Rails:Limiting how many files a user can upload

Question

Users can upload multiple pictures for their posts in my rails app using active storage, is it possible to limit exactly how many photos they can upload in the form?I want to limit it to 4 pictures per user.

<%= f.file_field :images, multiple: true, required: false  %>

Answer 1

You can write custom validation. Add the following code to the related model.

validate :validate_images

private
def validate_images
  return if images.count <= 4

  errors.add(:images, 'You can upload max 4 images')
end

Also you can check the limit on the client side. The following code is from this answer

$(function(){
  $("input[type='submit']").click(function(){
    var fileUpload = $("input[type='file']");
    if(parseInt(fileUpload.get(0).files.length) > 4) {
      alert('You can upload max 4 images');
    }
  });    
});​