add example and download buttons

index.html

@@ -19,7 +19,9 @@
           <textarea class="area" id="ta_turtle"></textarea>
         </div>
         <div class="form-group">
+          <input type="button" id="btn_example" class="btn btn-default" value="Load Example"/>
           <input type="button" id="btn_validate" class="btn btn-default" value="Validate!"/>
+          <input type="button" id="btn_download" class="btn btn-default" value="Download"/>
         </div>
       </form>
       <ul id="errors"></ul>

js/app.js

@@ -23,3 +23,39 @@ var editor = CodeMirror.fromTextArea(document.getElementById("ta_turtle"), {
     mode: 'turtle',
     theme: 'default'
 });
+
+var example =
+   ['@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .',
+    '@prefix dc: <http://purl.org/dc/elements/1.1/> .',
+    '@prefix ex: <http://example.org/stuff/1.0/> .',
+    '<http://www.w3.org/TR/rdf-syntax-grammar>',
+    '  dc:title "RDF/XML Syntax Specification (Revised)" ;',
+    '  ex:editor [',
+    '    ex:fullname "Dave Beckett";',
+    '    ex:homePage <http://purl.org/net/dajobe/>',
+    '  ] .'
+   ].join('\n');
+
+$("#btn_example").click( function () {
+editor.setValue(example);
+});
+
+$("#btn_download").click( function () {
+var textToWrite = editor.getValue();
+var textToWrite = textToWrite.replace(/\n/g, "\r\n");
+var textFileAsBlob = new Blob([textToWrite], {type:'text/plain'});
+var fileNameToSaveAs = "FILENAME.ttl";
+var downloadLink = document.createElement("a");
+downloadLink.download = fileNameToSaveAs;
+downloadLink.innerHTML = "Turtle Web Editor Content";
+window.URL = window.URL || window.webkitURL;
+downloadLink.href = window.URL.createObjectURL(textFileAsBlob);
+downloadLink.onclick = destroyClickedElement;
+downloadLink.style.display = "none";
+document.body.appendChild(downloadLink);
+downloadLink.click();
+});
+
+function destroyClickedElement(event) {
+document.body.removeChild(event.target);
+}