Rails 7 ActionController::UnknownFormat in CommentsController#create respond_to

Question

I have a comments controller that i want to load a partial "create.js.erb"

class CommentsController < ApplicationController
    skip_before_action :verify_authenticity_token
    
    def create
        @comment = Comment.new(comment_params)
        @comment.account_id = current_account.id

        respond_to do |format|
            if @comment.save
                @comments = Comment.where(post_id: @comment.post_id)
                format.js { render "comments/create" }
            else
                # unable to save
            end
        end
    end

    def comment_params
        params.require(:comment).permit(:message, :post_id)
    end
end

My create.js.erb partial

console.log("comment created...");

$("#post-comments").html("<%= escape_javascript(render partial: 'posts/comments', locals: { comments: @comments }) %>");

If i refresh the page the comment gets posted however when i click the submit button it send me the error ActionController::UnknownFormat in CommentsController#create

In laymans terms i want the create function to hit without having to redirect.

Answer 1

Seems like using Hotwire and Turbo is the way to go

respond_to do |format|
   if @comment.save
      @comments = Comment.where(post_id: @comment.post_id)
      format.html { redirect_to posts_path }
      format.turbo_stream
   end
end

then you need to change create.js.erb to create.turbo_stream.erb

<%= turbo_stream.prepend "comments", @comments %>

all works as intended now

Rails 7 removes the previous way of using format.js in Rails UJS and now it's all hotwire/turbo. Kinda confusing but once you learn it no more writing javascript. :)