Evaluator

This package contains an evaluator that has an xpath-like syntax.

Context

Take these classes as example:

class MyObject {
	String myField, myVar;
	List<MyObject> myList;
}

Suppose you perform this query:

myObject/myList[myField = myVar]

This will return all instances of MyObject in the variable myList where the string myField matches the value of the string myVar. Both myField and myVar will be located in the context of the MyObject instances that are in the list.

However if the value of either variable is "null" in the list context for a specific instance, there are two booleans that will trigger other behavior:

• allowParentLookup (default false): this will search all parents (going up the stack) to find the variable. Use with caution, naming collisions are likely in moderately complex scenarios
• allowRootLookup (default false): this will search for the variable at the root level, this should drastically reduce the chance for naming collisions

In the default scenario you can still access all parent contexts by using subsequent ".." to browse upwards:

myObject/myList[myField = ../myVar]

Alternatively you can directly address the root context by using an absolute path:

myObject/myList[myField = /myVar]