Cannot upload images to Firebase Storage

Question

First I initialized a Polymer app-drawer-template using the Polymer cli and then I added Firebase storage to the web app. Then I added file upload code to one of the pages (The code for the page is found below). However I am getting the following errors (This prevents files from being uploaded and also does not update the progress bar),

Uncaught TypeError: Cannot read property 'addEventListener' of null

and also

Uncaught TypeError: Cannot read property 'instanceCount' of undefined

This is my code.

<link rel="import" href="../bower_components/polymer/polymer.html">

<dom-module id="my-market">

  <template>

    <style>
      :host {
        display: block;
        padding: 10px;
      }
      paper-card.top{
        margin-top: 8px;
        width: 100%;
        padding-bottom: 16px;
      }
    </style>

    <paper-card heading="Welcome to the Market!">
      <div class="card-content">
        <h4>Upload a photo of your item</h4>
        <!--uplod image-->
        <input type="file" value="upload" id="fileUpload"/>
        <progress value="0" max="100" id="uploader">0%</progress>
      </div>
    </paper-card>

  </template>

  <script>

   //File upload script to Firebase storage
  var uploader = document.getElementById('uploader');
  var fileButton = document.getElementById('fileUpload');

  //File selection listener
  fileButton.addEventListener('change', function(a) {

    //Get image
    var file = a.target.files[0];

    //create a storage reference
    var storageRef = firebase.storage().ref('images/' + file.name);

    //store the image
    var task = storageRef.put(file);

    //notify the user of upload status
    task.on('state_changed',

        function progress(snapshot) {
          var percentage = (snapshot.bytesTransferred/snapshot.totalBytes)*100;
          uploader.value = percentage;
        },

        function error(err) {

        },

        function complete() {

        }

    );

  });

  </script>


  <script>

    Polymer({

      is: 'my-market'

    });

  </script>

</dom-module>

I also tried to place the code for Firebase Storage in the tag of the index.html file but it's still not working. Any suggestions?

Answer 1

This is the fix.

Just put your script inside the Polymer({}); function.

Polymer({

  is: 'my-market',

  upld: function(a) {
      //Get image
     var file = a.target.files[0];

     //create a storage reference
     var storageRef = firebase.storage().ref('images/' + file.name);

     //store the image
     var task = storageRef.put(file);

 }

});

And specify the on-change attribute to "upld" for the file input.