How to get all Groovy variables with the last values using reflection - reflection

Question

I would like in my groovy script to dump all variables and display all values.
I would like to do it dynamically because I would like to surround all my huge groovies by a try/catch. In catch part I want to dump all variables state with the stacktrace. The code should be generic to all groovies.
The problem is that this.getBinding().getVariables() doesn't return the correct variable state.
I've made a small script to illustrate the situation:
def test1 = 1;
test1 = 2;
int test2 = 1;
test2 = 2;
test3 = 1;
test3 = 2;
def errLog=new File("c:/temp/groovy_debug.txt");
errLog.append("--------------------------------------------------------" + "\n");
errLog.append(" Context ["+getBinding().getVariables()+" ] \n");
errLog.append("--------" + "\n") ;
after the execution I get a very strange result
--------------------------------------------------------
Context [[[creationStackTrace= <not available>], test1:null, errLog:null, test2:null, test3:2] ]
--------
it means that the declared variables are always reported as null or as first assignment, but for not typed variables it get the last value.
I would like to get the last situation for all variables (value=2).
Is it possible to get them?

Answer 1

Tim Yates' answer illustrates why you're having difficulty accessing the non-global variables. For simple cases like yours, where you just have assignments and declarations, you can use a visitor to collect the results, like this
import org.codehaus.groovy.ast.expr.*
import org.codehaus.groovy.ast.stmt.*
import org.codehaus.groovy.ast.*
import org.codehaus.groovy.control.*
import org.codehaus.groovy.classgen.*
import java.security.CodeSource
def scriptText = '''
def test1 = 1;
test1 = 2;
int test2 = 1;
test2 = 2;
test3 = 1;
test3 = 2;
'''
class VariableVisitor extends ClassCodeVisitorSupport {
def vars = [:]
void visitExpressionStatement(ExpressionStatement statement) {
if (statement.expression instanceof BinaryExpression)
vars.put(statement.expression.leftExpression.name, statement.expression.rightExpression.value)
super.visitExpressionStatement(statement)
}
void visitReturnStatement(ReturnStatement statement) {
if (statement.expression instanceof BinaryExpression)
vars.put(statement.expression.leftExpression.name, statement.expression.rightExpression.value)
super.visitReturnStatement(statement)
}
protected SourceUnit getSourceUnit() {
return source;
}
}
class CustomSourceOperation extends CompilationUnit.PrimaryClassNodeOperation {
CodeVisitorSupport visitor
void call(SourceUnit source, GeneratorContext context, ClassNode classNode) throws CompilationFailedException {
classNode.visitContents(visitor)
}
}
class MyClassLoader extends GroovyClassLoader {
CodeVisitorSupport visitor
protected CompilationUnit createCompilationUnit(CompilerConfiguration config, CodeSource source) {
CompilationUnit cu = super.createCompilationUnit(config, source)
cu.addPhaseOperation(new CustomSourceOperation(visitor: visitor), Phases.CLASS_GENERATION)
return cu
}
}
def visitor = new VariableVisitor()
def myCL = new MyClassLoader(visitor: visitor)
def script = myCL.parseClass(scriptText)
assert visitor.vars == ["test1":2, "test2":2, "test3":2]
However, if your script has more complicated stuff going on (like conditional assignments), you'll need something more sophisticated. You'd need to actually run the script and collect the results.