C.4 Expand Tag Library

The Expand tag library contains functionalities specific to the Operations Center application for expanding a query against the performance engine.

To reference this custom tags in the Operations Center tag library, add the following code to the top of the JSP file before the <html> tag:

URL = <%@ taglib uri="http://www.managedobjects.com/taglibs/remote/query/expand" prefix="expand" %>

An expansion increases the amount of the data returned by the query by adding all data that matches the expansion criteria. For example, to produce a result set containing a cube of data for each hour of the day since yesterday, use the time expansion with an hour interval. The query result is 24 cubes of data.

As with the constrain tags, the expand tags must be used within the createQuery tag. All of the tags belonging to this tag library have no attributes, except for the time tag:

C.4.1 time

Expands the result cubes based on a time interval:

<% String end = "" + System.currentTimeMillis(); %>
    <expand:time from='<%=start%>' to='<%=end%>' interval=”months”/>

For example, to obtain a result set containing a cube for each day of the last month, use the time expansion with a day’s interval. This returns 30 cubes of data in the query result, if the month has 30 days. This tag has three attributes: from, to, and interval. The from and to attributes specify the start and end dates of a period as a long value. The mandatory interval attribute provides time intervals, such as: "seconds", "minutes", "hours", "days", "weeks", "months", "years", "milliseconds".