How can I create an ActiveRecord Query for the following Sql query
SELECT device1.*
FROM devices device1
WHERE device1.id = (SELECT MAX(device2.id)
FROM devices device2
WHERE device2.user_id = device1.user_id);
I have Device model with user_id column
I dont want to user find_by_sql because it returns Array instead ActiveRecord Array
I have a problem I need write validator in rails to checking an email is real or fake? I try to research but nothing. Can someone help me? Thanks !
I know what is causing this issue, but can't find the working alternative of it. I will describe the problem and hope for a good answer.
So, I have a bootstrap modal in which i have a form. that form _for is calling GalleryController#create method.. this is my modal -->
#gallery_create_modal.modal.fade.m{'tabindex':-1 , 'role':'dialog','aria-labelledby':'creategallery'}
.modal-dialog.modal-lg{'role':'document'}
.modal-content
=form_for @gallery , html: {multipart: true} do |f|
...content
=f.submit 'Upload' , class: 'btn btn-primary'
and here is my gallery controller
class GalleriesController < ApplicationController
before_action :authenticate_amitian!
def create
@gallery = current_amitian.create_gallery(gallery_params)
end
private
def gallery_params
params.require(:gallery).permit(:g1,:g2,:g3,:g4,:g5,:g6,:amitian_id)
end
end
upto this point if I run the code it returns error saying first element of form can't be empty or nil... means my @gallery is nil
this is because my modal is in my Amitians#show page so to solve this I had to initialize my @gallery inside Amtians#show method like this -->
class AmitiansController < ApplicationController
before_action :authenticate_amitian!, except: [:show]
def index
...content
end
def show
....
@gallery = current_amitian.build_gallery
....
end
This takes away the error but everytime I refresh my page after upload.. it updates my sql table's Gallery.amitian_id to NULL
I can't seem to find a sol. please help. Thank you.
I am currently facing the following problem: Users are able to create activities. Other users have the possibility, to participate the activity. I now want that the users, which already participated to an activity are going to be listed in the view of the activity. So what I try is to show all the users that participated for an activity in the show method of the activity_controller with an activity_id.
The relations of the models are as follows:
class Activity < ActiveRecord::Base
has_many :users, through: :participations
belongs_to :user
has_many :participations
has_many :reviews
end
class Participation < ActiveRecord::Base
belongs_to :user
belongs_to :activity
has_many :activities
end
class User < ActiveRecord::Base
has_many :activities
has_many :participations
has_many :reviews
end
My activity controller ist doing the following:
class ActivitiesController < ApplicationController
before_action :set_activity, only: [:show, :edit, :update, :destroy]
before_action :authenticate_user!, except: [:show]
def index
@activities = Activity.all
end
def show
@participated = Participation.where("activity_id = ? AND user_id = ?", @activity.id, current_user.id).present? if current_user
@reviews = @activity.reviews
@hasReview = @reviews.find_by(user_id: current_user.id) if current_user
@participant = Participation.where (:activity_id == 'activity_id')
end
def new
@activity = current_user.activities.build
end
def create
@activity = current_user.activities.build(activity_params)
if @activity.save
redirect_to edit_activity_path(@activity), notice: "We want to give you a warm welcome!"
else
render :new, notice: "Something seems to be missing!"
end
end
def edit
if current_user.id == @activity.user.id
redirect_to root_path
end
end
def update
if @activity.update(activity_params)
redirect_to edit_activity_path(@activity), notice: "Updated!"
else
render :edit
end
end
def destroy
@activity = Activity.find(params[:id])
if @activity.destroy
redirect_to activities_path, notice: "Deleted!"
end
end
private
def set_activity
@activity = Activity.find(params[:id])
end
def activity_params
params.require(:activity).permit(:activity_name,
:activity_starttime,
:activity_duration,
:activity_intensity,
:activity_distance,
:activity_topography,
:activity_address,
:activity_track,
:activity_summary)
end
end
Meanwhile the participations controller handles this:
class ParticipationsController < ApplicationController
before_action :authenticate_user!
def preload
activity= Activity.find(params[:activity_id])
participations = activity.participations
render json: participations
end
def create
if Participation.exists?(user_id: current_user.id)
redirect_to activities_path(@activity), notice: "Du nimmst bereits teil!"
else
@participation = current_user.participations.create(participation_params)
redirect_to @participation.activity, notice: "Klasse, du nimmst nun teil!"
end
end
def participant
@participant = user.participations
end
def your_matches
@matches = current_user.participations
end
def your_participations
@activities = current_user.activities
end
private
def participation_params
params.permit(:activity_id, :status)
end
end
In my view, I called the controller by using:
<div class="row">
<div class="col-md-12">
<h3>Wer kommt bis jetzt mit? </h3>
<table>
<tr>
<th></th>
</tr>
<% @participant.each do |participant| %>
<tr>
<td><%= participant.user.fullname %></td>
</tr>
<% end %>
</table>
</div>
</div>
Which gives me a list of all users that participated for any activity. But the only thing I want now is to show all the users which participated for the activity requested. I would say that my relations should work properly, therefore I guess I just need a small hint to solve the problem. At another point of my app I already got a list, where I am able to show the users which participated, but because of the different controllers, I am not able to call this from the activity controller. All in all, this causes an error because I am not able to call the participations_controller from an activitities_view.
<div class="panel-body">
<% @activities.each do |activity| %>
<% activity.participations.each do |participation| %>
<div class="row">
<div class="col-md-3">
<%= link_to user_path(participation.user) do %>
<%= participation.user.fullname %>
<% end %>
</div>
Would really appreciate any help and thanks in advance!
I am facing a problem while working with Action Cable, whenever I run my program I receive an error that says 'Subscription Class not found 'ConversationChannel'
and when I try to send a message I get this log
Successfully upgraded to WebSocket (REQUEST_METHOD: GET, HTTP_CONNECTION: Upgrade, HTTP_UPGRADE: websocket)
Subscription class not found: "ConversationChannel"
Could not execute command from {"command"=>"message", "identifier"=>"{\"channel\":\"ConversationChannel\"}", "data"=>"{\"message\":[{\"name\":\"conversation_id\",\"value\":\"2\"},{\"name\":\"amitian_id\",\"value\":\"1\"},{\"name\":\"body\",\"value\":\"nmm\"}],\"action\":\"speak\"}"}) [RuntimeError - Unable to find subscription with identifier: {"channel":"ConversationChannel"}]: C:/RailsInstaller/Ruby2.3.0/lib/ruby/gems/2.3.0/gems/actioncable-5.0.1/lib/action_cable/connection/subscriptions.rb:74:in `find' | C:/RailsInstaller/Ruby2.3.0/lib/ruby/gems/2.3.0/gems/actioncable-5.0.1/lib/action_cable/connection/subscriptions.rb:53:in `perform_action' | C:/RailsInstaller/Ruby2.3.0/lib/ruby/gems/2.3.0/gems/actioncable-5.0.1/lib/action_cable/connection/subscriptions.rb:17:in `execute_command' | C:/RailsInstaller/Ruby2.3.0/lib/ruby/gems/2.3.0/gems/actioncable-5.0.1/lib/action_cable/connection/base.rb:88:in `dispatch_websocket_message' | C:/RailsInstaller/Ruby2.3.0/lib/ruby/gems/2.3.0/gems/actioncable-5.0.1/lib/action_cable/server/worker.rb:58:in `block in invoke'
I will give my channel.rb and other js files
Here is my ConversationChannel.rb
class ConversationChannel < ApplicationCable::Channel
def subscribed
# stream_from "some_channel"
stream_from "conversations-#{current_amitian.id}"
end
def unsubscribed
# Any cleanup needed when channel is unsubscribed
stop_all_streams
end
def speak(data)
message_params = data['message'].each_with_object({}) do |el, hash|
hash[el.values.first] = el.values.last
end
ActionCable.server.broadcast(
"conversations-#{current_amitian.id}",
message: message_params
)
end
end
Here is my conversation.js
App.conversation = App.cable.subscriptions.create("ConversationChannel", {
connected: function() {
},
disconnected: function() {
},
received: function(data) {
console.log(data['message']);
},
speak: function(message) {
return this.perform('speak' , {
message: message
});
}
});
$(document).on('submit', '.new_message', function(e) {
e.preventDefault();
var values = $(this).serializeArray();
App.conversation.speak(values);
$(this).trigger('reset');
});
This is my connection.rb
module ApplicationCable
class Connection < ActionCable::Connection::Base
identified_by :current_amitian
def connect
self.current_amitian = find_verified_amitian
end
protected
def find_verified_amitian
if(current_amitian = env['warden'].amitian)
current_amitian
else
reject_unauthorized_connection
end
end
end
end
using the log file given above can anyone tell me why It can't find my conversation_channel.rb file ?
Thank you
Learning programming on my own, need some guidance on best platform/tool/language and libraries to build application my own application that monitors, sends and pulls out information (i.e. server logs, data from monitoring tools) from multiple linux servers. ideally i want a client program that keeps pushing the data to sever from where i can show on the web interface.
Hi everyone and thanks for the great work. I have a problem with rails : I created a fresh app nicely running on port 3000. I'm trying to reate a nw controller using "rails generate controller Welcome index" and rails is throwing this :
Ignoring bindex-0.5.0 because its extensions are not built. Try: gem pristine bindex --version 0.5.0
/usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/spec_set.rb:87:in `block in materialize': Could not find nokogiri-1.8.0 in any of the sources (Bundler::GemNotFound)
from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/spec_set.rb:81:in `map!'
from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/spec_set.rb:81:in `materialize'
from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/definition.rb:159:in `specs'
from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/definition.rb:218:in `specs_for'
from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/definition.rb:207:in `requested_specs'
from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/runtime.rb:109:in `block in definition_method'
from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/runtime.rb:21:in `setup'
from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler.rb:101:in `setup'
from /usr/lib64/ruby/gems/2.3.0/gems/bundler-1.15.0/lib/bundler/setup.rb:20:in `<top (required)>'
from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/commands.rb:33:in `<module:Spring>'
from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/commands.rb:4:in `<top (required)>'
from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/server.rb:9:in `<top (required)>'
from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /usr/lib64/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/client/server.rb:9:in `call'
from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/client/command.rb:7:in `call'
from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/lib/spring/client.rb:30:in `run'
from /usr/lib64/ruby/gems/2.3.0/gems/spring-2.0.2/bin/spring:49:in `<main>'
Does someone have an idea of what this could be ? I cannot figure it out and I will appreciate any help. My OS is opensuse tumbleweed.
Thanks.