How to implement retweet functionality in RoR? - ruby-on-rails

Question

I'm trying to implement retweet functionality on my app.
So I have my retweet_id in my tweets model
tweets schema
| user_id | content | created_at | updated_at | retweet_id
tweets.rb
belongs_to :user
has_many :retweets, class_name: 'Tweet', foreign_key: 'retweet_id'
user.rb
has_many :tweets
And in my tweets controller
tweets_controller.rb
...
def retweet
#retweet = Tweet.new(retweet_params)
if #retweet.save
redirect_to tweet_path, alert: 'Retweeted!'
else
redirect_to root_path, alert: 'Can not retweet'
end
end
Private
...
def retweet_params
params.require(:retweet).permit(:retweet_id, :content).merge(user_id: current_user.id)
end
In my view
tweets/show.html.erb
<%= link_to 'Retweet', retweet_tweet_path(#tweet.id), method: :post %>
My routes
resources :tweets do
resources :comments
resources :likes
member do
post :retweet
end
end
So when I try this I get an error
param is missing or the value is empty: retweet
So I remove .require from 'retweet_params' and that removes that error (though i'm unsure of how wise that is)
Then the link works but won't retweet - reverting to the fallback root_path specified in my action instead.
Unpermitted parameters: :_method, :authenticity_token, :id
Redirected to http://localhost:3000/
I'm not sure what i'm doing wrong. How can I get my retweets working? ty

Answer 1

The reason retweet_params raises an error is because your link link_to 'Retweet', retweet_tweet_path(#tweet.id), method: :post doesn't contain parameters like a new or edit form does. Instead you should create a new tweet that reference to tweet you want to retweet.
before_action :set_tweet, only: %i[show edit update destroy retweet]
def retweet
retweet = #tweet.retweets.build(user: current_user)
if retweet.save
redirect_to retweet, notice: 'Retweeted!'
else
redirect_to root_path, alert: 'Can not retweet'
end
end
private
def set_tweet
#tweet = Tweet.find(params[:id])
end
The above should automatically link the new tweet to the "parent". If this doesn't work for some reason you could manually set it by changing the above to:
retrweet = Tweet.new(retweet_id: #tweet.id, user: current_user)
The above approach doesn't save any content, since this is a retweet.
If you don't want to allow multiple retweets of the same tweet by the same user, make sure you have the appropriate constraints and validations set.
# migration
add_index :tweets, %i[user_id retweet_id], unique: true
# model
validates :retweet_id, uniqueness: { scope: :user_id }
How do we access the content of a retweet? The answer is we get the content form the parent or source (however you want to call it).
There is currently no association that lets you access the parent or source tweet. You currently already have:
has_many :retweets, class_name: 'Tweet', foreign_key: 'retweet_id'
To easily access the source content let's first add an additional association.
belongs_to :source_tweet, optional: true, inverse_of: :retweets, class_name: 'Tweet', foreign_key: 'retweet_id'
has_many :retweets, inverse_of: :source_tweet, class_name: 'Tweet', foreign_key: 'retweet_id'
With the above associations being set we can override the content getter and setter of the Tweet model.
def content
if source_tweet
source_tweet.content
else
super
end
end
def content=(content)
if source_tweet
raise 'retweets cannot have content'
else
super
end
end
# depending on preference the setter could also be written as validation
validates :content, absence: true, if: :source_tweet
Note that the above is not efficient when talking about query speed, but it's the easiest most clear solution. Solving parent/child queries is sufficiently difficult that it should get its own question, if speed becomes an issue.
If you are wondering why I set the inverse_of option. I would recommend you to check out the section Active Record Associations - 3.5 Bi-directional Associations.

Answer 2

Right now the error you're seeing is the one for strong params in Rails. If you can check your debugger or the HTTP post request that's being sent, you'd find that you don't have the params that you're "requiring" in retweet_params
def retweet_params
params.require(:retweet).permit(:retweet_id, :content).merge(user_id: current_user.id)
end
This is essentially saying that you expect a nested hash for the params like so
params = { retweet: { id: 1, content: 'Tweet' } }
This won't work since you're only sending the ID. How about something like this instead?
TweetsController.rb
class TweetsController < ApplicationController
def retweet
original_tweet = Tweet.find(params[:id])
#retweet = Tweet.new(
user_id: current_user.id,
content: original_tweet.content
)
if #retweet.save
redirect_to tweet_path, alert: 'Retweeted!'
else
redirect_to root_path, alert: 'Can not retweet'
end
end
end