test_blob.htm

<a id="link" target="_blank" download="file.txt"> Click here to Download</a>

<script>

    var file;
    var data = [];
    data.push("This is a test\n");
    data.push("Of creating a file\n");
    data.push("In a browser\n");
    string = "";
    for (ii = 0; ii < 300000; ii++)
    {
        data.push("New line: " + ii + "aaa bbb ccc ddd eee fff ggg hhh iii jjj kkk lll mmm nnn\n");
        string += "New line: " + ii + "aaa bbb ccc ddd eee fff ggg hhh iii jjj kkk lll mmm nnn\n";
    }
    var properties = {type: 'text/plain'}; // Specify the file's mime-type.

    //data = string.split("\n"); // works ok
    data = [string];
    console.log("string DATA length: %s", data.length);

    try {
      // Specify the filename using the File constructor, but ...
      console.log("SAVE AS FILE");
      file = new File(data, "file.txt", properties);
    } catch (e) {
      // ... fall back to the Blob constructor if that isn't supported.
      console.log("SAVE AS BLOB");
      file = new Blob(data, properties);
    }
    console.log("After create FILE");
    var url = URL.createObjectURL(file);
    document.getElementById('link').href = url;
    console.log("After set link href");
    </script>