handleUpload(){
        if(this.selectedFilesToUpload.length > 0) {
            this.showSpinner = true;
            
            this.file = this.selectedFilesToUpload[0];
            this.fileReaderObj = new FileReader();

            this.fileReaderObj.onloadend = (() => {
                let fileContents = this.fileReaderObj.result;
                fileContents = fileContents.substr(fileContents.indexOf(',')+1)
                let sliceSize = 1024;           
                let byteCharacters = atob(fileContents);
                let bytesLength = byteCharacters.length;
                let slicesCount = Math.ceil(bytesLength / sliceSize);                
                let byteArrays = new Array(slicesCount);
                for (let sliceIndex = 0; sliceIndex < slicesCount; ++sliceIndex) {
                    let begin = sliceIndex * sliceSize;
                    let end = Math.min(begin + sliceSize, bytesLength);                    
                    let bytes = new Array(end - begin);
                    for (let offset = begin, i = 0 ; offset < end; ++i, ++offset) {
                        bytes[i] = byteCharacters[offset].charCodeAt(0);                        
                    }
                    byteArrays[sliceIndex] = new Uint8Array(bytes);                    
                }
 
                this.myFile =  new File(byteArrays, this.fileName, { type: this.fileType });

                let reader = new FileReader();
                reader.onloadend = (() => {
                    let base64data = reader.result;
                    this.base64FileData = base64data.substr(base64data.indexOf(',')+1); 
                    this.fileUpload();
                });
                reader.readAsDataURL(this.myFile);                                 
            });
            this.fileReaderObj.readAsDataURL(this.file);            
        }
        else {
            this.fileName = 'Upload any file';
        }
    }