google_form_api

google_form_api.gs

function doGet(e) {
  var form = FormApp.openById(e.parameter.form_id);
  var items = form.getItems();

  var result = {form_id: form.getId(), items: []};
  for (var i = 0; i < items.length; i++) {
    var item = items[i];
    var itemId = item.getId();
    var itemTitle = item.getTitle();
    var itemType = String(item.getType());

    switch (itemType) {
      case 'TEXT':
        var item = item.asTextItem();
        break;
      case 'MULTIPLE_CHOICE':
        var item = item.asMultipleChoiceItem();
        break;
      case 'LIST':
        var item = item.asListItem();
        break;
      case 'CHECKBOX':
        var item = item.asCheckboxItem();
        break;
    }

    var itemChoices = [];
    if (itemType !== 'TEXT') {
      var choices = item.getChoices();
      for (var j = 0; j < choices.length; j++) {
        itemChoices[j] = {value: choices[j].getValue()};
      }
    }
    
    result.items[i] = {id: itemId, title: itemTitle, type: itemType, choices: itemChoices};
  }

  return ContentService.createTextOutput(JSON.stringify(result));
}

function doPost(e) {
  var responseObject = getResponseObject(e.parameters);
  var form = FormApp.openById(responseObject.formId);

  var itemResponses = [];
  for (var i = 0; i < responseObject.responseItems.length; i++) {
    var responseItemObject = responseObject.responseItems[i];
    var item = form.getItemById(responseItemObject.responseItemId);
    var itemType = String(item.getType());

    switch (itemType) {
      case 'TEXT':
        item = item.asTextItem();
        break;
      case 'MULTIPLE_CHOICE':
        item = item.asMultipleChoiceItem();
        break;
      case 'LIST':
        item = item.asListItem();
        break;
      case 'CHECKBOX':
        item = item.asCheckboxItem();
        break;
    }

    itemResponses.push(item.createResponse(responseItemObject.responseItemValues));
  }

  var formResponse = form.createResponse();
  for (var i = 0; i < itemResponses.length; i++) {
    formResponse = formResponse.withItemResponse(itemResponses[i]);
  }
  formResponse.submit();
}