How to access source widget's value in GAS? - google-apps-script

Question

I'm trying to write a generic server handler for textboxes which highlights the text when the textbox gains focus:
function onFocusHighlight(e) {
var app = UiApp.getActiveApplication();
var widget = app.getElementById(e.parameter.source);
var widgetValue = e.parameter.widgetName; // how can I get widgetName from source???
widget.setSelectionRange(0, widgetValue.length);
return app;
}
Can I determine widgetValue from e.parameter.source?

Answer 1

var widget = app.getElementById(e.parameter.source).setName("widgetName")
Then get widgetValue:
var widgetValue = e.parameter.widgetName
Check https://developers.google.com/apps-script/uiapp for usage of setName.

Answer 2

I've found that as long as widgetName and widgetId are the same I can determine widgetValue as follows:
function onFocusHighlight(e) {
var app = UiApp.getActiveApplication();
var widgetId = e.parameter.source;
var widgetName = widgetId; // name MUST match id to retrieve widget value
var widgetValue = e.parameter[widgetName]; // not sure why this syntax works???
var widget = app.getElementById(widgetId);
widget.setSelectionRange(0,widgetValue.length);
return app;
}
My only issue now is understanding how/why the e.parameter[widgetName] syntax actually works. It would also be great to have a solution which doesn't rely on widgetName and widgetId being the same value.

Answer 3

Just a suggestion following your own answer :
You could probably make it work by having a conversion table somewhere that gets the widgets name from their ID.
For example you could define :
ScriptProperties.setProperties({'widgetID1':'Name1','widgetID2':'name2'},true)
and then
widgetvalue = e.parameter[ScriptProperties.getProperty(e.parameter.source)]
I didn't test this code but it seems logical ;-), tell me if it doesn't (I don't have time to test it now)
EDIT : works as expected, here is a test sheet to show the result, test code below.
function Test(){
var app = UiApp.createApplication().setTitle('test');
app.add(app.createLabel('Type anything in upper textBox and then move your mouse over it...'))
var p = app.createVerticalPanel()
var txt1 = app.createTextBox().setId('txt1').setName('Name1').setValue('value in TextBox1')
var txt2 = app.createTextBox().setId('txt2').setName('Name2').setValue('waiting to mouseOver textBox1')
p.add(txt1).add(txt2)
app.add(p)
var handler = app.createServerHandler('mouseOver').addCallbackElement(p);
txt1.addMouseOverHandler(handler);
ScriptProperties.setProperties({'txt1':'Name1','txt2':'Name2'},true);//save the name, only txt1 will be used here
var ss=SpreadsheetApp.getActiveSpreadsheet()
ss.show(app)
}
function mouseOver(e) {
var app = UiApp.getActiveApplication();
var widget = app.getElementById(e.parameter.source);
var widgetValue = e.parameter[ScriptProperties.getProperty(e.parameter.source)]; // ScriptProperties knows the Widget's name
app.getElementById('txt2').setValue(widgetValue) ;// Use the other widget to show result
return app;
}