public CallFunctionNode(VariableResolver functionName,
    VariableResolver continuationId) 
{
        this.functionName = functionName;
        this.continuationId = continuationId;
}

 public  void compose(ComponentManager manager) 
{
        this.manager = manager;
}

 public  void configure(Configuration config) throws ConfigurationException 
{
        //TODO (SW): Deprecate this in the future.
        // It has be found to be bad practice to pass sitemap parameters
        // as function arguments, as these are name-value pairs in the sitemap
        // and positional arguments in the flowscript. If the user doesn't respect
        // the argument order, this leads to difficult to solve bugs.
        parameters = new ArrayList();
        Configuration[] params = config.getChildren("parameter");
        for (int i = 0; i <  params.length; i++) {
            Configuration param = params[i];
            String name = param.getAttribute("name", null);
            String value = param.getAttribute("value", null);
            parameters.add(new Interpreter.Argument(name, value));
        }
}

Obtain the configuration specific to this node type and update the internal state.

 public boolean invoke(Environment env,
    InvokeContext context) throws Exception 
{
        List params = null;
        // Resolve parameters
        if (parameters != null) {
            params = resolveList(parameters, manager, context, env.getObjectModel());
        }
        // Need redirector in any case
        Redirector redirector = context.getRedirector();
        // If the continuation id is not null, it takes precedence over
        // the function call, so we invoke it here.
        String continuation = continuationId.resolve(context, env.getObjectModel());
        if (continuation != null && continuation.length()  > 0) {
            try {
                interpreter.handleContinuation(continuation, params, redirector);
            } catch(Exception e) {
                throw ProcessingException.throwLocated("Sitemap: error calling continuation", e, getLocation());
            }
            if (!redirector.hasRedirected()) {
                throw new ProcessingException("Sitemap: < map:call continuation > did not send a response", getLocation());
            }
            return true;
        }
        // We don't have a continuation id passed in < map:call >, so invoke
        // the specified function
        String name = functionName.resolve(context, env.getObjectModel());
        if (name != null && name.length()  > 0) {
            try {
                interpreter.callFunction(name, params, redirector);
            } catch(Exception e) {
                throw ProcessingException.throwLocated("Sitemap: error calling function '" + name + "'", e, getLocation());
            }
            if (!redirector.hasRedirected()) {
                throw new ProcessingException("Sitemap: < map:call function > did not send a response", getLocation());
            }
            return true;
        }
        // Found neither continuation nor function to call
        throw new ProcessingException("Sitemap: no function nor continuation given in < map:call function >", getLocation());
}

 public static List resolveList(List expressions,
    ComponentManager manager,
    InvokeContext context,
    Map objectModel) throws PatternException 
{
        int size;
        if (expressions == null || (size = expressions.size()) == 0)
            return Collections.EMPTY_LIST;
        List result = new ArrayList(size);
        for (int i = 0; i <  size; i++) {
            Interpreter.Argument arg = (Interpreter.Argument)expressions.get(i);
            String value = VariableResolverFactory.getResolver(arg.value, manager).resolve(context, objectModel);
            result.add(new Interpreter.Argument(arg.name, value));
        }
        return result;
}

 public  void setInterpreter(Interpreter interp) throws Exception 
{
        this.interpreter = interp;
}