Rails How to pass params in cross model system - ruby-on-rails

Question

I am unable to figure out the method to pass params to a link tag. What I want to do is When someone clicks on the Join Group link, the Membership model shall have a new row with group_id as the current group id and the user id as the current user id. The Membership model currently consists of two columns : user_id and group_id that maps users to groups. Can anyone help me with the mistake I am making.
Here is the code
Groups : show.html.erb
<p id="notice"><%= notice %></p>
<p>
<strong>Title:</strong>
<%= #group.title %>
</p>
<p>
<strong>Desc:</strong>
<%= #group.desc %>
</p>
<p>
<strong>Creator:</strong>
<%= #creator.first_name %>
</p>
<%= link_to 'Join Group', memberships_path(:group_id => #group.id, :user_id => current_user.id ), method: :post %>
<%= link_to 'Edit', edit_group_path(#group) %> |
<%= link_to 'Back', groups_path %>
and here is the Memberships controller
class MembershipsController < ApplicationController
before_action :set_membership, only: [:show, :edit, :update, :destroy]
# GET /memberships
# GET /memberships.json
def index
#memberships = Membership.all
end
# GET /memberships/1
# GET /memberships/1.json
def show
#membership = Membership.find(params[:id])
#user = User.find(#membership.user_id)
#group = Group.find(#membership.group_id)
end
# GET /memberships/new
def new
#membership = Membership.new
end
# GET /memberships/1/edit
def edit
end
# POST /memberships
# POST /memberships.json
def create
#membership = Membership.new(membership_params)
respond_to do |format|
if #membership.save
format.html { redirect_to #membership, notice: 'Membership was successfully created.' }
format.json { render :show, status: :created, location: #membership }
else
format.html { render :new }
format.json { render json: #membership.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /memberships/1
# PATCH/PUT /memberships/1.json
def update
respond_to do |format|
if #membership.update(membership_params)
format.html { redirect_to #membership, notice: 'Membership was successfully updated.' }
format.json { render :show, status: :ok, location: #membership }
else
format.html { render :edit }
format.json { render json: #membership.errors, status: :unprocessable_entity }
end
end
end
# DELETE /memberships/1
# DELETE /memberships/1.json
def destroy
#membership.destroy
respond_to do |format|
format.html { redirect_to memberships_url, notice: 'Membership was successfully destroyed.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_membership
#membership = Membership.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def membership_params
params.require(:membership).permit(:user_id, :group_id)
end
end

Answer 1

You should have a method in your controller that handles adding a user to a group, something like:
class MembershipsController < ApplicationController
...
def join_group
#user = User.find(params[:user]
#user.group_id = params[:group_id].to_i
end
...
end
Then routes.rb needs a path to that controller method:
get 'memberships/join_group' => 'memberships#join_group'
which will result in a path like memberships_join_group_path that you will use in your link_to:
<%= link_to 'Join Group', memberships_join_group_path(:group_id => #group.id, :user_id => current_user.id ) %>
The path you're currently using is sending params to your index method.

Answer 2

try
def create
#member = current_user.members.build(:group_id => params[:group_id])
if #member.save
flash[:notice] = "You have joined this group."
redirect_to members_path
else
flash[:error] = "Unable to join."
redirect_to members_path
end
end
and use memberships instead of members