How can I serialize an input File object to JSON?

Question

I want to convert an HTML input file to a JSON string like this:

var jsonString = JSON.stringify(file); console.log( file ); console.log( jsonString ); 

Now, in my Firebug it logs as:

File { size=360195, type="image/jpeg", name="xyz.jpg", mehr...}  Object {} 

Why is the jsonString empty?

Background info: I want to send the file-reference with JSONP to another PHP server.

Additional Information: I want to convert only the file-pointer (reference) to a string, to send it via GET.

Answer 1

It is not possible to directly convert a File object into JSON using JSON.stringify in Chrome, Firefox and Safari.

You can make a work around to convert File object to string using JSON.stringify

Ex:

// get File Object   var fileObject = getFile();  // reCreate new Object and set File Data into it var newObject  = {    'lastModified'     : fileObject.lastModified,    'lastModifiedDate' : fileObject.lastModifiedDate,    'name'             : fileObject.name,    'size'             : fileObject.size,    'type'             : fileObject.type };     // then use JSON.stringify on new object JSON.stringify(newObject); 

You can also add the toJSON() behavior to your File object

EX:

// get File Object   var fileObject = getFile();  // implement toJSON() behavior   fileObject.toJSON = function() { return {    'lastModified'     : myFile.lastModified,    'lastModifiedDate' : myFile.lastModifiedDate,    'name'             : myFile.name,    'size'             : myFile.size,    'type'             : myFile.type  };}     // then use JSON.stringify on File object JSON.stringify(fileObject); 

Note: send a File Object to server using the POST HTTP method.