SP REST: Assign user permissions #Javascript #SharePoint #REST

assign-SPREST-userPerms.js

function assignPerms(libraryName, folderName, usersPrincipalID, roleDefID)
{

	// To List the required Role Definition ID's : /_api/web/roleDefinitions()  ;
	// /_api/web/lists/getByTitle('Test')/roleassignments/addroleassignment(principalid=20,roleDefId=" + + ")"
var assignPerms = jQuery.ajax({
		url: _spPageContextInfo.webAbsoluteUrl + "/_api/web/GetFolderByServerRelativeUrl('" +  _spPageContextInfo.siteServerRelativeUrl + "/" + libraryName + "/" + folderName + "/ListItemAllFields/roleassignments/addroleassignment(principalid=" + usersPrincipalID + ",roleDefId=" + roleDefID + ")",
		type: 'POST',
		contentType: 'application/json;odata=verbose',
		headers: { 
		'Accept': 'application/json;odata=verbose',
		'content-type':'application/json;odata=verbose',
		'X-RequestDigest': $("#__REQUESTDIGEST").val()
		}
	});
	assignPerms.done(function(listData, textStatus, jqXHR)
	{
		console.dir(listData) ;
		console.dir(textStatus) ;
	});
}