harmony 鸿蒙chart

2023-06-24
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chart

The <chart> component displays line charts and bar charts.

NOTE

This component is supported since API version 4. Updates will be marked with a superscript to indicate their earliest API version.

Child Components

Not supported

Attributes

Name	Type	Mandatory	Description
type	string	No	Chart type. Dynamic modification is not supported. Available values include: - bar: bar chart - line: line chart Default value: line
options	ChartOptions	Yes	Chart parameters. You can set the minimum value, maximum value, scale, and line width of the x-axis or y-axis, whether to display the x-axis and y-axis, and whether the line is smooth. Dynamic modification is not supported.
datasets	Array<ChartDataset>	Yes	Data sets. You can set multiple datasets and their background colors.
id	string	No	Unique ID of the component.
style	string	No	Style declaration of the component.
class	string	No	Style class of the component, which is used to refer to a style table.
ref	string	No	Reference information of child elements, which is registered with the parent component on $refs.

Table 1 ChartOptions

Name	Type	Mandatory	Description
xAxis	ChartAxis	Yes	X-axis parameters. You can set the minimum value, maximum value, and scale of the x-axis, and whether to display the x-axis.
yAxis	ChartAxis	Yes	Y-axis parameters. You can set the minimum value, maximum value, and scale of the y-axis, and whether to display the y-axis.
series	ChartSeries	No	Data series parameters which cover the following: - Line style, such as the line width and whether the line is smooth. - Style and size of the white point at the start of the line. NOTE Only line charts support this attribute.

Table 2 ChartDataset

Name	Type	Default Value	Mandatory	Description
backgroundColor(deprecated)	<color>	#ff6384	No	Color of a line or bar. This attribute is not recommended.
strokeColor	<color>	#ff6384	No	Line color. Only line charts support this attribute.
fillColor	<color>	#ff6384	No	Fill color. For line charts, the value indicates the gradient color to fill.
data	Array<number>	-	Yes	Data of the drawn line or bar.
gradient	boolean	false	No	Whether to display the gradient color. Only line charts support this attribute.

Table 3 ChartAxis

Name	Type	Default Value	Mandatory	Description
min	number	0	No	Minimum value of the axis. Negative numbers are not supported. Only line charts support this attribute.
max	number	100	No	Maximum value of the axis. Negative numbers are not supported. Only line charts support this attribute.
axisTick	number	10	No	Number of scales displayed on the axis. NOTE The value ranges from 1 to 20. The display effect depends on the calculation result of Number of pixels occupied by the image width/(max-min). Lite wearables support integer calculation, and an error may occur in the case of inexhaustible division. Specifically, a segment of space may be left at the end of the x-axis. In the bar chart, the number of bars in each group of data is the same as the number of scales, and the bars are displayed at the scales.
display	boolean	false	No	Whether to display the axis.
color	<color>	#c0c0c0	No	Axis color.

Table 4 ChartSeries

Name	Type	Mandatory	Description
lineStyle	ChartLineStyle	No	Line style, such as the line width and whether the line is smooth.
headPoint	PointStyle	No	Style and size of the white point at the start of the line.
topPoint	PointStyle	No	Style and size of the top point.
bottomPoint	PointStyle	No	Style and size of the bottom point.
loop	ChartLoop	No	Whether to start drawing again when the screen is looped.

Table 5 ChartLineStyle

Name	Type	Default Value	Mandatory	Description
width	<length>	1px	No	Line width.
smooth	boolean	false	No	Whether the line is smooth.

Table 6 PointStyle

Name	Type	Default Value	Mandatory	Description
shape	string	circle	No	Shape of the highlight point. Available values are as follows: - circle
size	<length>	5px	No	Size of the highlight point.
strokeWidth	<length>	1px	No	Stroke width.
strokeColor	<color>	#ff0000	No	Stroke color.
fillColor	<color>	#ff0000	No	Fill color.
display	boolean	true	No	Whether to display the highlight spot.

Table 7 ChartLoop

Name	Type	Default Value	Mandatory	Description
margin	<length>	1	No	Number of erased points (horizontal distance between the latest drawn point and the earliest point). You are not advised to use margin together with topPoint, bottomPoint, or headPoint for mini-, small- and standard-system devices. If you do so, there is a possibility that the point is in the erase area and invisible.

Methods

Methods	Parameter	Description
append	{ serial: number, // Set the data subscript of the line chart to be updated. data: Array<number>, // Set the new data. }	Dynamically add data to an existing data series. The target series is specified based on serial, which is the subscript of the datasets array and starts from 0. datasets[index].data is not updated. Only line charts support this attribute. The value is incremented by 1 based on the horizontal coordinate and is related to the xAxis min/max setting.

Events

Name	Parameter	Description
click	-	Triggered when the component is clicked.
longpress	-	Triggered when the component is long pressed.
swipe⁵⁺	SwipeEvent	Triggered when a user quickly swipes on the component.

Styles

Name	Type	Default Value	Mandatory	Description
width	<length> \|<percentage>⁵⁺	-	No	Component width. If this attribute is not set, the default value 0 is used.
height	<length> \|<percentage>⁵⁺	-	No	Component height. If this attribute is not set, the default value 0 is used.
padding	<length>	0	No	Shorthand attribute to set the padding for all sides. The attribute can have one to four values: - If you set only one value, it specifies the padding for all the four sides. - If you set two values, the first value specifies the top and bottom padding, and the second value specifies the left and right padding. - If you set three values, the first value specifies the top padding, the second value specifies the left and right padding, and the third value specifies the bottom padding. - If you set four values, they respectively specify the padding for top, right, bottom, and left sides (in clockwise order).
padding-[left\|top\|right\|bottom]	<length>	0	No	Left, top, right, and bottom padding.
margin	<length> \|<percentage>⁵⁺	0	No	Shorthand attribute to set the margin for all sides. The attribute can have one to four values: - If you set only one value, it specifies the margin for all the four sides. - If you set two values, the first value specifies the top and bottom margins, and the second value specifies the left and right margins. - If you set three values, the first value specifies the top margin, the second value specifies the left and right margins, and the third value specifies the bottom margin. - If you set four values, they respectively specify the margin for top, right, bottom, and left sides (in clockwise order).
margin-[left\|top\|right\|bottom]	<length> \|<percentage>⁵⁺	0	No	Left, top, right, and bottom margins.
border-width	<length>	0	No	Shorthand attribute to set the margin for all sides.
border-color	<color>	black	No	Shorthand attribute to set the color for all borders.
border-radius	<length>	-	No	Radius of round-corner borders.
background-color	<color>	-	No	Background color.
display	string	flex	No	How and whether to display the box containing an element. Available values are as follows: - flex: flexible layout - none: not rendered
[left\|top]	<length> \|<percentage>⁶⁺	-	No	Edge of the element. - left: left edge position of the element. This attribute defines the offset between the left edge of the margin area of a positioned element and left edge of its containing block. - top: top edge position of the element. This attribute defines the offset between the top edge of a positioned element and that of a block included in the element.

Example

Line chart

   <!-- xxx.hml -->
   <div class="container">
     <chart class="chart" type="line" ref="linechart" options="{{lineOps}}" datasets="{{lineData}}"></chart>
     <input class="button" type="button" value="Add data" onclick="addData"/>
   </div>

   /* xxx.css */
   .container {
     flex-direction: column;
     justify-content: center;
     align-items: center;
     width: 454px;
     height: 454px;
     background-color: white;
   }
   .chart {
     width: 300px;
     height: 300px;
   }
   .button {
     width: 280px;
     border-radius: 0px;
   }

   // xxx.js
   export default {
     data: {
       lineData: [
         {
           strokeColor: '#0081ff',
           fillColor: '#cce5ff',
           data: [763, 550, 551, 554, 731, 654, 525, 696, 595, 628, 791, 505, 613, 575, 475, 553, 491, 680, 657, 716],
           gradient: false,
         }
       ],
       lineOps: {
         xAxis: {
           min: 0,
           max: 20,
           display: false,
         },
         yAxis: {
           min: 0,
           max: 1000,
           display: false,
         },
         series: {
           lineStyle: {
             width: "5px",
             smooth: true,
           },
           headPoint: {
             shape: "circle",
             size: 10,
             strokeWidth: 5,
             fillColor: '#ffffff',
             strokeColor: '#007aff',
             display: true,
           },
           loop: {
             margin: 2,
             gradient: true,
           }
         }
       },
     },
     addData() {
       this.$refs.linechart.append({
         serial: 0,
         data: [Math.floor(Math.random() * 400) + 400]
       })
     }
   }

lite_line

Bar chart

   <!-- xxx.hml -->
   <div class="container">
     <chart class="chart" type="bar" id="bar-chart" options="{{barOps}}" datasets="{{barData}}"></chart>
   </div>

   /* xxx.css */
   .container {
     flex-direction: column;
     justify-content: center;
     align-items: center;
     width: 454px;
     height: 454px;
     background-color: white;
   }
   .chart {
     width: 300px;
     height: 300px;
   }

   // xxx.js
   export default {
     data: {
       barData: [
         {
           fillColor: '#f07826',
           data: [763, 550, 551, 554, 731, 654, 525, 696, 595, 628],
         },
         {
           fillColor: '#cce5ff',
           data: [535, 776, 615, 444, 694, 785, 677, 609, 562, 410],
         },
         {
           fillColor: '#ff88bb',
           data: [673, 500, 574, 483, 702, 583, 437, 506, 693, 657],
         },
       ],
       barOps: {
         xAxis: {
           min: 0,
           max: 20,
           display: false,
           axisTick: 10
         },
         yAxis: {
           min: 0,
           max: 1000,
           display: false,
         },
       },
     }
   }

lite_bar