DataItem

Type class

DataItem represents single element in data, for example a data point in a Serial Chart Series, e.g. a column.

DataItem defines relationship between structured data, required for specific chart type or task, and raw source data.

It also implements required calculations, updates related visual elements, etc.

@todo Description

Sources

DataItem can be used (imported) via one of the following packages.

// DataItem is available in all of the following modules.
// You only need to import one of them.

/**
 * --------------------------------------------------------
 * Import from: "core.ts"
 * Use like: am4core.DataItem
 * --------------------------------------------------------
 */
import * as am4core from "@amcharts/amcharts4/core";

// DataItem is available in all of the following modules.
// You only need to import one of them.

/**
 * --------------------------------------------------------
 * Include via: <script src="core.js"></script>
 * Access items like: am4core.DataItem
 * --------------------------------------------------------
 */

Inheritance

DataItem extends BaseObjectEvents.

DataItem is extended by LegendDataItem, ChartDataItem, SeriesDataItem, AxisDataItem, NavigationBarDataItem.

Properties

adapter
#

Type Adapter < DataItem, IDataItemAdapters >

Default new Adapter<DataItem,
IDataItemAdapters>(this)

Holds Adapter.

animations
#

Type Array < Animation >

A list of Animations objects currently mutating Data Item's values.

categories
#

Type object

An object containing categories.

clonedFrom
#

Type $type.Optional < this >

Inherited from BaseObject

Reference to the original object this object was cloned from. We need to keep this so we can disassociate it from source object when this object is disposed.

config
#

Type object

Inherited from BaseObject

Use this property to set JSON-based config. When set, triggers processing routine, which will go through all properties, and try to apply values, create instances, etc.

Use this with caution, as it is a time-consuming process. It's used for initialchart setup only, not routine operations.

dataContext
#

Type Object

Sets to a reference to an original object from Component's data.

A reference to an original object in Component's data, that this Data Item is derived from.

dates
#

Type object

An object containing dates.

depth
#

Type number

Depth of the Data Item.

In nested data structures, like TreeMap, this indicates the level this data point is at, in relation to the parent Data Item.

events
#

Type EventDispatcher < AMEvent < this, IDataItemEvents > >

Default new EventDispatcher()

Inherited from BaseObjectEvents

An EventDispatcher instance

hasProperties
#

Type boolean

Default false

Indicates whether Data Item has any properties set.

If it does not have any, the code can use this property to check whether they need to apply costly operation of re-applying properties, whenever Data Item-related element is redrawn, e.g. series.

hidden
#

Type boolean

Sets hidden flag for data item. Mostly used to initially hide data item.

Returns true if this Data Item is currently hidden.

id
#

Type $type.Optional < string >

Inherited from BaseObject

Sets the user-defined id of the element.

ignoreMinMax
#

Type boolean

Sets whether this data point should not be included in the scale and minimum/maximum calculations.

Exclude from min/max calculations?

E.g. some we may want to exclude a particular data point from influencing ValueAxis scale.

index
#

Type number

Data Item's position index in Component's data.

isHiding
#

Type boolean

Default false

Indicates whether Data Item is currently animiting from visible to hidden state.

isTemplate
#

Type boolean

Default false

Identifies if this object is a "template" and should not be treated as real object that is drawn or actually used in the chart.

locations
#

Type object

An object containing locations for the Data Item.

A location is a position within date or category, or, in some other cases, where there is no single point but rather some period.

opacity
#

Type number

Sets opacity for all Data Item's related elements (Sprites).

parent
#

Type $type.Optional < this >

When we are using a nested data structure, like for example in a TreeMap, this property points to a parent Data Item of this one.

properties
#

Type object

An object containing Data Item specific appearance properties in key-value pairs.

Sometimes a single Data Item needs to apply different properties than the rest of the data Series it is part of. E.g. a single column, represented by a Data Item needs to be filled with a different color than the reset of the ColumnSeries it belongs to.

That's where Data Item's properties come into play.

Please note that you should set Data Item-specific properties using setProperty() method, rather than access properties object directly.

sprites
#

Type Sprite[]

Default []

A list of Sprite elements that are associated with this Data Item.

E.g. an Axis Data Item has several separate elements associated with it, like AxisTick, AxisLabel, and Grid.

Data Item keeps track of all of them, so it can toggle all related visual elements when it itself is toggled.

uid
#

Type string

Inherited from BaseObject

Returns object's internal unique ID.

values
#

Type object

An object containing calculated values.

visible
#

Type boolean

Sets visibility of the Data Item.

Returns true if this Data Item is currently visible.

workingLocations
#

Type object

Current working locations.

There are 5 inherited items currently hidden from this list.

Methods

constructor()

#

Returns DataItem

Constructor

@todo Adding events to disposers produces errors in some cases, which means that chart is using disposed Data Items which is not right

animate(

animationOptions: IAnimationOptions[] | IAnimationOptions,
duration: number,
easing?: ( value: number) => number

)

#

Returns Animation

Creates and starts an Animation to interpolate (morph) Data Item's properties and/or values.

@see Animation

clone(

cloneId?: string

)

#

Returns this

Clones the Data Item, including all related data.

copyFrom(

source: this

)

#

Returns void

Copies all properties and related data from different data item.

dispatch(

eventType: Key,
data?: any

)

#

Returns void

Inherited from BaseObjectEvents

Dispatches an event using own event dispatcher. Will automatically populate event data object with event type and target (this element).

It also checks if there are any handlers registered for this sepecific event.

dispatchImmediately(

eventType: Key,
data?: any

)

#

Returns void

Inherited from BaseObjectEvents

Works like dispatch, except event is triggered immediately, without waiting for the next frame cycle.

dispose()

#

Returns void

Destroys this object and all related data.

getCurrentThemes()

#

Returns ITheme[]

Inherited from BaseObject

Returns a list of themes that should be applied to this element. It could either be a list of themes set explicitly on this element, or system-wide.

getDate(

name: string

)

#

Returns Date

Returns a Date value of the data field.

getDuration(

duration?: number

)

#

Returns $type.Optional < number >

Returns a duration (ms) the Data Item should take to animate from one value to another.

If the duration is not specified via parameter, this method will try to request a default duration from the related Component.

getValue(

name: string,
calculated?: CalculatedValue

)

#

Returns $type.Optional < number >

Returns a numeric value for specific data field.

If calculated is not set, it will return a raw value, as it is in source data.

If calculated is set, it will return a pre-calculated specific value.

getWorkingValue(

name: string

)

#

Returns $type.Optional < number >

Returns a current working value for a specific data field.

The actual value may differ from the one returned by getValue(). The latter returns static values from the data source.

getWorkingValue() returns current value, which is usually different if Data Item is animating from one state to another.

hide(

duration?: number,
delay?: number,
toValue?: number,
fields?: string[]

)

#

Returns $type.Optional < Animation >

Hides the Data Item and related visual elements.

isDisposed()

#

Returns boolean

Inherited from BaseObject

Returns if this object has been already been disposed.

setCalculatedValue(

name: string,
value: number,
calculated: CalculatedValue

)

#

Returns void

setCategory(

name: string,
value: string

)

#

Returns void

Sets a related category for this Data Item.

@todo Review description

setDate(

name: string,
date: Date,
duration?: number

)

#

Returns void

Sets Date value to a data field.

setLocation(

name: string,
value: number,
duration?: number,
delay?: number

)

#

Returns void

Sets a relative location for a data field.

A location is always relative on a 0 to 1 scale, with 0 being beginning, 0.5 middle and 1 end.

@todo Rewiew description

setProperty(

name: string,
value: any

)

#

Returns void

Sets a Data Item-specific visual properties to apply to related elements.

setValue(

name: string,
value: number,
duration?: number,
delay?: number

)

#

Returns void

Sets a numeric value for specific data field.

setVisibility(

value: boolean,
noChangeValues?: boolean

)

#

Returns void

Sets visibility of the Data Item.

setWorkingLocation(

name: string,
value: number,
duration?: number,
delay?: number

)

#

Returns $type.Optional < Animation >

Sets a current working location for a data field.

@todo Rewiew description

setWorkingValue(

name: string,
value: number,
duration?: number,
delay?: number

)

#

Returns $type.Optional < Animation >

Set current working numeric value for a specific data field.

show(

duration?: number,
delay?: number,
fields?: string[]

)

#

Returns $type.Optional < Animation >

Shows the Data Item and related visual elements.

There are 4 inherited items currently hidden from this list.

Events

#calculatedvaluechanged

Param { type: "calculatedvaluechanged",
  target: this }

Invoked when the calculated value has changed

#locationchanged

Param { type: "locationchanged",
  target: this }

Invoked when the location of Data Item changes

#propertychanged

Param { type: "propertychanged",
  target: this }

Invoked when a property of the Data Item changes

#valuechanged

Param { type: "valuechanged",
  target: this }

Invoked when the value is changed

#visibilitychanged

Param { type: "visibilitychanged",
  target: this }

Invoked when the visibility of the Data Item changes, i.e. Series is hidden

#workinglocationchanged

Param { type: "workinglocationchanged",
  target: this }

Invoked when working location of Data Item changes

#workingvaluechanged

Param { type: "workingvaluechanged",
  target: this }

Invoked when the internal/intermediate value has changed

Adapters

#date

Param object

#duration

Param number

#value

Param object

#workingValue

Param object