Creating download prompt using purely javascript

Question

I have some text data (say var a = 'Hello World From Javascript';)in javascript variable in current window. I want to do the following through javascript-

1. open a new window and write the text data to the window.
2. set the content type to text/plain.
3. set the content-disposition to attachment, so that download prompt comes.
4. user downloads the text data as a text file and saves it to his local disk.

is this all possible through javascript?

I know we can make ajax calls to server or redirect but in this case instead of following above steps. But in this case, these workarounds are not adaptable.

Answer 1

you can do that using JS & HTML5 features. Please find below a sample code.

        var fileParts = ['Hello World From Javascript'];

        // Create a blob object.
        var bb = new Blob(fileParts,{type : 'text/plain'});

        // Create a blob url for this. 
        var dnlnk = window.URL.createObjectURL(bb);

        var currentLnk = $('#blobFl').attr('href');

        // blobFl is the id of the anchor tag through which the download will be triggered.

        $('#blobFl').attr('href',dnlnk);
        $('#blobFl').attr('download','helloworld.txt');

        // For some reason trigger from jquery dint work for me.
        document.getElementById('blobFl').click();