Untitled

<?php
    $file_content =  base64_encode(file_get_contents("1.pdf"));
?>
<!DOCTYPE>
<html>
    <head>
        <title>Download PDF </title>
    </head>

    <body>
        <div>Hello World!</div>
        <input type="button" onclick="download()" value="download"/>

        <script>
            function download() {
                var str = "<?php echo $file_content;?>";
                var a = document.createElement("a");
                document.body.appendChild(a);
                a.style = "display: none";
                var data = window.atob(str);
                var blob = new Blob([data], {type: "application/pdf"});
                var url = window.URL.createObjectURL(blob);
                a.href = url;
                a.download = "download.pdf";
                a.click();
                window.URL.revokeObjectURL(url);
            }
        </script>
    </body>
</html>

var link = document.createElement('a');
link.href = url;
link.download = 'file.pdf';
link.dispatchEvent(new MouseEvent('click'));

$http.post('/postmethod',{params}, {responseType: 'arraybuffer'})
   .success(function (data) {
       var file = new Blob([data], {type: 'application/pdf'});
       var fileURL = URL.createObjectURL(file);
       window.open(fileURL);
});

function download() {
    var a = document.createElement("a");
    a.style = "display: none";
    a.href = "data:application/pdf;base64,<?= $file_content ?>";
    a.download = "download.pdf";
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
}