Working with managed files
In this section, we will look at two examples of working with managed files. First, we will see how we can import product images from our fictional remote JSON-based API. Second, we will see how to create a custom form element that allows us to upload a file and use it in a brand-new CSV-based importer.
Attaching managed files to entities
Now that we have our product image field in place and we can store images, let's revisit our JSON response that contains the product data and assume it looks something like this now:
{
  "products" : [
    {
      "id" : 1,
      "name": "TV",
      "number": 341,
      "image": "tv.jpg"
    },
    {
      "...
