Javascript unobtrusive onclick with sweetalert

Question

Good Evening,

I'm fairly new to JavaScript. I have a book and scour the internet when looking for answers. I see that the JavaScript landscape seems to have a plethora of paths and frameworks. To the question, I'm trying to use unobtrusive javascript with sweetalert. I had an issue with onclick finishing the function before an option was selected. I altered the function to return false by default and let the path nullify the onlick function and click the button. Is the following reasonable form ? Or would another method be recommended for the same effect? If so, please indicate why its better. Also, no framework/library answers for the moment please.

window.onload = function() {

    function doSomething() {
        var button = document.getElementById("edit");
         swal({
            title: 'Are you sure?',
            text: 'You will not be able to recover this imaginary file!',
            type: 'warning',
            showCancelButton: true,
            confirmButtonText: 'Yes, Update it!',
            cancelButtonText: 'No, stop'
        }).then((result) => {
            if (result.value) {
                button.onclick = null;
                button.click();
                // For more information about handling dismissals please visit
                // https://sweetalert2.github.io/#handling-dismissals
            } else if (result.dismiss === swal.DismissReason.cancel) {
                swal(
                    'Cancelled',
                    'No Update Occured :)',
                    'error'
                )


            }
        })
        return false;
    }
   document.getElementById("edit").onclick = doSomething;

 <form action="{{route('categories.update',$cat->id)}}" method="post">
                {{method_field('patch')}}


                <div class="form-group">
                    <label for="title">Name</label>
                    <input type="text" name="name" class="form-control" value="{{$cat->name}}">
                    <label for="description">Description</label>
                    <input type="text" name="description" class="form-control" value="{{$cat->description}}">

                </div>


                <button class="btn btn-primary" type="submit" id="edit">Edit Category</button>
                {{@csrf_field()}}
            </form>