title: ionic 3 file uploading from filechooser to firebase storage
body: <p>I'm trying to upload a pdf from ionic 3 app to firebase.
  by using this method I can upload a text file by just creating them.` </p>
  
  <pre><code>uploadToStorage(information):AngularFireUploadTask
    {
      let newName = `${new Date().getTime()}.txt`;
      return this.afST.ref(`files/${newName}`).putString(information);
  
    }`
  </code></pre>
  
  <p>here is the place where i call the function</p>
  
  <pre><code>uploadInfo(text)
    {
      let upload = this.dataProvider.uploadToStorage(text);
  
      upload.then(res=&gt;{
        console.log('res',res);
        this.dataProvider.storeInfoOnDatabase(res.metadata,text).then(()=&gt;{
          let toast = this.toastCtrl.create({
            message : 'New File Added',
            duration: 3000
          });
          toast.present();
        });
      });
    }
  </code></pre>
  
  <p>what i need to do is how i expand the <code>uploadstorage()</code> function to upload a file getting from ionic file chooser</p>