What is the meaning of __paging_token query parameter which is returned in the Facebook paging urls?

Question

A typical facebook paging url looks like this:

https://graph.facebook.com/353409121371688/feed?access_token=<access_token>&since=1334318362&__paging_token=353409121371688_359606270751973&__previous=1&limit=25

Similarly, what is the meaning of the __previous query parameter?

Is there some place where all of these parameters have been documented?

Answer 1

When fetching the posts of a page, the response from facebook contains the paging links next and previous. Those will have a until or since parameter and additionally a parameter __paging_token

With only until the last post from the previous page is returned as first item of the next page.

Until seems to be the time of the last post on the previous page. And of course there might be more than one post at this time, so facebook returns all posts starting with this time. The paging token adds additional information for facebook so that the next page will start really at the next post.

Quoting: Spring Social Facebook - PagingParameters must use paging token

__previous not sure what its doing. When I checked its presence and absence was not doing anything.

Caution: Also I am not sure about for how long these __paging_token are valid.