Ajax请求中的表单数据不完整

Question

Stucked in this situation:
I upload several inputs fields and images using ajax. Images are encoded to base64 string with FileReader api. Everything seems to work except sending encoded images.

My code (simplified):

var groups = {},
    objects = {};
objects["name"] = {},
objects["group"] = {};
objects["image"] = {};

var objectCount = $(".layout-object").length;
$(".layout-object").each(function(i,v) {
   var k = objectCount-i;
   objects["name"][i] = $(v).val();
   objects["group"][i] = $("#set-object-dropdown-"+k).val();

   // get an image
   var file = document.getElementById('image-'+k).files[0];

   var reader = new FileReader();
   reader.onload = function(event) {  
      objects["image"][i] = event.target.result; // get image in base64
   };
   reader.readAsDataURL(file);
});             

$(".layout-group").each(function(i,v) {
    groups[i] = $(v).val();
});

// prepare object for ajax request...
var data = {
    name: $("#name").val(),
    groups: groups,
    objects: objects
};

// console log shows all data correctly in place = in objects there is a propery "image"...
console.log(data);

// sending ajax POST request
var posting = $.post( location.href, { data: data } );
posting.done(function(response){
        console.log(response);
});

Issue: in ajax request form data property "image" is missing, but before posting object with data is correct.

Maybe is there a problem with readAsDataURL function and its onload event?

Answer 1

Something like this:

reader.onload = function(event) {  
  objects["image"][i] = event.target.result; // get image in base64
  if (k == 1) //when the last object is iterated and it's image is set:
  {
     fireAjax();
  }

};

function fireAjax(){
    // sending ajax POST request
    var posting = $.post( location.href, { data: data } );
    posting.done(function(response){
            console.log(response);
    });
}