Why do I get an InvalidSignature error when uploading multiple images? - ruby-on-rails

Question

I'm new to Rails and I'm trying to save multiple images that come from the front end using a Rails API. I did the ActiveStorage migration but it still gives me the error.
Error:
ActiveSupport: :MessageVerifier::InvalidSignature (ActiveSupport: :MessageVerifier: :InvalidSignature):
app/controllers/posts_controller.rb:20:in ‘create'
Started POST "“/posts" for 172.19.0.1 at 2021-08-05 11:28:13 +0000
Processing by PostsController#create as HTML
Parameters: {"post"=>{"type_id"=>"1", "title"=>"test", "location"=>"calmo", "“category"=>"New Company", "“description"=>"", “images"=>["[object File],[object File],[object File],[
object File]"], "“start_date"=>"2010-03-02", "“end_date"=>"2011-03-02", "“start_time"=>"14:50", "end_time"=>"14:53"}}
User Load (1.0ms) [{"id", 3], ["LIMIT", 1]]
Completed 500 Internal Server Error in 21ms (ActiveRecord: 8.0ms | Allocations: 3822)
server side error
Post.rb
class Post < ApplicationRecord
belongs_to :user
has_many_attached :images
end
posts_controller.rb
def post_params
params.require(:post).permit(:type_id, :category, :title, :location, :description,
:start_date, :end_date, :start_time, :end_time, images: [])
end
index.js
const handleSubmit = (event) => {
event.preventDefault();
const formData = new FormData();
formData.append('post[type_id]', data.type);
formData.append('post[title]', data.title);
formData.append('post[location]', data.location);
formData.append('post[category]', data.category);
formData.append('post[description]', data.description);
formData.append('post[images][]', data.images);
formData.append('post[start_date]', data.startDate);
formData.append('post[end_date]', data.endDate);
formData.append('post[start_time]', data.startTime);
formData.append('post[end_time]', data.endTime);
post(formData, '/posts', function (response) {
alert(response.data);
});
};

Answer 1

Might be a bit late but I had the same problem today and came across this post. Later I figured it out. I did a loop through the images.
Like you, I had like this (using your code above as an example):
formData.append('post[images][]', data.images);
And I kept getting the InvalidSignature error from Rails 7. Then I decided to do a loop:
for (let i = 0; i < data.images.length; i++) {
formData.append('post[images][]', data.images[i]);
}
and the problem was solved for me.