Refreshing Charts to Reflect Real Time Data
The polling interval property is an optional property for all charts. It specifies the time in milliseconds for the chart’s data to refresh. You can use this for charts that receive any kind of real time data, such as a JSON file that changes periodically. This ensures that the chart is up to date, reflecting the most recent data. Follow these steps to configure your chart to use real time data.
Add a new java scriptlet and create a new instance of the chart’s object, and put the data into the
dataattribute. Finally, set the chart’s polling interval with the
setPollingInterval()method. An example
view.jspconfiguration is shown below:
```java <% LineChartConfig _pollingIntervalLineChartConfig = new LineChartConfig(); _pollingIntervalLineChartConfig.put("data", "/foo.json"); _pollingIntervalLineChartConfig.setPollingInterval(2000); %> ```
Set the chart taglib’s
configattribute to the updated configuration object that you created in the last step, as shown in the example below:
```jsp <chart:line componentId="polling-interval-line-chart" config="<%= _pollingIntervalLineChartConfig %>" /> ```
Now you know how to reflect real time data in your charts!