Alerters are the Best.
Reports without the use of alerters are like indecipherable and uninteresting colors and shapes on a canvas. Alerters paint your report with the details that give it meaning and depth. There is usually a lot to convey when viewing a block of data, so alerters are good for pointing the viewer's eye toward what you want them to see. In other programs like Excel, the function that Alerters in Business Objects serves is known as Conditional Formatting. More than that, though, alerters can also be used to conditionally return report objects and display variables as well. In Business Objects, a cell can also have multiple conditions within one alerter, giving multiple scenarios for the alerter to act upon.
Also, one cell can have multiple alerters active on it, so you can have an alerter that does nothing but turns a Null into a regular 0 and another one that changes the font to red if it's over or under a certain value. It is good to separate these into two separate alerters so that you can reuse the Null to Zero alerter on multiple columns, and the Greater Than X alerter on the column that applies to.
Figure 1 is an example of using two alerters on one cell in our custom Quarterly Performance Report, which is based on our Performance Management Plan that outlines goals for our CoC projects. This particular example is of the Exits to Permanent Housing goal.
Figure 1: One cell with two alerters
You'll notice in the image above that I have expanded the "Alerters" section of the Properties tab in the left sidebar of the ART reporting window. You can see that there are two alerters with checkmarks since I have highlighted the "% of Exits" cell over in the report. (See the red circle.) Each alerter has a different purpose. The "Destination" alerter basically tells the cell when to use a red font. See Figure 2.
Our Performance Management Plan says that the Emergency Shelter goal is 30% and the other program types have a goal of 83%. You can see this in the logic above. Neither condition was met, so the font shown in Figure 1 is black.
The other alerter (Figure 3) deals with null values. It is also using multiple conditions and I only include it because its purpose is kind of interesting.
Basically the problem before adding this alerter was that when an agency had no Leavers whose Destination could be examined, the viewer was seeing a red "0%" as if they missed the goal, which is really the wrong message. Similarly, if they did have leavers, but no permanent destinations, it was not returning any value at all. So this alerter looks at the "LeaverCount" variable, and if it finds no leavers, it returns "N/A" in a simple black font since, if an agency didn't have any leavers, they neither met nor missed the goal. Similarly, if the LeaverCount shows that there were leavers, but none exited to permanent destinations, it returns a "0%" in a red font since they did miss the goal here.
If you need assistance learning how to build an alerter, you should go into ART, click the question mark in the top right corner, and search on Alerters.
Some interesting things I learned about Alerters in the Help documentation:
- Business Objects only officially supports up to 30 alerters in one report. (Our QPR has 31!)
- You can have up to 10 alerters on one cell or column or row!
- One alerter can contain up to 6 conditions.
And something important that is mentioned but not really explained in the Help documentation is that the order of the alerters does make a difference, so you want to be sure that the conditions the first alerter implements are not accidentally overwritten by the condition(s) in the second alerter. It is easy to adjust the order of the alerters, you just have to be aware that they trigger in a certain order and that can sometimes cause unexpected things to happen.
Alerters are a versatile and very powerful way report designers can draw out the significance of data for viewers, giving otherwise dull or confusing reports greater and clearer meaning. Use them well!