File selector for js/ts

file_handlers.ts

export async function open_file({ accept }: { accept?: string }): Promise<File> {
	const input = document.createElement('input');
	input.type = 'file';
	if (accept) input.accept = accept;
	input.click();

	return new Promise((resolve, reject) => {
		input.onchange = () => {
			const file_handle = input.files?.[0];

			if (file_handle) {
				resolve(file_handle);
			} else {
				reject(new Error('No file selected'));
			}

			input.remove();
		};
	});
}


export async function save_file(
  content: Blob | string,
  filename: string,
  options?: { type?: string }
): Promise<void> {
  const blob = content instanceof Blob ? content : new Blob([content], options);

  const url = URL.createObjectURL(blob);
  const a = document.createElement('a');
  a.href = url;
  a.download = filename;

  // Append the anchor to the body (required for Firefox)
  document.body.appendChild(a);

  a.click();

  // Clean up
  setTimeout(() => {
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
  }, 0);
}