How to find out permissions for each tree element(folder or file) for another user using sharepoint api?

Question

I want to get answer for question:

Does userA can read the folder/tree ?

Application uses another user to communicate with sharpoint via sharepoint API.

I've googled the following request:

http://aissp2013/sites/Team/_api/web/lists/getbytitle('L2')/EffectiveBasePermissions

But it doesn't resolve my problem because it responds with permissions for current user!

1. Is there way to get permissions for another user for concrete element(folder or file or library)
2. Is there way to get permissions for another user for all elements and sub-elements ?

Answer 1

To get permissions per user SP.ListItem.getUserEffectivePermissions method is intended:

for SP.Folder

Url /_api/web/getFolderByServerRelativeUrl('<folder-rel-url>')/ListItemAllFields/getusereffectivepermissions(@u)?@u='<account>'
Method: Get

for SP.File

Url /_api/web/getFileByServerRelativeUrl('<file-rel-url>')/ListItemAllFields/getusereffectivepermissions(@u)?@u='<account>'
Method: Get

Note: account parameter needs to be provided in claims format

Regarding the question:

Does userA can read the folder/tree ?

the following example demonstrates how to retrieve permissions for a folder

 const accountName = "i:0#.f|membership|<name>@<tenant>.onmicrosoft.com"; 

  let endpointUrl = _spPageContextInfo.webAbsoluteUrl + "/_api/web/getFolderByServerRelativeUrl('/Shared Documents/Achive')/ListItemAllFields/getusereffectivepermissions(@u)?@u='" + encodeURIComponent(accountName) + "'";
  const content = await executeJson(endpointUrl);

  let roles = parseBasePermissions(content.d.GetUserEffectivePermissions);
  if(roles.viewListItems)
     console.log(`${accountName} has been granted permissions.`);

where

function parseBasePermissions(value)
{      
    let permissions = new SP.BasePermissions();
    permissions.initPropertiesFromJson(value);
    let result = {};
    for(var levelName in SP.PermissionKind.prototype) {
        if (SP.PermissionKind.hasOwnProperty(levelName)) {
            var permLevel = SP.PermissionKind.parse(levelName);
            if(permissions.has(permLevel))
                result[levelName] = true;
            else
                result[levelName] = false;
        }     
    }
    return result; 
}

is used to parse permission mask into roles

and

async function executeJson(url,options) {
    options = options || {};
    options.method = options.method || 'GET';
    options.headers = options.headers || {};
    options.headers["Accept"] = "application/json;odata=verbose";
    options.headers["Content-Type"] = "application/json;odata=verbose";
    if(options.method == "POST") {
        options.headers["X-RequestDigest"] = document.getElementById("__REQUESTDIGEST").value;
    }    
    if (options.body) {
       options.body = JSON.stringify(options.body);
    }  
    const rawResponse = await fetch(url,options);
    const content = await rawResponse.json();
    return content;
}

to perform REST request