javascript - Feed FileReader from server side files -

i´m starting customize/improve old audio editor project. can import audio tracks canvas via drag&drop computer. thing use audio tracks stored in server clicking on list of available tracks... instead of use <input type="file"> tags. how can read server side files filereader?ajax perhaps? in advance.

this code file reader:

player.prototype.loadfile = function(file, el) {     //console.log(file);     var reader = new filereader,         filetypes = ['audio/mpeg', 'audio/mp3', 'audio/wave', 'audio/wav'],           = this;      if (filetypes.indexof(file.type) < 0) {         throw('unsupported file format!');     }      reader.onloadend = function(e) {         if (e.target.readystate == filereader.done) { // done == 2             $('.progress').children().width('100%');              var onsuccess = function(audiobuffer) {                 $(el).trigger('audiee:fileloaded', [audiobuffer, file]);             },             onerror = function() {                 // on error - show alert modal                 var tpl = (_.template(alertt))({                     message: 'error while loading file ' + file.name + '.'                 }),                 $tpl = $(tpl);                  $tpl.on('hide', function() { $tpl.remove() })                 .modal();           // show modal window                  // hide new track modal                 $('#newtrackmodal').modal('hide');             };              that.context.decodeaudiodata(e.target.result, onsuccess, onerror);         }     };      // note: maybe move different module...     reader.onprogress = function(e) {         if (e.lengthcomputable) {             $progress = $('.progress', '#newtrackmodal');             if ($progress.hasclass('hide'))                 $progress.fadein('fast');              // show loading progress             var loaded = math.floor(e.loaded / e.total * 100);             $progress.children().width(loaded + '%');         }     };      reader.readasarraybuffer(file); };  return player; 

maybe need not think in terms of filereader, create abstraction provides desired functionality , select different implementations based on kind of resource need access. may use xmlhttprequest resources located @ server (an http request), , filereader local files.

you can see similar solution implemented in winamp2-js project: https://github.com/captbaritone/winamp2-js/blob/master/js/my-file.js