From a salesforce site, we want to retrieve the page count of pdf documents stored in a SharePoint site, How to get this through REST or some alternative way?
If I understand correctly you want to get the number of pages of pdf documents. For example, aaa.pdf has 5 pages, bbb.pdf has 3 pages, ...
OOTB this is not possible. The pdf metadata like number of pages is not captured by SharePoint. Using Search rest api also does not offer a solution.
There are apps that can extract this kind of information during uploading and then store the values into SharePoint columns. These columns can then be queried using REST.
An alternative is to develop logic that downloads the pdf files and then parses the pdf file to extract the number of pages.
Paul | SLIM Applications