google app script print button

    function printPdf() {
    SpreadsheetApp.flush();
    var ss = SpreadsheetApp.getActiveSpreadsheet();
    var sheet = ss.getActiveSheet();

    var gid = sheet.getSheetId();

    var pdfOpts = '&size=A4&fzr=false&portrait=false&fitw=true&gridlines=false&printtitle=false&shee        tnames=false&pagenum=UNDEFINED&attachment=false&gid='+gid;


    var row2 = 29;
    var printRange = '&c1=0' + '&r1=0' + '&c2=7' + '&r2='+row2; // B2:APn
    var url = ss.getUrl().replace(/edit$/, '') + 'export?format=pdf' + pdfOpts + printRange;

    var app = UiApp.createApplication().setWidth(200).setHeight(50);
    app.setTitle('Print this sheet');

    var link = app.createAnchor('Download PDF', url).setTarget('_new');

    app.add(link);

    ss.show(app);
     }

This is a code that worked for me. It's modified from another thread.

I guess you know that Google Apps Script applications have no way to print anything from inside your application since it runs on Google servers and not on you computer. Spreadsheets and documents integrate a print utility in their own environment but webapps (and sites) you develop with GAS don't have this environment.

Your 'print button' could probably create a pdf document that you'll be able to print easily.