Truthfully, it's a bit light but https://ibm-maximo-dev.github.io/maximo-autoscript-documentation/bestpractice/overview is where we intend to cover this. 

I want to enhance this when I have time and create a series of blogs to go a bit deeper. For example, choosing the right launch point is critical but we only talk about a few examples of it here and there are a lot of examples of code that works but isn't optimized because the developer chose the wrong event.

I'd also inform developers to avoid count() entirely over just minimizing it. There are very few circumstances where you need to know the actual count but don't need to process the data. Typically, I see developers using this to loop through records or determine if records exist. Both can be achieved without using count() which will always cause another database query. For example, if you want to determine if a record exists use set.notExist() instead. This will check the in-memory set first to see if we have any Mbos. If the set hasn't been initialized it will execute a query against dummy_table with an exist() statement instead. This allows the database to stop processing once 1 record is returned whereas the count requires every record to be returned from the query first. If you're trying to loop through records, start at 0 and iterate until your Mbo is null. 

if service.isLoggingEnabled():
  service.log("count of mbos "+mboset.count())​

from psdi.common.context import UIContext
if UIContext.getCurrentContext() is not None and UIContext.isFromListTab()==False:
    ..costly initlization..​

if service.webclientsession() and service.webclientsession().getCurrentApp().onListTab():
    ... costly initialization...​

Are there differences? What is the better way?

Belonging to that, is there any way to stop processing if we are in a resultset in startcenter? I neither get a UIContext nor a WebClientSession.

I want to clarify that while I wrote some of the documentation on this wiki, by far the large majority of this documentation was written by Anamitra in his personal time including this page. The goal of the wiki was to make it easier to maintain with multiple contributors to ensure that we keep it current as we release new capabilities in the framework. 

With that out of the way, the isLoggingEnabled() is not in the latest MAS release either. I'm not sure if that was something planned that ended up getting dropped from the release for some reason. What I would do instead is getting the logger like:
logger=service.getLogger("maximo.script."+scriptName)

Then from there you can call the various methods such as:
if logger.isDebugEnabled():

I personally prefer using the logger directly over utilizing the service variable logging functions. 


On the UIContext, good catch. I'll submit a PR to update the example.

We use the UIContext for service.webclientsession() so there's no difference between:
UIContext.getCurrentContext().getWebClientSession()
and
service.webclientsession()

There is technically a difference between UIContext.getCurrentContext().isFromListTab() and service.webclientsession().getCurrentApp().onListTab(). The UIContext stores some data such as the app name and whether it's on the list tab and we retrieve from that. When you call service.webclientsession().getCurrentApp() you're retrieving an AppInstance object which is part of our UI framework that you're interacting with. I'd expect the outcome to be identical and inconsequential from a performance perspective so either approach should be fine.

Regarding start centers, I haven't tried to do anything here. I try to avoid initialize on the object entirely (only on the attributes). This way the logic is only invoked when the attribute is requested. I don't think we set anything special like we do when we're going through a table download but this would be good to investigate. 

if service.isLoggingEnabled():  service.log("count of mbos "+mboset.count())​

from psdi.common.context import UIContextif UIContext.getCurrentContext() is not None and UIContext.isFromListTab()==False:    ..costly initlization..​

if service.webclientsession() and service.webclientsession().getCurrentApp().onListTab():    ... costly initialization...​