Question

A simple app:

function doGet() {
  return(test());
}

function test(){
  var smiley = UiApp.createApplication().setTitle("TT Bomgar Feedback");
  var textIn = smiley.createTextBox().setName("text");
  var textOut = smiley.createLabel().setId("label").setVisible(false);
  var button = smiley.createSubmitButton("Submit");
  var handler = smiley.createServerHandler("handler");
  button.addClickHandler(handler);
  smiley.add(button);
  smiley.add(textIn);
  smiley.add(textOut);
  return(smiley);
}

function handler(e){
  app = UiApp.getActiveApplication();
  var text = e.parameter.text;
  app.getElementById("label").setVisible(true).setText(text);
  return(app);
}

In the handler function, var text is always undefined. This means that the following is returned:

So, undefined is printed instead of “some text”.

I don’t understand why though, because I have correctly set the name of the text box element in the test function …

Any assistance is greatly appreciated.

Answer 1

You need to add a callBackElemnt to the handler so that its value will get passed to the handler function. In normal practice, we just add the top most element containing all other elements. But you can also add all the elements whose value you want to pass.

modified script

var handler = smiley.createServerHandler("handler");
handler.addCallbackElement(textIn);
button.addClickHandler(handler);