In case you are using the <evaulate> tag within a <transition> tag and the method you evaluate returns a boolean of false the transition will not occur. This is just a special feature of the evalaute tag in case you use it in the mentioned context (within a transition tag).
how do I handle booleans if I have a result?
In general the evaluate tag allows you to execute a method on a bean and gives you the possibility to save the result via result="" attribute, e.g.:
So the result of the method bar will be saved under the name resultVarName.
<evaluate expression="foo.bar()" result="flowScope.resultVarName">
Does this answer you questions?
Have you taken a look at the sample projects?
I think the term should is not appropriate. The SpringTeam could mention that you should read the reference documentation, that you should study the sample applications, that you should browse the forum that......
I also think that the reference should give more details... not just a brief description and a sample.
They should explain all attributes and what type of value they expect... and give a description of each attribute too.
Imho we get here some really cool stuff for free and my way to appreciate that is to read this forum regulary and try to answer some questions (I'm also "new" to SWF).