/text.ts

@@ -26,6 +26,7 @@ export const text: MarkCompiler = {
       ...mixins.text(model),
       ...mixins.color(model),
       ...mixins.text(model, 'tooltip'),
+      ...mixins.text(model, 'href'),
       ...mixins.nonPosition('opacity', model),
       ...mixins.nonPosition('size', model, {
         vgChannel: 'fontSize'  // VL's text size is fontSize

src/compile/mark/tick.ts

@@ -28,6 +28,8 @@ export const tick: MarkCompiler = {
       [vgThicknessChannel]: {value: config.tick.thickness},
 
       ...mixins.color(model),
+      ...mixins.text(model, 'tooltip'),
+      ...mixins.text(model, 'href'),
       ...mixins.nonPosition('opacity', model),
     };
   }

src/encoding.ts

@@ -98,6 +98,11 @@ export interface Encoding<F> {
    */
   tooltip?: FieldDefWithCondition<TextFieldDef<F>> | ValueDefWithCondition<TextFieldDef<F>>;
 
+  /**
+   * A URL to load upon mouse click.
+   */
+  href?: FieldDefWithCondition<FieldDef<F>> | ValueDefWithCondition<FieldDef<F>>;
+
   /**
    * Stack order for stacked marks or order of data points in line marks for connected scatter plots.
    *

src/fielddef.ts

@@ -535,6 +535,7 @@ export function channelCompatibility(fieldDef: FieldDef<Field>, channel: Channel
     case 'text':
     case 'detail':
     case 'tooltip':
+    case 'href':
       return COMPATIBLE;
 
     case 'opacity':

src/vega.schema.ts

@@ -193,7 +193,7 @@ export interface VgSignal {
   push?: string;
 }
 
-export type VgEncodeChannel = 'x'|'x2'|'xc'|'width'|'y'|'y2'|'yc'|'height'|'opacity'|'fill'|'fillOpacity'|'stroke'|'strokeWidth'|'strokeOpacity'|'strokeDash'|'strokeDashOffset'|'cursor'|'clip'|'size'|'shape'|'path'|'innerRadius'|'outerRadius'|'startAngle'|'endAngle'|'interpolate'|'tension'|'orient'|'url'|'align'|'baseline'|'text'|'dir'|'ellipsis'|'limit'|'dx'|'dy'|'radius'|'theta'|'angle'|'font'|'fontSize'|'fontWeight'|'fontStyle';
+export type VgEncodeChannel = 'x'|'x2'|'xc'|'width'|'y'|'y2'|'yc'|'height'|'opacity'|'fill'|'fillOpacity'|'stroke'|'strokeWidth'|'strokeOpacity'|'strokeDash'|'strokeDashOffset'|'cursor'|'clip'|'size'|'shape'|'path'|'innerRadius'|'outerRadius'|'startAngle'|'endAngle'|'interpolate'|'tension'|'orient'|'url'|'align'|'baseline'|'text'|'dir'|'ellipsis'|'limit'|'dx'|'dy'|'radius'|'theta'|'angle'|'font'|'fontSize'|'fontWeight'|'fontStyle'|'href'|'cursor';
 export type VgEncodeEntry = {
   [k in VgEncodeChannel]?: VgValueRef | (VgValueRef & {test?: string})[];
 };
@@ -1056,6 +1056,18 @@ export interface VgMarkConfig {
    * Placeholder text if the `text` channel is not specified
    */
   text?: string;
+
+  /**
+   * A URL to load upon mouse click. If defined, the mark acts as a hyperlink.
+   *
+   * @format uri
+   */
+  href?: string;
+
+  /**
+   * The mouse cursor used over the mark. Any valid [CSS cursor type](https://developer.mozilla.org/en-US/docs/Web/CSS/cursor#Values) can be used.
+   */
+  cursor?: 'auto' | 'default' | 'none' | 'context-menu' | 'help' | 'pointer' | 'progress' | 'wait' | 'cell' | 'crosshair' | 'text' | 'vertical-text' | 'alias' | 'copy' | 'move' | 'no-drop' | 'not-allowed' | 'e-resize' | 'n-resize' | 'ne-resize' | 'nw-resize' | 's-resize' | 'se-resize' | 'sw-resize' | 'w-resize' | 'ew-resize' | 'ns-resize' | 'nesw-resize' | 'nwse-resize' | 'col-resize' | 'row-resize' | 'all-scroll' | 'zoom-in' | 'zoom-out' | 'grab' | 'grabbing';
 }
 
 const VG_MARK_CONFIG_INDEX: Flag<keyof VgMarkConfig> = {
@@ -1084,17 +1096,18 @@ const VG_MARK_CONFIG_INDEX: Flag<keyof VgMarkConfig> = {
   font: 1,
   fontSize: 1,
   fontWeight: 1,
-  fontStyle: 1
+  fontStyle: 1,
+  cursor: 1,
+  href: 1,
   // commented below are vg channel that do not have mark config.
   // 'x'|'x2'|'xc'|'width'|'y'|'y2'|'yc'|'height'
-  // cursor: 1,
   // clip: 1,
   // dir: 1,
   // ellipsis: 1,
   // endAngle: 1,
-  // path: 1,
   // innerRadius: 1,
   // outerRadius: 1,
+  // path: 1,
   // startAngle: 1,
   // url: 1,
 };

test/channel.test.ts

@@ -18,7 +18,7 @@ describe('channel', () => {
 
   describe('SCALE_CHANNELS', () => {
     it('should be UNIT_CHANNELS without X2, Y2, ORDER, DETAIL, TEXT, LABEL, TOOLTIP', () => {
-      assert.deepEqual(SCALE_CHANNELS, without(UNIT_CHANNELS, ['x2', 'y2', 'order', 'detail', 'text', 'label', 'tooltip']));
+      assert.deepEqual(SCALE_CHANNELS, without(UNIT_CHANNELS, ['x2', 'y2', 'order', 'detail', 'text', 'label', 'tooltip', 'href']));
     });
   });
 

test/compile/mark/mark.test.ts

@@ -120,6 +120,21 @@ describe('Mark', function() {
         assert.equal(markGroup[0].encode.update.tooltip.value, 'foo');
       });
     });
+
+    describe('Bar with href', () => {
+      it('should pass href value to encoding', () => {
+        const model = parseUnitModelWithScaleAndLayoutSize({
+          "mark": "bar",
+          "encoding": {
+            "x": {"type": "quantitative", "field": "Cost__Other", "aggregate": "sum"},
+            "y": {"bin": true, "type": "quantitative", "field": "Cost__Total_$"},
+            "href": {"value": "https://idl.cs.washington.edu/"}
+          }
+        });
+        const markGroup = parseMarkGroup(model);
+        assert.equal(markGroup[0].encode.update.href.value, 'https://idl.cs.washington.edu/');
+      });
+    });
   });
 
   describe('getPathSort', () => {