I have registration for in React where I need to upload files to the server. Those files needs to be Base64 encoded.

The function to encode it is as follows:

getBase64(file) {

        let document = ;

        let reader = new FileReader();

        reader.readAsDataURL(file);

        reader.onload = function () {

            document = reader.result;

        };

        reader.onerror = function (error) {

            console.log('Error: ', error);

        };



        return document;

    }

And function to handle click on form's next button is as follow:

handleNextButtonClick(event){

    event.preventDefault();

    let data = {domainId: this.props.user[0].domainId, name: steps.stepThree, values: this.state.files};



    let idCard = this.state.files.filter(file => file.file_type === ID_CARD)[0].values.file;

    let statuses = this.state.files.filter(file => file.file_type === STATUTES)[0].values.file;

    let blankLetterHead = this.state.files.filter(file => file.file_type === LETTER_HEAD)[0].values.file;

    let companyPhoto = this.state.files.filter(file => file.file_type === COMPANY_PICTURE)[0].values.file;





    let idCardBase64 = this.getBase64(idCard);

    let statusesBase64 = this.getBase64(statuses);

    let blankLetterHeadBase64 = this.getBase64(blankLetterHead);

    let companyPhotoBase64 = this.getBase64(companyPhoto);

}

If I console log for example the first one this.state.files.filter(file => file.file_type === ID_CARD)[0].values.file; I get

Everything seems ok, but I'm getting error:

Uncaught TypeError: Failed to execute 'readAsDataURL' on 'FileReader': parameter 1 is not of type 'Blob'.

Any idea how to solve this?

UPDATE

let idCardBase64 = idCard ? this.getBase64(idCard) : ;

let statusesBase64 = statuses ? this.getBase64(statuses) : ;

let blankLetterHeadBase64 = blankLetterHead ? this.getBase64(blankLetterHead) : ;

let companyPhotoBase64 = companyPhoto ? this.getBase64(companyPhoto) : ;

I changed it. And in this case exists only idCard. Now I do not get any errors but idCardBase64 is and not Base64 encoded.