| Available in: Logi Info | Source code name: RefreshSeriesTimer | Introduced in: 12.0.036 |
RefreshSeriesTimer updates charts automatically based on a time interval. When the interval is reached, a request is made back to the server to get updated data. Charts are updated with a smooth animation.
Charts may be refreshed in two ways. Either all the data is refreshed each time, or the chart data automatically slides to the left over time.
When the ChartXAxis element has AxisType="DateTimeLinear", newer values are added to the right side, previous values slide to the left, and old values fall out. Use the TimeSpan attribute to specify the age of data included.
When the TimeSpan attribute is set, the chart’s DataLayer may use a special @Chart token suitable for retrieving just the rows necessary to update the chart. On the initial chart request, @Chart.rdTimeSpanStart~ returns the current time minus the time span. But for subsequent refreshes, when AxisType="DateTimeLinear" and the x-axis will be sliding, @Chartt.rdTimeSpanStart~ returns the last time the chart was updated, so only the newest rows are retrieved. SQL Server example:
SELECT * FROM MyTable WHERE UpdateTime BETWEEN '@Chart.rdTimeSpanStart~' AND '@Function.DateTime~'.
The timer's interval is set in seconds. Be careful with setting a fast refresh rate if a very large number of users may display the report. |