README

@visa/heat-map

An image depicting an example of the default heat-map component

<heat-map
  accessibility = {...}
  data = {[{"date":"2016-01-01T00:00:00.000Z","category":"Restaurant","value":120,"count":420},{data}]}
  valueAccessor = {"value"}
  xAccessor = {"date"}
  yAccessor = {"category"}
/>

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Installation Steps
Props Documentation

# Installation Steps

Using npm
```
$ npm i @visa/heat-map
```
Using yarn
```
$ yarn add @visa/heat-map
```

# Props Documentation

# Base Props <>

Name	Type	Default Value(s)	Description
`height`	number	250	Height in px of the chart container
`width`	number	500	Width in px of the chart container
`mainTitle`	string	'Heat Map Title'	The `dynamic` tag of title for the chart (or you can create your own separately). See `highestHeadingLevel` prop for how tags get assigned.
`subTitle`	string	'This is the heat map's subtitle'	The `dynamic` tag for a sub title for the chart (or you can create your own separately). See `highestHeadingLevel` prop for how tags get assigned.
`highestHeadingLevel`	string/number	'h2'	Sets the heading level (which also sets sublevels) for the chart. "p", "span", and "div" are also valid.

# Data Props <>

Name	Type	Default Value(s)	Description
`xAccessor`	string	'date'	Key used to determine the x-axis categorical value.
`yAccessor`	string	'category'	Key used to determine the y-axis categorical value.
`valueAccessor`	string	'value'	Key used to determine heatmap's numeric property, for assigning color.
`uniqueID`	string	`undefined`	ID used to identify chart (must be unique per chart), helpful for validation messages. Defaults to UUID v4 standard.
`data`	object[]	`undefined`	Data used to create chart, an array of objects which includes keys that map to above accessors.
`xKeyOrder`	string[]	`undefined`	Determines the order of x-axis categorical values.
`yKeyOrder`	string[]	`undefined`	Determines the order of y-axis categorical values.

# Accessibility Props <>

Name	Type	Default Value(s)	Description
`accessibility`	object (custom type)	IAccessibilityType	Manages messages and settings for chart accessibility, see object definition below.

IAccessibilityType Definition

Name (accessibility.)	Type	Default Value(s)	Description
`longDescription`	string	''	Use this to add a helpful description of the chart.
`executiveSummary`	string	''	Use this to describe the biggest takeaway of the chart.
`purpose`	string	''	Use this to describe the purpose of this particular chart.
`contextExplanation`	string	''	Use this to explain any controls or content on your page that affect or are affected by this chart.
`title`	string	''	Gives the chart an alternate title to be used by screen readers.
`elementDescriptionAccessor`	string	''	Optional key used to add an additional description to any element, from your data.
`statisticalNotes`	string	''	Use this to provide any statistical explanations, such as trends, clusters, patterns, or outliers.
`structureNotes`	string	''	Use this to describe special visual features of the chart, such as sorting, color grouping, etc.
`includeDataKeyNames`	boolean	false	If true, includes data key names in voice over description of each element. EG "Year over year growth: 5.6%" instead of just "5.6%"
`hideDataTableButton`	boolean	false	If true, hides the data table button (but it is still available to screen reader users).
`disableValidation`	boolean	false	If true, disables validations of accessibility props for this chart. Validation is intended to be used during development; upon completion, validation should be disabled.
`elementsAreInterface`	any/boolean	null	Defaults to null. Set to true if interacting with the elements in this chart affects your application. Otherwise, must be set to false.
`onChangeFunc`	function	`undefined`	Custom event listener (changeFunc) that enables dev to control accessibility page experience when chart data updates.
`showSmallLabels`	boolean	false	Defaults to false. Set to true if you would like to display labels on small elements that are likely to overlap. Note, this could impact accessibility of your graphic.
`hideStrokes`	boolean	false	Defaults to false. Set to true if you would like to remove automated stroke outlines from the chart, note, this could impact accessibility of your graphic.
`hideTextures`	boolean	false	Defaults to false. Set to true if you would like to remove textures from the chart, note, this could impact accessibility of your graphic.
`keyboardNavConfig`	IKeyConfig	`{ disabled: false }`	Defaults disabled to false. May be set to true if `accessibility.elementsAreInterface = false` and `suppressEvents = true`. This will disable keyboard navigation and simplify chart instructions for screen reader users.
`showExperimentalTextures`	boolean	false	Defaults to false. Set to true if you would like leverage our textures which are still undergoing research and development.

// accessibility = { ...accessibility, onChangeFunc: d => changeHandler(d)}
// example of setting updates on page based on changeFunc custom events
const changeHandler = d => {
  if (d.updated && (d.removed || d.added)) {
    let updates = 'The heat map has ';
    if (d.removed) {
      updates += 'removed ' + d.removed + ' grid element' + (d.removed > 1 ? 's ' : ' ');
    }
    if (d.added) {
      updates +=
        (d.removed ? 'and ' : '') +
        'added ' +
        d.added +
        (d.removed ? '' : d.added > 1 ? ' grid elements' : ' grid element');
    }
    setChartUpdates(updates);
  } else if (d.updated) {
    const newUpdate = "The chart's data has changed, but no grid elements were removed or added.";
    setChartUpdates(
      newUpdate !== chartUpdates
        ? newUpdate
        : "The chart's data has changed again, but no grid elements were removed or added."
    );
  }
};

# Annotation Props <>

Name	Type	Default Value(s)	Description
`annotations`	array[{annotations}]	[]	Adds annotations to the chart, see d3-svg-annotation by Susie Lu.

annotations object definition

annotations is an array of objects which needs to have the following properties within them. See the detailed api specifications from d3-svg-annotation, along with additional properties layered on top of that work, documented below.

Name	Type	Default Value(s)	Description
`accessibilityDescription`	string	`undefined`	Sets the accessibility description for the annotation for screen reader users.

# Axis Props <>

Name	Type	Default Value(s)	Description
`xAxis`	object (custom type)	IAxisType	Manages settings for the chart's x axis, see object definition below.
`yAxis`	object (custom type)	IAxisType	Manages settings for the chart's y axis, see object definition below.
`minValueOverride`	number	`undefined`	Overrides the calculated default min value.
`maxValueOverride`	number	`undefined`	Overrides the calculated default max value.
`hideAxisPath`	boolean	false	Controls the visibility axis path.
`wrapLabel`	boolean	true	When selected, wraps axis labels.

IAxisType Definition

Name (xAxis./yAxis.)	Type	Default Value(s)	Description
`visible`	boolean	true	Toggles the visibility of the axis.
`gridVisible`	boolean	true	Toggles the visibility of the axis grid.
`label`	string	'X Axis'	Sets the label for the axis.
`format`	string	'' or '%b %y' or '0[.][0][0]a'	Sets the formatting for axis elements, EG %b, refer to d3-time-format and numeral.js.
`tickInterval`	number	1	Can be used to reduce the frequency of axis ticks. This number sets the interval of axis ticks that are shown.

# Event Props <>

Events in stencil.js dispatch Custom DOM events for other components to handle, we use Stencil's @Event() decorator to emit events (click, hover, mouseOut) from end user activity on our charts.

Name	Type	Default Value(s)	Description
`suppressEvents`	boolean	false	Suppresses and disables click, hover and mouseOut event emitters. Setting to true can increase performance for non-interactive charts.
`cursor`	string	'default'	Changes pointer type during mouse over on elements. Valid values are 'default' or 'pointer'.
`onClickEvent`	function	`undefined`	When clickEvent event occurs (e.g., mouse/keyboard click on chart geometry), this event handler will be called with the custom event object (e.g., e), containing data and target node at e.detail `{data: d, target: n}`. You will need to construct your own functionality of what actions to take within the callback.
`clickHighlight`	object[]	[]	Data used to track chart selections, an array of objects which includes keys that map to above accessors.
`clickStyle`	object (custom type)	IClickStyleType	Sets the styling of elements when they are selected, see object definition below.
`onHoverEvent`	function	`undefined`	When hoverEvent event occurs (e.g., mouse hover/keyboard focus on chart geometry), this event handler will be called with the custom event object (e.g., e), containing data and target node at e.detail `{data: d, target: n}`. You will need to construct your own functionality of what actions to take within the callback.
`onMouseOutEvent`	function	`undefined`	When mouseOutEvent event occurs (e.g., mouse/keyboard blur on chart geometry), this event handler will be called, and has no data object. You will need to construct your own functionality of what actions to take within the callback.
`hoverHighlight`	object	{}	Datum object used to track active chart element, the object should include keys that map to above accessors.
`hoverStyle`	object (custom type)	IHoverStyleType	Sets the styling of elements when they are hovered/focused, see object definition below.
`interactionKeys`	string[]	[]	Sets the column names of data to interact with.
`hoverOpacity`	number	1	Sets opacity of inactive elements when hovering/focused on a chart geometry.
`onInitialLoadEvent`	function	`undefined`	When initalLoad event occurs (e.g., chart is mounted to window), this event handler will be called with the custom event object (e.g., e), containing the corresponding chartID at e.detail. You will need to construct your own functionality of what actions to take within the callback.
`onDrawStartEvent`	function	`undefined`	When drawStart event occurs (e.g., chart render function is called), this event handler will be called with the custom event object (e.g., e), containing the corresponding chartID at e.detail. You will need to construct your own functionality of what actions to take within the callback.
`onDrawEndEvent`	function	`undefined`	When drawEnd event occurs (e.g., chart's stencil lifecycle completes), this event handler will be called with the custom event object (e.g., e), containing the corresponding chartID at e.detail. You will need to construct your own functionality of what actions to take within the callback.
`onTransitionEndEvent`	function	`undefined`	When transitionEnd event occurs (e.g., chart geometry's transition lifecycle completes), this event handler will be called with the custom event object (e.g., e), containing the corresponding chartID at e.detail. You will need to construct your own functionality of what actions to take within the callback.

IClickStyleType Definition

Name	Type	Default Value(s)	Description
`color`	string	''	Sets the color of the clicked element (requires clickHighlight to be valid and sent).
`strokeWidth`	number	2	Sets the stroke width of the clicked element (requires clickHighlight to be valid and sent).

IHoverStyleType Definition

Name	Type	Default Value(s)	Description
`color`	string	''	Sets the color of the hovered element (requires hoverHighlight to be valid and sent).
`strokeWidth`	number	2	Sets the stroke width of the hovered element (requires hoverHighlight to be valid and sent).

// example of interactivity code
// note this only tracks a single click, you need your own logic to build the array of currnet selections made by user and then pass that result back to chart
//...
const clickHandler = evt => {
  const d = evt.detail.data; // data is located here
  const t = evt.detail.target; // chart mark/label clicked is located here

  this.currentClickedElement = [d]; // this is passed to clickHighlight prop
};

const hoverHandler = evt => {
  const d = evt.detail.data; // data is located here
  const t = evt.detail.target; // chart mark/label clicked is located here

  this.currentHoveredElement = d; // this is passed to hoverHighlight prop
};

const mouseOutHandler = evt => {
  this.currentHoveredElement = ''; // this is passed to hoverHighlight prop
};

// an example of calling these from within a stencil.js component
<heat-map
  data=[{data}]
  xAccessor="month"
  yAccessor="region"
  valueAccessor="value"
  interactionKeys={['region']}
  onClickEvent={this.onClickEvent}
  clickHighlight={this.currentClickedElement}
  clickStyle={this.clickStyle}
  onHoverEvent={this.onHoverEvent}
  onMouseOutEvent={this.onMouseOut}
  hoverHighlight={this.currentHoveredElement}
  hoverStyle={this.hoverStyle}
/>
//...

# Label Props <>

Name	Type	Default Value(s)	Description
`dataLabel`	object (custom type)	IDataLabelType	Controls visibility, styling and placement of data labels, see object definition below.
`legend`	object (custom type)	ILegendType	Controls visibility and label of the chart legend, see object definition below.
`showTooltip`	boolean	true	Toggles whether to display the tooltip on hover/focus on chart geometries.
`tooltipLabel`	object (custom type)	ITooltipLabelType	Controls visibility, content and format of the chart tooltip, see object definition below.

IDataLabelType Definition

Name	Type	Default Value(s)	Description
`labelAccessor`	string	''	Key used to determine label's property.
`visible`	boolean	true	Toggles the visibility (opacity) of the data labels.
`placement`	string	'top'	Sets the placement of the data label.
`format`	string	'0[.][0][0]a'	Sets the formatting for the data labels, EG %b, refer to d3-time-format and numeral.js.

ILegendType Definition

Name	Type	Default Value(s)	Description
`visible`	boolean	true	Toggles the visibility (opacity/display) of the legend.
`interactive`	boolean	false	Toggles the interactivity of the legend.
`format`	string	''	Sets the formatting for the legend labels, EG %b, refer to d3-time-format and numeral.js.
`labels`	string[]	''	An array that sets each label in the legend, in order. Passing empty string will populate legend labels directly from data values.
`type`	string	''	Sets the type of the legend, example types are 'default', 'gradient' and 'key'.

ITooltipLabelType Definition

Name	Type	Default Value(s)	Description
`labelAccessor`	string[]	[]	An array that determines which property of the data is displayed in the tooltip.
`labelTitle`	string[]	[]	An array that sets the title for each data property in the tooltip.
`format`	string	''	Sets the formatting for the data properties in the tooltip, EG %b, refer to d3-time-format and numeral.js.

# Margin & Padding Props <>

Name	Type	Default Value(s)	Description
`margin`	object (custom type)	IBoxModelType	Margin between the subtitle and the chart area, or between the title and chart area if no subtitle is specified, see object definition below.
`padding`	object (custom type)	IBoxModelType	Padding between plot area and axes lines, see object definition below.

IBoxModelType Definition

Name	Type	Default Value(s)	Description
`top`	number	height * 0.01	Sets the top margin/padding for the chart container.
`bottom`	number	height * 0.01	Sets the bottom margin/padding for the chart container.
`left`	number	width * 0.01	Sets the top margin/padding for the chart container.
`right`	number	width * 0.01	Sets the top margin/padding for the chart container.

# Style Props <>

Name	Type	Default Value(s)	Description
`colorPalette`	string	'single_blue'	Included color palettes can be found in our color utility. Overridden by colors.
`colorSteps`	number	5	Sets numbers of heatmap color steps.
`colors`	string[]	`undefined`	Accepts array of color strings or color values to customize colors beyond our palettes. Overridden by groupAccessor, colors assigned in order.
`roundedCorner`	number	0	Sets the border radius of the chart geometries.
`shape`	string	'rect'	Changes grid shape. (`rect` and `circle` are the only valid inputs)
`strokeWidth`	string	'2'	Changes stroke width of grids.

Usage no npm install needed!