List files
List keys under a specified path, as well as lastModified
timestamp.
Public level list
Storage.list('photos/') // for listing ALL files without prefix, pass '' instead .then(({ results }) => console.log(results)) .catch((err) => console.log(err));
Note the trailing slash /
- if you had requested Storage.list('photos')
it would also match against files like photos123.jpg
alongside photos/123.jpg
.
The format of the response will look similar to the below example
{ results: [ { eTag: ""30074401292215403a42b0739f3b5262"", key: "123.png", lastModified: "Thu Oct 08 2020 23:59:31 GMT+0800 (Singapore Standard Time)", size: 138256 }, // ... ], hasNextToken: false}
Manually created folders will show up as files with a size
of 0, but you can also match keys against a regex like file.key.match(/\.[0-9a-z]+$/i)
to distinguish files vs folders. Since "folders" are a virtual concept in S3, any file may declare any depth of folder just by having a /
in its name. If you need to list all the folders, you'll have to parse them accordingly to get an authoritative list of files and folders:
function processStorageList(response) { let files = []; let folders = new Set(); response.results.forEach((res) => { if (res.size) { files.push(res); // sometimes files declare a folder with a / within then let possibleFolder = res.key.split('/').slice(0, -1).join('/'); if (possibleFolder) folders.add(possibleFolder); } else { folders.add(res.key); } }); return { files, folders };}
If you need the files and folders in terms of a nested object instead (for example, to build an explorer UI), you could parse it recursively:
function processStorageList(response) { const filesystem = {}; // https://stackoverflow.com/questions/44759750/how-can-i-create-a-nested-object-representation-of-a-folder-structure const add = (source, target, item) => { const elements = source.split('/'); const element = elements.shift(); if (!element) return; // blank target[element] = target[element] || { __data: item }; // element; if (elements.length) { target[element] = typeof target[element] === 'object' ? target[element] : {}; add(elements.join('/'), target[element], item); } }; response.results.forEach((item) => add(item.key, filesystem, item)); return filesystem;}
This places each item's data inside a special __data
key.
Protected level list
To list current user's objects:
Storage.list('photos/', { level: 'protected' }) .then(({ results }) => console.log(results)) .catch((err) => console.log(err));
To get other users' objects:
Storage.list('photos/', { level: 'protected', identityId: 'xxxxxxx' // the identityId of that user}) .then(({ results }) => console.log(results)) .catch((err) => console.log(err));
Private level list
Storage.list('photos/', { level: 'private' }) .then(({ results }) => console.log(results)) .catch((err) => console.log(err));
Access all files
To get a list of all files in your S3 bucket under a specific prefix, you can set pageSize to ALL. The default value of pageSize is 1000.
Storage.list('photos/', { pageSize: 'ALL' }) .then(({ results }) => console.log(result)) .catch((err) => console.log(err));
Paginated file access
If the pageSize is set lower than the total file size, a single Storage.list
call only returns a subset of all the files. To list all the files with multiple calls, users can use the hasNextToken
and nextToken
keys:
const PAGE_SIZE = 20;let nextToken = undefined;let hasNextPage = true;//...const loadNextPage = async () => { if (hasNextPage) { let response = await Storage.list('', { pageSize: PAGE_SIZE, nextToken: nextToken }); if (response.hasNextToken) { nextToken = response.nextToken; } else { nextToken = undefined; hasNextPage = false; } // render list items from response.results }};