We're constantly building customer solutions for Google Apps, Solve360, Freshbooks, and Xero with Google Apps Script and Google App Engine. Below is a handy tip for Google Apps Script developers.
Posted on behalf of Cameron Roberts, Senior Developer, Interlockit.com
When interacting with a Google Sites list page via the Google Apps Script SitesApp service, the documented getListItems() function returns only 200 items, while the maximum length of a List Page in sites is 500 Items. This function takes advantage of undocumented parameter values that can be passed to getListItems() to retrieve all items in batches of 200.
Function: getAllListPageItems(page)
Parameter: page - An instance of the Google Apps Script Services "ListPage" class.
Description: A robust function which uses undocumented Google Services functonality to retrieve ALL items from a list page. At time of writing (June 2012), the Google Services getListItems() method returns only the first 200 items of a ListPage. This function will catch failed API calls and re-try until all list items have been retrieved. This function will also throw an informative exception if the passed parameter is not a valid ListPage object.
Usage Example:
//retrieve items from list page and write to Log.
var page = SitesApp.getPageByUrl('http://
var items = getAllListItems(page);
for(var i in items){
var item = items[i];
Logger.log(item);
//..Perform your processing on list items here.
}
Written by Cameron Roberts, Interlockit.com
*/
function getAllListPageItems(page){
if(page && page.getPageType && page.getPageType() == 'ListPage'){
var items = [];
var start = 0;
var size = 200;
var failed = false;
do{
try{
var item_batch = page.getListItems({start:
failed = false;
items = items.concat(item_batch);
start += size;
}catch(e){
failed = true;
}
}while(item_batch.length == size || failed);
return items;
}else{
throw 'Parameter passed to getAllListItems was not a List Page: '+page;
}
}
The relevant post from Google, which exposes the undocumented functionality, is http://code.google.com/p/
