How can I set JQuery JCrop preview for cropping after fileupload?

Question

I am working with JCrop jquery library, I am providing preview of image after uploading the file using HTML file control.

view part (demo data)

<input type="file" id="photograph" />
<img src="#" id="target" />

Javascript code

// for setting img src
function readURL(input) { 
    console.log("readURL");
    if (input.files && input.files[0]) {
        var reader = new FileReader();

        reader.onload = function (e) {
            $('#target').attr('src', e.target.result);
            console.log("inside if =>"+e.target.result);       
        }

        console.log("outside IF");
        reader.readAsDataURL(input.files[0]);

    }
}

// for setting pre-selected cropping area
function setProperties(){ 
   console.log("set properties");

   $('#target').Jcrop({         
              setSelect: [0,12,23,43]
        }); 

}

// on change event for fileupload
$("#photograph").change(function(){ 
    console.log("change event called!");
    readURL(this);
    setProperties();
});

output

 change event called!
 readURL
 outside IF
 set properties
 inside if=>data:image/jpeg;base64,/9j/4gIcSUNDX1BST0ZJTEUAAQEAAAIMbGNtcwIQAABtbnRyUkdC…sXK2t+4UdmuSVl64hb2gMHh1Nhm83DAdQJniIM6eZUxzuYCR2my3FSwGpVbzBdwlgrrc/

I want to set some properties after uploading the image file, but "inside if=>" [see the output posted above] is getting called at the very end. so why is this happening? and How should I tackle this issue?

Answer 1

You have to call setProperties after image source setted and image loaded

function readURL(input) { 
    console.log("readURL");
    if (input.files && input.files[0]) {
        var reader = new FileReader();

        reader.onload = function (e) {
            $('#target').attr('src', e.target.result);
            console.log("inside if =>"+e.target.result); 
            // Call after source setted and image file loaded
            setProperties();      
        }

        console.log("outside IF");
        reader.readAsDataURL(input.files[0]);

    }
}