Get ID of a Parent Folder in a Document Library

Question

For the following folder structure, let's say I am viewing documents under "Level 2 Folder", I would like to get ID for "Level 2 Folder" using JavaScript, either using JSCOM or Rest API for SharePoint Online.

-Level 1 Folder
--Level 2 Folder
---Level 3 Document

Answer 1

Try the below REST API endpoint to get the Folder Item ID,

_spPageContextInfo.webAbsoluteUrl + "/_api/web/GetFolderByServerRelativeUrl('" + ctx.rootFolder + "')/listitemallfields/id"

Example:

http://sharepointsite/_api/web/GetFolderByServerRelativeUrl('/Library/Level 1 Folder/Level 2 Folder')/listitemallfields/id

Answer 2

Use the below url for REST call

var restUrl = _spPageContextInfo.webAbsoluteUrl + "/_api/web/GetFolderByServerRelativeUrl('" + ctx.rootFolder + "'/UniqueId"

Answer 3

This turned out to be very simple.

ctx.ListData.FolderId