Firebase storage listAll() example.

code-snippet.js

// Load single image

// replace images/photo6244288433388366130.jpg with your image path
// You can find it on the firebase storage console
var imgRef = firebase.storage().ref().child('images/photo6244288433388366130.jpg'); 
imgRef.getDownloadURL().then(function(url){
    var img = document.getElementById('img1');
    img.src = url;

}).catch(function(error) {
  // A full list of error codes is available at
  // https://firebase.google.com/docs/storage/web/handle-errors
  switch (error.code) {
    case 'storage/object-not-found':
      // File doesn't exist
      console.log('file not exist');
      break;

    case 'storage/unauthorized':
      // User doesn't have permission to access the object
      console.log('permission problems');

      break;

    case 'storage/canceled':
      // User canceled the upload
      console.log('canceled');

      break;

    case 'storage/unknown':
      // Unknown error occurred, inspect the server response
      console.log('unknown');

      break;
  }
});




// Load all images within folder
// (and create img elements)

// First of all you need to edit your security rules from ver.1 to ver.2
rules_version = '2';   // Add this line
service firebase.storage { // Your rules here
  match /b/{bucket}/o {
    match /{allPaths=**} {
      allow read;
      allow write: if auth.uid == 'blablabla';
    }
  }
}

// On your Web Apps
// index.html
<div id="img-area"></div>

// script.js
var img_index = 1;
var storageRef = firebase.storage().ref();
var listRef = storageRef.child('images');
listRef.listAll().then(function(result){
    console.log(result);
    result.items.forEach(function(imgRef){
        imgRef.getDownloadURL().then(function(url){
            var img = $('<img />').attr({
                'id': 'poster'+img_index,
                'src': url,
                'alt': 'image',
                'title': 'image',
                'width': 250
            }).appendTo('#img-area');

            img_index++;
        });
    })
}).catch(function(error){
    console.log(error);
});