Tag name: <dvt:alert>

Use the alert tag for a graph to define an additional data point that needs to be highlighted with a separate symbol, such as an error or warning). An icon marks the location of the alert. When the mouse hovers over the alert icon, the text of that alert is displayed. In the case of a continuous time access graph, the alert does not have to reference an existing data point.

Relationship with other tags

The alert tag is a child of the alertSet tag.


The following example shows the XML for two alert tags that are wrapped in an alertSet tag.

         <dvt:alert xValue="Boston" yValue="3.50" yValueAssignment="Y1AXIS" imageSource="myWarning.gif"/>
         <dvt:alert xValue="Boston" yValue="5.50" yValueAssignment="Y1AXIS" imageSource="myError.gif"/>


Name Type Supports EL? Description
id java.lang.String no Specifies the identifier for the component
xValue java.lang.String yes Indicates the x-axis or ordinal axis value for the alert. For example, in a bar graph, you might specify a group such as "Boston" or "Chicago" if points on the axis represent cities. In a scatter graph, this value is a number. The value for this attribute can be String, Double, or Date.
yValue double yes Indicates the y-axis value for the alert. The value must be a Double.
yValueAssignment java.lang.String yes Identifies which axis the yValue attribute is associated with. Valid values are:
  • Y1AXIS - (Default) yValue is associated with the y1-axis.
  • Y2AXIS - yValue is associated with the y2-axis.
imageSource java.lang.String yes Specifies the URL for the icon image that will be displayed for the alert.
text java.lang.String yes Specifies text that appears in a tooltip when a mouse pointer hovers over the icon.
rendered boolean yes Specifies whether the alert is visible in the graph. Valid values are "true" (Default) and "false".