Google Apps Script: Display single column based on

I am trying to develop a gradebook with Google Spreadhseets, but I only want to display individual grades based on user email. Is there a Google Apps Script function that looks at a logged in user's email, searches the spreadhseet for it (it would be at the top of a column) and then displays that column back to the user?

I think the best solution would probably be to create a small webapp Ui that shows only the relevant column in a html table. Depending on your programming skills it can be quite easy to setup. I could have suggested an example but you gave too few information about the type of data that are in the spreadsheet... User's data are in a single column but I suppose there is also some kind of headers or row identifiers that must be shown to understand what is shown ?

Users will have to authorize the webapp in order to let you identify them when they are logged in.

Edit : here is a simple example of a possible solution that you can start from.

I assumed mails are in row 1, descriptions in column A.

var ss = SpreadsheetApp.openByUrl('https://docs.google.com/spreadsheet/ccc?key=0AnqSFd3iikE3dGdQOXZpRmJnT0xjQklkdEZING5YREE#gid=0');
var sh1 = ss.getSheetByName('sheet1');
var logsheet = ss.getSheetByName('logsheet');
var data = sh1.getDataRange().getValues();
var user = Session.getEffectiveUser()


function doGet() {
       var app = UiApp.createApplication();
       if(!getcol(user)){
          var warn = app.createTextBox().setWidth('500').setValue("Your results are not available or you don't have permission to view these data");// if user is not in the list, warning + return
app.add(warn)
return app
          }
       var grid = app.createGrid(data.length, 2).setBorderWidth(1).setCellPadding(2);
       var text = app.createTextBox().setName('text').setId('text').setValue(user+'  | idx'+getcol(user) ).setWidth('300px');
       var btn = app.createButton('press here to confirm you have view these results');
       var handler = app.createServerHandler('log').addCallbackElement(grid);
       btn.addClickHandler(handler);
       var col = getcol(user)
       grid.setWidget(0,1,text).setText(0, 0, 'Results for');
       grid.setStyleAttribute('textAlign','center')
       for(n=1;n<data.length;++n){
         grid.setText(n, 0, data[n][0])
         grid.setText(n, 1, data[n][col])
         }
       app.add(grid).add(btn)
       return app
    }

function log(e){
      var text = e.parameter.text
      var app = UiApp.getActiveApplication();
    // add user name to the log sheet + timestamp + eventually send a mail etc...
    return app
    }


function getcol(mail){
  if(data[0].toString().indexOf(mail.toString())!=-1){
  for(zz=1;zz<data[0].length;++zz){
    if(data[0][zz] == mail){var colindex=zz;break}
  }
   return colindex
  }
  return false
}

EDIT2 : To print numbers with the desired number of decimals you can use the recently implemented printf function like this :

grid.setText(n, 1, Utilities.formatString('%.2f',data[n][col]));// 2 decimals, no leading 0

to show dates like you want use formatDate()

Utilities.formatDate(date, Session.getTimeZone(), "MM-dd")

EDIT3 :

here is a version that handles the different types of data :

var ss = SpreadsheetApp.openByUrl('https://docs.google.com/spreadsheet/ccc?key=0AnqSFd3iikE3dGdQOXZpRmJnT0xjQklkdEZING5YREE#gid=0');
var sh1 = ss.getSheetByName('sheet1');
var logsheet = ss.getSheetByName('logsheet');
var data = sh1.getDataRange().getValues();
var user = Session.getEffectiveUser()
Logger.log(user)


function doGet() {
       var app = UiApp.createApplication();
       if(!getcol(user)){
          var warn = app.createTextBox().setWidth('500').setValue("Your results are not available or you don't have permission to view these data");// if user is not in the list, warning + return
app.add(warn)
return app
          }
       var grid = app.createGrid(data.length, 2).setBorderWidth(1).setCellPadding(2).setStyleAttribute('background','#ffeeaa').setId('grid');
       var text = app.createTextBox().setName('text').setId('text').setValue(user+'  | idx'+getcol(user) ).setWidth('300px');
       var btn = app.createButton('press here to confirm you have view these results');
       var handler = app.createServerHandler('log').addCallbackElement(grid);
       btn.addClickHandler(handler);
       var col = getcol(user)
       grid.setWidget(0,1,text).setText(0, 0, 'Results for');
       grid.setStyleAttribute('textAlign','center')
       for(n=1;n<data.length;++n){
         grid.setText(n, 0, string(data[n][0]));
         grid.setText(n, 1, string(data[n][col]));
         }
       grid.setStyleAttributes(n-1, 0, {'fontWeight':'bold','background':'#ffff99'})
       grid.setStyleAttributes(n-1, 1, {'fontWeight':'bold','background':'#ffff99'})
       app.add(grid).add(btn)
       return app
    }

function log(e){
      var text = e.parameter.text
      var app = UiApp.getActiveApplication();
      app.getElementById('grid').setStyleAttribute('background','#bbffbb')
    // add user name to the log sheet + timestamp + eventually send a mail etc...
    return app
    }


function string(value){
Logger.log(typeof(value))
if (typeof(value)=='string'){return value};// if string then don't do anything
if (typeof(value)=='number'){return Utilities.formatString('%.1f / 20',value)};// if number ther format with 1 decimal
if (typeof(value)=='object'){return Utilities.formatDate(value, Session.getTimeZone(), "MM-dd")};//object >> date in this case, format month/day
return 'error'
}


function getcol(mail){
  if(data[0].toString().indexOf(mail.toString())!=-1){
  for(zz=1;zz<data[0].length;++zz){
    if(data[0][zz] == mail){var colindex=zz;break}
  }
   return colindex
  }
  return false
}