setName vs setId in Google App Script - google-apps-script

Question

In 'google script', on trigger of an event (button click), I am trying to change the name as well as Id of a textbox. Following is simplified code:
function addRow(e){
var app = UiApp.getActiveApplication();
app.getElementById('tbox')
.setId('txt1')
.setName('txt1');
}
Now, setId is working but setName is throwing me an error. Is there something that I am obviously missing?

Answer 1

From a quick test I did it seems that, although it does not throw an error if used alone, it is not possible to change an element's id, as shown in this little test:
function doGet() {
var app = UiApp.createApplication().setTitle('Button Test');
return app.add(app.createTextBox().setId('tbox').setName('tbox').setText('tbox')
.addKeyPressHandler(app.createServerHandler('inspectBox'))).add(
app.createButton('Change').addClickHandler(app.createServerHandler('btnClick')));
}
function inspectBox(e) {
var p = e.parameter;
var app = UiApp.getActiveApplication();
return app.add(app.createLabel('id: '+p.source)).add(
app.createLabel('name: '+(p.tbox ? 'tbox' : p.txt1 ? 'txt1' : 'not found')));
}
function btnClick() {
var app = UiApp.getActiveApplication();
app.getElementById('tbox').setId('txt1');
//app.getElementById('tbox').setName('txt1');
return app;
}
Later, if you comment the setId line and uncomment the setName one, then type a char in the textbox, you'll see that the name changes. And the setName call works fine if you continue working on the element using, for example, setText. Which is not true for setId, that fails if you try anything on the element.
Anyway, as commented by others, it's indeed odd that you have such a requirement. I guess you should find another way (possibly a better one) to do what you want (which you have not described).