如何在Amserial图表中添加图例 [英] How to add legends in Amserial charts
问题描述
我在AngularJS应用程序中使用Amcharts创建一个简单的条形图.以下是我在控制器中的代码:
let empChart;
let empBarGraph;
let empLine;
const writeemp = data => {
const {
total,
employees,
} = data;
empChart.dataProvider = e;
empChart.write('emp');
empChart.validateData();
};
AmCharts.handleLoad();
var configChart = function () {
empChart = new AmCharts.AmSerialChart();
empChart.categoryField = "state";
empChart.labelRotation = 90;
var yAxis = new AmCharts.ValueAxis();
yAxis.position = "left";
empChart.addValueAxis(yAxis);
empBarGraph = new AmCharts.AmGraph();
empBarGraph.valueField = "count";
empBarGraph.type = "column";
empBarGraph.fillAlphas = 1;
empBarGraph.lineColor = "#f0ab00";
empBarGraph.valueAxis = yAxis;
empChart.addGraph(empBarGraph);
empChart.write('empChart');
$http.get(hostNameService.getHostName()+"/dashboard/employees/statecount")
.then(response => writeemp(response.data));
}
HTML代码:
<div class='panel-body'>
<div id="empChart"></div>
</div>
这将在x轴上返回State的值，并在y轴上返回State的值.我想根据状态值过滤图表，并且不确定如何为该图表创建图例.谁能建议我如何使用图例.我想为要返回的状态值创建图例.
您可以使用基于OO的语法添加图例，方法是通过new AmCharts.AmLegend()创建图例对象，然后通过调用图表的addLegend将其添加到类中.方法:
var legend = new AmCharts.AmLegend();
empChart.addLegend(legend);
如果希望图例在悬停在列上时显示值，则需要在图表中添加ChartCursor:
var cursor = new AmCharts.ChartCursor();
empChart.addChartCursor(cursor);
您可以通过设置valueText属性来更改图例在列翻转时显示的内容.它允许在balloonText和labelText之类的字段中使用相同的[shortcodes]，例如legend.valueText = "[[category]]: [[value]]".如果您需要像以前的问题一样动态自定义返回的文本，则还可以使用设置其valueFunction.图例对象中可用的所有属性都可以在 AmLegend API文档中找到./p>
已更新:
图例仅适用于图形对象，因此没有现成的方法可让您将每个列表示为图例项，该图例项可切换其他列的可见性，除非您愿意重新组织数据集并为每个状态使用不同的图形对象.一种解决方法是使用图例的自定义data数组并添加一些事件处理，以便单击自定义数据项可以通过在dataProvider中取消设置count valueField来添加/删除切换.
以下带注释的代码完成了您要执行的操作:
//create the legend but disable it until the dataProvider is populated,
//since you're retrieving your data using AJAX
var legend = new AmCharts.AmLegend();
legend.enabled = false;
chart.addLegend(legend);
chart.toggleLegend = false;
// Callback that handles clicks on the custom data entry markers and labels
var handleLegendClick = function(legendEvent) {
//Set a custom flag so that the dataUpdated event doesn't fire infinitely
legendEvent.chart.toggleLegend = true;
// The following toggles the markers on and off.
// The only way to "hide" a column is to unset the valueField at the data index,
// so a temporary "storedCount" property is added to the dataProvider that stores the
// original value so that the value can be restored when the legend marker is toggled
// back on
if (undefined !== legendEvent.dataItem.hidden && legendEvent.dataItem.hidden) {
legendEvent.dataItem.hidden = false;
legendEvent.chart.dataProvider[legendEvent.dataItem.stateIdx].count = legendEvent.chart.dataProvider[legendEvent.dataItem.stateIdx].storedCount; //restore the value
} else {
// toggle the marker off
legendEvent.dataItem.hidden = true;
legendEvent.chart.dataProvider[legendEvent.dataItem.stateIdx].storedCount = legendEvent.chart.dataProvider[legendEvent.dataItem.stateIdx].count; //store the value
legendEvent.chart.dataProvider[legendEvent.dataItem.stateIdx].count = undefined; //set to undefined to hide the column
}
legendEvent.chart.validateData(); //redraw the chart
}
chart.addListener('dataUpdated', function(e) {
var legendDataItems; //used to store the legend's custom data array.
if (e.chart.toggleLegend === true) {
//is the user toggling a legend marker? stop here as the dataProvider will get updated in handleLegendClick
e.chart.toggleLegend = false;
return;
}
// if we're at this point, the data provider was updated.
// reconstruct the data array.
// initialize by grabbing the state, setting a color and stoing the index
// for toggline the columns later
legendDataItems = e.chart.dataProvider.map(function(dataElement, idx) {
return {
'title': dataElement.state,
'color': graph.lineColor,
'stateIdx': idx //used in toggling
}
});
// if the legend is not enabled, then we're setting this up for the first time.
// turn it on and attach the event handlers
if (e.chart.legend.enabled === false) {
e.chart.legend.enabled = true;
e.chart.legend.switchable = true;
e.chart.legend.addListener('clickMarker', handleLegendClick);
e.chart.legend.addListener('clickLabel', handleLegendClick);
}
// update the legend custom data and redraw the chart
e.chart.legend.data = legendDataItems;
e.chart.validateNow();
});
以下是一个小提琴，它对此进行了说明: http://jsfiddle.net/g254sdq5/1/
I am using Amcharts in my AngularJS Application to create a simple bar chart.The following is my code in the controller:
let empChart;
let empBarGraph;
let empLine;
const writeemp = data => {
const {
total,
employees,
} = data;
empChart.dataProvider = e;
empChart.write('emp');
empChart.validateData();
};
AmCharts.handleLoad();
var configChart = function () {
empChart = new AmCharts.AmSerialChart();
empChart.categoryField = "state";
empChart.labelRotation = 90;
var yAxis = new AmCharts.ValueAxis();
yAxis.position = "left";
empChart.addValueAxis(yAxis);
empBarGraph = new AmCharts.AmGraph();
empBarGraph.valueField = "count";
empBarGraph.type = "column";
empBarGraph.fillAlphas = 1;
empBarGraph.lineColor = "#f0ab00";
empBarGraph.valueAxis = yAxis;
empChart.addGraph(empBarGraph);
empChart.write('empChart');
$http.get(hostNameService.getHostName()+"/dashboard/employees/statecount")
.then(response => writeemp(response.data));
}
Code in html:
<div class='panel-body'>
<div id="empChart"></div>
</div>
This would return me the values of State on x-axis and count on y-axis. I wanted to filter the chart based on the value of state and was not sure how to create the legends for this chart. could anyone suggest me on how to use legends. I want to create legends for the state value that is being returned.
You can add a legend using the OO-based syntax by creating a legend object through new AmCharts.AmLegend() and adding it to the class by calling the chart's addLegend method:
var legend = new AmCharts.AmLegend();
empChart.addLegend(legend);
If you want the legend to show values upon hovering over a column, you need to add a ChartCursor to your chart:
var cursor = new AmCharts.ChartCursor();
empChart.addChartCursor(cursor);
You can change what the legend displays upon column rollover by setting the valueText property. It allows for the same [shortcodes] used in fields like balloonText and labelText, e.g. legend.valueText = "[[category]]: [[value]]". You can also use set its valueFunction if you need to customize the text it returns dynamically like in your previous questions. All of the properties available in the legend object can be found in the AmLegend API documentation.
Updated:
Legends work off of graph objects only, so there isn't an out of the box method that allows you to represent each column as a legend item that toggles the other columns' visibility unless you're willing to reorganize your dataset and use different graph objects for each state. A workaround for this is to use the the legend's custom data array and add some event handling so that clicking on the custom data items adds/removes a toggle by unsetting your count valueField in the dataProvider.
The following annotated code accomplishes what you're trying to do:
//create the legend but disable it until the dataProvider is populated,
//since you're retrieving your data using AJAX
var legend = new AmCharts.AmLegend();
legend.enabled = false;
chart.addLegend(legend);
chart.toggleLegend = false;
// Callback that handles clicks on the custom data entry markers and labels
var handleLegendClick = function(legendEvent) {
//Set a custom flag so that the dataUpdated event doesn't fire infinitely
legendEvent.chart.toggleLegend = true;
// The following toggles the markers on and off.
// The only way to "hide" a column is to unset the valueField at the data index,
// so a temporary "storedCount" property is added to the dataProvider that stores the
// original value so that the value can be restored when the legend marker is toggled
// back on
if (undefined !== legendEvent.dataItem.hidden && legendEvent.dataItem.hidden) {
legendEvent.dataItem.hidden = false;
legendEvent.chart.dataProvider[legendEvent.dataItem.stateIdx].count = legendEvent.chart.dataProvider[legendEvent.dataItem.stateIdx].storedCount; //restore the value
} else {
// toggle the marker off
legendEvent.dataItem.hidden = true;
legendEvent.chart.dataProvider[legendEvent.dataItem.stateIdx].storedCount = legendEvent.chart.dataProvider[legendEvent.dataItem.stateIdx].count; //store the value
legendEvent.chart.dataProvider[legendEvent.dataItem.stateIdx].count = undefined; //set to undefined to hide the column
}
legendEvent.chart.validateData(); //redraw the chart
}
chart.addListener('dataUpdated', function(e) {
var legendDataItems; //used to store the legend's custom data array.
if (e.chart.toggleLegend === true) {
//is the user toggling a legend marker? stop here as the dataProvider will get updated in handleLegendClick
e.chart.toggleLegend = false;
return;
}
// if we're at this point, the data provider was updated.
// reconstruct the data array.
// initialize by grabbing the state, setting a color and stoing the index
// for toggline the columns later
legendDataItems = e.chart.dataProvider.map(function(dataElement, idx) {
return {
'title': dataElement.state,
'color': graph.lineColor,
'stateIdx': idx //used in toggling
}
});
// if the legend is not enabled, then we're setting this up for the first time.
// turn it on and attach the event handlers
if (e.chart.legend.enabled === false) {
e.chart.legend.enabled = true;
e.chart.legend.switchable = true;
e.chart.legend.addListener('clickMarker', handleLegendClick);
e.chart.legend.addListener('clickLabel', handleLegendClick);
}
// update the legend custom data and redraw the chart
e.chart.legend.data = legendDataItems;
e.chart.validateNow();
});
Here's a fiddle that illustrates this: http://jsfiddle.net/g254sdq5/1/
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