c# - Get image in upload field in Shadowbox to upload after parent submit? -

parent page includes form, button triggers shadowbox child.

shadowbox child includes form that, after submit, populates hidden parent form data. non-image data easy.

how 1 handle images? in other words, how propagate image to-be-uploaded shadowbox parent, then upload after parent form has been submitted?

the tags chosen because i'm working languages.

the easiest way found solve using this answer, took serious digging.

essentially, using onchange event on input file field, save base64 encoded version of image user browsed in variable in parent page.

shadowbox page:

// in js $('[type=file]').change(function () {     if (input.files && input.files[0])     {         var reader = new filereader();          reader.onload = function (e)         {             // parent var gets encoded image.             self.parent.hiddenelement.val(e.target.result);         }          reader.readasdataurl(input.files[0]);     } } 

parent page:

// html <input type='hidden' name='encoded_image' />  // in js var hiddenelement = $('[name=encoded_image]'); 

this base64 encoded image can saved blob storage on server after parent page's form submitted.