Is there an alternative for File() constructor for Safari and IE?

I Suggest to use the blob api, I've found the same problem and I solved like that:

var html = <svg>whatever on svg </svg>var fileName = "myfile.svg";var blob = new Blob([html], {type: 'image/svg'});blob.lastModifiedDate = new Date();// var blobAttrs = {type: "image/svg"};// var file = new File([html], fileName, blobAttrs);var formData = new FormData();formData.append("file",blob,fileName);

It is not a "file", but you can use it like it was.

According to web "Can I use" Safari does not support the new File() constructor. See this link http://caniuse.com/#feat=fileapi

So I think you have to either use FileReader or maybe use some of the polyfills listed here https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-Browser-Polyfills

Especially this one could be useful for you https://github.com/mailru/FileAPI (I did not use it myself)

Also have a look at this SO answer What to use instead of FileReader for Safari?

If you can use ES6 classes:

class CustomFile extends Blob{    constructor(blobParts, filename, options) {        super(blobParts, options);        this.name = filename || "";        if(options) {          this.lastModified = options.lastModified;        }    }    lastModified = 0;    name = "";}const blob = new Blob();const fileObject = new CustomFile([blob],"myfile");console.log(fileObject);