javascript - Running private method out of an other method -

i initialize following code class readconfig:

var myreadconfig = new readconfig();

this works fine , alert("2") appears.

after run statement window.requestfilesystem(...) calls method gotfsreader. never see alert("3"); result.

how should run method gotfsreader out of window.requestfilesystem(...) ? if run outside of class works completely...

my class:

  var readconfig = function(){         var path = "zugangsdaten.txt";         window.requestfilesystem(localfilesystem.persistent, 0, gotfsreader, failreader);         alert("2");          var gotfsreader = function(filesystem) {             alert("3");             filesystem.root.getfile(path, null, gotfileentryreader, failreader);          }          var gotfileentryreader = function(fileentry) {             fileentry.file(gotfilereader, failreader);             alert("4");         }          var gotfilereader = function(file){             readastext(file);         }          var readastext = function(file) {             var reader = new filereader();             reader.onloadend = function(evt) {                 console.log("read text");                 handlelocalpasswort(evt.target.result);             };             reader.readastext(file);         }          var failreader = function(evt) {             console.log(evt.target.error.code);         }          var handlelocalpasswort = function(filestr){             if(filestr=="" || filestr == null){                 return;             }              var arrayitems = filestr.split(";");             document.getelementbyid('tb_benutzer').value = arrayitems[0];             document.getelementbyid('tb_password').value = arrayitems[1];             document.getelementbyid('tb_knr').value = arrayitems[2];             checklogin();          }     } 

your code structured incorrectly. you're not initializing variable ("gotfsreader") until after pass value function. therefore, you're passing undefined, , not reference function.

move window.requestfilesystem() call after initialization, or declare functions function declaration statements:

    function gotfsreader(filesystem) {         alert("3");         filesystem.root.getfile(path, null, gotfileentryreader, failreader);     } 

if that, it'll work, because function declaration statements treated if occur @ beginning of containing function.

variable declarations hoisted, there's difference: actual declaration part of var statement treated if occurs @ start of function. initialization done @ point in function var appears. thus, in code, variable called "gotfsreader" declared @ point call requestfilesystem(), it's not yet initialized.