Type error - Object is possibly 'null' for event object

Question

In my angular app i am using this function below.

@HostListener('drop', ['$event'])
    onDrop(event: DragEvent): void {
        const textData = event.dataTransfer.getData('text');
        this.inputElement.focus();
        this.pasteData(textData);
        event.preventDefault();
}

Tslint is complaining here event.dataTransfer. I am getting this error - Returns the DataTransfer object for the event. Object is possibly 'null'.

Answer 1

This is common if you turned on error catching by TSLint.

you can use any of the below.

if(event.dataTransfer != undefined){
    const textData = event.dataTransfer.getData('text');
}

Or simply (note the ?)

const textData = event.dataTransfer?.getData('text');