fetchDelta() call is similar to that of fetchDeltaSince, except that you need not specify a time stamp as a parameter. Subscribe tracks your calls to this method, and returns the Transaction objects whose status has changed since your last call. If you have never called this method, Subscribe returns all Transaction created since January 1, 1970 (“epoch”).
For paging, specify the page size only for this method. Like fetchDeltaSince, there is no need to increment through page numbers, because this call keeps a record of the last item returned to you in the previous call. Each time you make this call, the results will continue from the last position in the result set.
Input
srd: sparse response description, a SOAP string (which must be a JSON object), in which you specify the elements you want returned.This parameter enables the calling system to constrain amethod call to return only components you specify. This gives you greater control over returned content, and improves response time within the Vindicia platform by reducing the processing needed for the call.
Some fields are required, either practically or in the WSDL, and will be returned regardless of the srd. A null srd returns the complete response.
pageSize: the number of records to display per page per call. This value must be greater than 0.
Output
return: an object of typeReturn that indicates the success or failure of the call.
transactions: an array of one or more Transaction objects whose status has changed since this method was last called.
startDate: the starting time stamp for the range of Transaction objects fetched.
endDate: the ending time stamp for the range of Transaction objects fetched.

