如何通过HTTParty通过PUT请求发送空数组？

Question

I have a Photo class that has a "name" attribute and a "tags" attribute. My goal is to implemented an update function in Rails that replaces the photo's tags with whatever was inputted. For example, if I try to PUT a JSON object that has "tags" set to [], I want any tags to be cleared from the photo.

However, when I submit an empty array through HTTParty as one of the body parameters, I believe that HTTParty is translating [] into nil. Therefore the photos#update endpoint on my Rails backend receives nothing for the parameter "tags". I am looking for a way for HTTParty to not convert [] into nil because I lose the ability to remove tags from the photo.

Answer 1

This is a bug/feature in Rails 4, you can read more about the drama at: https://github.com/rails/rails/issues/13420

Your options include:

• One-off hack similar to @mkk's answer
• Upgrade to Rails 5
• Disable deep_munge everywhere, and deal with the consequences of that:

>

# config/application.rb
config.action_dispatch.perform_deep_munge = false

Answer 2

just assign empty array to params, for example:

params[:photo][:tags] ||= []

it will assign empty array if params[:photo][:tags] is not set already. If it doesn't work, it means that you have to adjust keys, for example maybe you do not have :tags, but :tag_ids, then you will have to write params[:photo][:tags]. Just check your HTML structure ( you can always paste it here and I can help you ]. As far as I know this is the standard approach :)