List files

List keys under a specified path, as well as lastModified timestamp.

Public level list

1Storage.list('photos/') // for listing ALL files without prefix, pass '' instead
2  .then(({ results }) => console.log(results))
3  .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

1{
2  results: [
3    {
4      eTag: ""30074401292215403a42b0739f3b5262"",
5      key: "123.png",
6      lastModified: "Thu Oct 08 2020 23:59:31 GMT+0800 (Singapore Standard Time)",
7      size: 138256
8    },
9    // ...
10  ],
11  hasNextToken: false
12}

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:

1function processStorageList(response) {
2  let files = [];
3  let folders = new Set();
4  response.results.forEach((res) => {
5    if (res.size) {
6      files.push(res);
7      // sometimes files declare a folder with a / within then
8      let possibleFolder = res.key.split('/').slice(0, -1).join('/');
9      if (possibleFolder) folders.add(possibleFolder);
10    } else {
11      folders.add(res.key);
12    }
13  });
14  return { files, folders };
15}

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:

1function processStorageList(response) {
2  const filesystem = {};
3  // https://stackoverflow.com/questions/44759750/how-can-i-create-a-nested-object-representation-of-a-folder-structure
4  const add = (source, target, item) => {
5    const elements = source.split('/');
6    const element = elements.shift();
7    if (!element) return; // blank
8    target[element] = target[element] || { __data: item }; // element;
9    if (elements.length) {
10      target[element] =
11        typeof target[element] === 'object' ? target[element] : {};
12      add(elements.join('/'), target[element], item);
13    }
14  };
15  response.results.forEach((item) => add(item.key, filesystem, item));
16  return filesystem;
17}

This places each item's data inside a special __data key.

Protected level list

To list current user's objects:

1Storage.list('photos/', { level: 'protected' })
2  .then(({ results }) => console.log(results))
3  .catch((err) => console.log(err));

To get other users' objects:

1Storage.list('photos/', {
2  level: 'protected',
3  identityId: 'xxxxxxx' // the identityId of that user
4})
5  .then(({ results }) => console.log(results))
6  .catch((err) => console.log(err));

Private level list

1Storage.list('photos/', { level: 'private' })
2  .then(({ results }) => console.log(results))
3  .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.

1Storage.list('photos/', { pageSize: 'ALL' })
2  .then(({ results }) => console.log(result))
3  .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:

1const PAGE_SIZE = 20;
2let nextToken = undefined;
3let hasNextPage = true;
4//...
5const loadNextPage = async () => {
6  if (hasNextPage) {
7    let response = await Storage.list('', {
8      pageSize: PAGE_SIZE,
9      nextToken: nextToken
10    });
11    if (response.hasNextToken) {
12      nextToken = response.nextToken;
13    } else {
14      nextToken = undefined;
15      hasNextPage = false;
16    }
17    // render list items from response.results
18  }
19};

Note: The range of pageSize can be from 0 - 1000 or 'ALL'.

Get file properties

Copy files