Google App Script - Spreadsheet JSON export

gistfile1.js

/**
 * Adds a custom menu to the active spreadsheet, containing a single menu item
 * for invoking the exportJSON() function specified above.
 * The onOpen() function, when defined, is automatically invoked whenever the
 * spreadsheet is opened.
 * For more information on using the Spreadsheet API, see
 * https://developers.google.com/apps-script/service_spreadsheet
 */
function onOpen() {
  var sheet = SpreadsheetApp.getActiveSpreadsheet();
  var entries = [{
    name : "Do it",
    functionName : "exportJSON"
  }];
  sheet.addMenu("Export JSON", entries);
};

// triggers parsing and displays results in a text area inside a custom modal window
function exportJSON() {
  var app = UiApp.createApplication().setTitle('JSON export results - select all and copy!');
  var textArea = app.createTextArea();
  textArea.setValue(makeJson(SpreadsheetApp.getActiveSheet().getDataRange()));
  app.add(textArea);
  textArea.setSize("100%", "100%");
  SpreadsheetApp.getActiveSpreadsheet().show(app);
};

function makeJson(dataRange) {
  var charSep = '"';
  
  var result = "", thisName = "", thisData = "";
  
  var frozenRows = SpreadsheetApp.getActiveSheet().getFrozenRows();
  var dataRangeArray = dataRange.getValues();
  var dataWidth = dataRange.getWidth();
  var dataHeight = dataRange.getHeight() - frozenRows;
  
  // range of names - we assume that the last frozen row is the list of properties
  var nameRangeArray = dataRangeArray[frozenRows - 1];
    
  // open JSON object - if there's a extra frozen row on the top wrap results into that as property (only supports one for now)
  result += frozenRows > 1 ? '{"' + dataRangeArray[frozenRows - 2][0] + '": [' : '[';
  
  for (var h = 0; h < dataHeight ; ++h) {
    
    result += '{';
    
    for (var i = 0; i < dataWidth; ++i) {
     
      thisName = nameRangeArray[i];
      thisData = dataRangeArray[h + frozenRows][i];

      // add name 
      result += charSep + thisName + charSep + ':'
        
      // add data
      result += charSep + jsonEscape(thisData) + charSep + ', ';
      
    }
    
    //remove last comma and space
    result = result.slice(0,-2);
    
    result += '},\n';
    
  }
  
  //remove last comma and line break
  result = result.slice(0,-2);

  // close object
  result += frozenRows > 1 ? ']}' : ']';
    
  return result;
    
}

function jsonEscape(str)  {
  if (typeof str === "string" && str !== "") {
    return str.replace(/\n/g, "<br/>").replace(/\r/g, "<br/>").replace(/\t/g, "\\t");
  } else {
    return str;
  }
}