Add null check for placeholder before setting value

[Mte90]

I am using django-file-form because I need an ajax upload but this js code generate an error in the browser as the HTML is different.

[Mte90]

I got the same issue with a custom widget that uploads video in the admin to the same line.

[Mte90]

To help test it, this happens with custom widget that don't have a placeholder above so it generates an error in js that block everything in the page itself.

[Mte90]

why it was closed?

[Mte90]

I have a widget with this HTML:

<div class="bg-white flex flex-none items-center leading-none self-stretch dark:bg-base-900">
    <input type="file" id="{{ widget.attrs.id }}" accept="video/*" class="border border-base-200 bg-white font-medium min-w-20 placeholder-base-400 rounded-default shadow-xs text-font-default-light text-sm focus:outline-2 focus:-outline-offset-2 focus:outline-primary-600 group-[.errors]:border-red-600 focus:group-[.errors]:outline-red-600 dark:bg-base-900 dark:border-base-700 dark:text-font-default-dark dark:group-[.errors]:border-red-500 dark:focus:group-[.errors]:outline-red-500 dark:scheme-dark group-[.primary]:border-transparent disabled:!bg-base-50 dark:disabled:!bg-base-800 px-3 py-2 w-full max-w-2xl " />
</div>

Without that fix I am not able to use it