CODEWITHSUNDEEP
javascriptsettimeoutfilereader
Virtual Device
Virtual Device

Reputation: 2060

setTimeout while reading file

With code below I am reading .csv file:

    var fileInput = document.getElementById("uploaded-file");
    var reader = new FileReader();
    reader.onload = function () {
        var students_data = reader.result.split(/\r?\n|\r/);
        for(var count = 1; count<students_data.length; count++){
               var str_students_information = students_data[count];
               var arr_students_information = str_students_information.split(',');
               var a_student_info = [
                   {name: 'student', value: 'add-student'},
                   {name:"id",value:arr_students_information[0]},
                   {name:"name",value:arr_students_information[1]},
                   {name:"mname",value:arr_students_information[2]},
                   {name:"sname",value:arr_students_information[3]}
               ];
              sendToDatabase(a_student_info);
        }
    };
    reader.readAsBinaryString(fileInput.files[0]);

My goal to achieve is to call method sendToDatabase() every 2 seconds while reading a file. Another way to say, after a line of a document was read call the method and wait 2 seconds before reading next line.
With help of topic setTimeout in for-loop does not print consecutive values I was playing with setTimeout(), but always have not what I need...Probably I am missing something...

Upvotes: 1

Views: 1049

Answers (2)

Barmar
Barmar

Reputation: 781721

Since you want to do something periodically, you should use setInterval(). Instead of a loop, you increment the array index in the callback function.

var fileInput = document.getElementById("uploaded-file");
var reader = new FileReader();
reader.onload = function() {
  var students_data = reader.result.split(/\r?\n|\r/);
  var count = 1;
  var interval = setInterval(function() {
    if (count >= students_data.length) {
      clearInterval(interval);
      return;
    }
    var str_students_information = students_data[count];
    var arr_students_information = str_students_information.split(',');
    var a_student_info = [{
       {name: 'student', value: 'add-student'},
       {name:"id",value:arr_students_information[0]},
       {name:"name",value:arr_students_information[1]},
       {name:"mname",value:arr_students_information[2]},
       {name:"sname",value:arr_students_information[3]}

    ];
    sendToDatabase(a_student_info);
    count++;
  }, 2000);
};
reader.readAsBinaryString(fileInput.files[0]);

Upvotes: 2

Rafael Lima
Rafael Lima

Reputation: 518

I belive this can works: 

for(....) {
 .
 .
 .
  (function(student_info) {
      sendToDatabase(student_info); 
  })(a_student_info);
}

Upvotes: 0

Related Questions