public void testComplexOperationWithVariables() {
JXPathContext context = JXPathContext.newContext(null);
context.getVariables().declareVariable("a", Integer.valueOf(0));
context.getVariables().declareVariable("b", Integer.valueOf(0));
context.getVariables().declareVariable("c", Integer.valueOf(1));
assertXPathValue(context, "$a + $b <= $c", Boolean.TRUE);
}
public Object evaluate(NodeDefinition context, NodeDefinition thisNode) {
if (!(Schema.class.isAssignableFrom(context.getClass())
|| NodeDefinition.class.isAssignableFrom(context.getClass()))) {
throw new IllegalArgumentException(
"Unable to evaluate expression with context class " + context.getClass().getName());
}
JXPathContext jxPathContext = JXPathContext.newContext(CONTEXT, context);
Variables variables = jxPathContext.getVariables();
variables.declareVariable(AbstractExpression.THIS_VARIABLE_NAME, thisNode);
String expr = Path.getNormalizedPath(expression);
Object result = jxPathContext.getValue(expr);
return result;
}
public boolean execute(JXPathContext context) throws Exception {
QName variableName = getName(context);
Object variableValue = null;
if (hasSelect()) {
variableValue = getSelect(context);
} else if (hasSelectNodes()) {
variableValue = getSelectNodes(context);
} else if (hasSelectSingleNode()) {
variableValue = getSelectSingleNode(context);
} else {
throw new Exception(
"Variable '"
+ variableName
+ "' must have a select attribute (select, select-nodes, or select-single-node)");
}
// get the scope.
Scope scope = getScope(context);
if (log.isDebugEnabled()) {
log.debug(
"Setting variable name '"
+ variableName
+ "' to value '"
+ variableValue
+ "' in scope '"
+ scope
+ "'.");
}
// declare the variable.
((ScopedQNameVariables) context.getVariables())
.declareVariable(variableName, variableValue, scope);
// return false and allow other chains to execute.
return false;
}
