fiddle/res/imp/text-src.html

<!-- The <text-src> custom element declaration.

  Displays text loaded from a URL in the same way an image
  loads and displays from a URL.

  Attributes:
    src - The URL to read the text from.

  Events:
    None.

  Methods:
    None.
-->

<dom-module id="text-src">
  <template>
    <pre>[[ _text ]]</pre>
  </template>
</dom-module>

<script>
  Polymer({
    is: "text-src",

    properties: {
      src: {
        type: String,
        value: "",
        reflectToAttribute: true,
        observer: "srcChange",
      },
      _text: {
        type: String,
        value: "",
      }
    },

    srcChange: function() {
      if (this.src == "") {
        return
      }
      sk.get(this.src).then(function(text) {
        this._text = text;
      }.bind(this)).catch(function() {
        this._text = "";
      }.bind(this));
    },

  });
</script>