Button firing only once Google Apps Script - google-apps-script

Question

I'm trying to get a button to fire more than once(I.e. multiple clicks) but it seems to not be working. Any help would be greatly appreciated. Theoretically it should fire multiple times but it only fires once when I check it in the logs
function a
{
...
var addcolumnspanel = app.createHorizontalPanel().setId("addcolumnspanel");
var addbuttonhandler = app.createServerHandler("addcolumn");
var addbutton = app.createButton().setId("btnaddcolumn").setText("Add another column").addClickHandler(addbuttonhandler);
...
return app;
}
function addcolumn()
{
...//Do some stuff
return app;
}
Here is a more precise code example
//set global var
var counter = 1;
var ss = SpreadsheetApp.getActiveSpreadsheet();
//Set up the Menu bar
function onOpen() {
// Logger.clear();
var menuEntries = [ {name: "demo", functionName: "myFunction"}];
ss.addMenu("Demo", menuEntries);
}
function myFunction() {
var myapp = UiApp.createApplication().setHeight(430).setWidth(800);;
var button = myapp.createButton("Clicky");
var myhandler = myapp.createServerHandler("secondfunction");
var myhandler = button.addClickHandler(myhandler)
myapp.add(button);
ss.show(myapp);
}
function secondfunction()
{
counter++;
Logger.log(counter);
}

Answer 1

OK. The problem is with the counter variable. You cannot use global variables that way in Apps Script. See this answer for more information. You can use ScriptProperties or CacheService as an alternative.
var ss = SpreadsheetApp.getActiveSpreadsheet();
//Set up the Menu bar
function onOpen() {
// Logger.clear();
var menuEntries = [ {name: "demo", functionName: "myFunction"}];
ss.addMenu("Demo", menuEntries);
// Store your counter in CacheService as a string.
CacheService.getPrivateCache().put('counter','1',3600);
}
function myFunction() {
var myapp = UiApp.createApplication().setHeight(430).setWidth(800);;
var button = myapp.createButton("Clicky");
var myhandler = myapp.createServerHandler("secondfunction");
var myhandler = button.addClickHandler(myhandler)
myapp.add(button);
ss.show(myapp);
}
function secondfunction()
{
var cache = CacheService.getPrivateCache();
var counter = parseInt(cache.get('counter'));
counter ++;
cache.put('counter', counter.toString());
Logger.log(counter);
}