This my code:
#statuses = []
current_user.friends.each do |f|
#statuses = #statuses + f.statuses
end
#sorted_statuses = #statuses.sort_by { |obj| obj.created_at }
I'm taking all my friends statuses from the database and puting them on the wall.
I'm trying to show them from the new (at the top) to the old (at the bottom), buy right now its vice versa. Please let me know how to change it.
No need to pre-declare the array, or post process on another line. the ordering can be done via database. The ruby way is:
#statuses = current_user.friends.order('created_at DESC').collect {|f| f.statuses}
You can even define the default order in your model with default_scope
class Person < ActiveRecord::Base
default_scope order('last_name, first_name')
end
Related
How can I add variables to an existing obejct?
I have a list of chat rooms and I want to add a new variable for each chat to use at my view:
Example I want to add total users of chat
def index
chats_all = ChatRoom.all
#chats = Array.new
chats_all.each |chat|
chat.total_users = 10
#chats << chat
end
#chats
end
total_users is not an attribute of ChatRoom class.
[EDIT - explaim better after #jvillian great awnser]
I don't want total_users as an attribute of User class.
I just want to add as a variable to use at this one single page. For json rails already let my add new attributes to objects. Just need to use as_json().map and a merge()
Example:
def index
chats = chats.as_json().map {
|chat|
chat.merge(
total_users: 10
}
response = { chats: chats }
render json: response
end
Now I got an json with chats and each chat has total_users attribute.
I want to know if I can do something like this with objects, just add a temporary variable to use at index page.
Try
class ChatRoom < ActiveRecord::Base
attr_accessor :total_users
end
You can read more in the docs.
Then, index could look like:
def index
#chats = ChatRoom.all.map do |chat|
chat.total_users = 10
chat
end
end
Alternatively, I would be tempted to do something like:
class ChatRoom < ActiveRecord::Base
TOTAL_USERS = 10
attr_accessor :total_users
def total_users
#total_users || TOTAL_USERS
end
end
And then:
def index
#chats = ChatRoom.all
end
Now, you'll get
#chats.first.total_users
=> 10
You can set total_users to something else if you like, but it will default to 10.
Here's a potential approach using OpenStruct:
def index
#chats = ChatRoom.all.map do |chat|
OpenStruct.new(
chat.
attributes.
merge!(total_users: 10)
)
end
end
Now, you can do:
#chats.each do |chat|
puts chat.total_users
end
which will return 10.
BTW and TBH, I do something like that last sort of thing (using OpenStruct or custom decorators) all the time. In my more recent apps, views never have direct access to models.
Maybe you want to send the response to the view as an array and scan to show informations?
def index
#chats = ChatRoom.all.as_json().map { |chat| chat.merge("total_users" => 10) }
end
Then access #chats, which is actually an array of hashes, view:
<% #chats.each do |chat| %>
<p><%= chat["total_users"] %></p>
<% end %>
You can check how #chats is structured by <p><%= #chats %></p>
I maybe made some syntax error.
To create temporary custom Objects without add new attributes to database Struct solve my problem.
I can create a Struct with chat room info and total users
chat_info = Struct.new(:name, :total_users, :messages)
chat_temp = []
chats = ChatRoom.where(condition)
chats.each do |chat|
chat_temp << chat_info.new("nome", 100, messages)
end
Could someone take a look at my code and let me know if there is a better way to do this, or even correct where I'm going wrong please? I am trying to create a new row for each venue and variant.
Example:
venue_ids => ["1","2"], variant_ids=>["10"]
So, I would want to add in a row which has a venue_id of 1, with variant_id of 10. And a venue_id of 2, with variant_id of 10
I got this working, and it's now passing in my two arrays. I think I am almost there I'm not sure the .each is the right way to do it, but I think that I'm on the right track haha. I have it submitting, however, where would I put my #back_bar.save? because this might cause issues as it won't redirect
Thanks in advance.
def create
#back_bar = BackBar.new
#venues = params[:venue_ids]
#productid = params[:product_id]
#variants = params[:variant_ids]
# For each venue we have in the array, grab the ID.
#venues.each do |v|
#back_bar.venue_id = v
# Then for each variant we associate the variant ID with that venue.
#variants.each do |pv|
#back_bar.product_variant_id = pv
# Add in our product_id
#back_bar.product_id = #productid
# Save the venue and variant to the DB.
if #back_bar.save
flash[:success] = "#{#back_bar.product.name} has been added to #{#back_bar.venue.name}'s back bar."
# Redirect to the back bar page
redirect_to back_bars_path
else
flash[:alert] = "A selected variant for #{#back_bar.product.name} is already in #{#back_bar.venue.name}'s back bar."
# Redirect to the product page
redirect_to discoveries_product_path(#back_bar.product_id)
end
end # Variants end
end # Venues end
end
private
def back_bar_params
params.require(:back_bar).permit(:venue_id,
:product_id,
:product_variant_id)
end
as i said in comments
this is untested code and just showing you how it's possible to do with ease.
class BackBar
def self.add_set(vanue_ids, variant_ids)
values = vanue_ids.map{|ven|
variant_ids.map{|var|
"(#{ven},#{var})"
}
}.flatten.join(",")
ActiveRecord::Base.connection.execute("INSERT INTO back_bars VALUES #{values}")
end
end
def create
# use in controller
BackBar.add_set(params[:venue_ids], params[:variant_ids])
# ...
end
Right now I have this
def index
#trips = Trip.all
end
And I'm outputting data like so:
- #trips.order('created_at desc').first(4).each do |trip|
- trip.trip_images.first(1).each do |image|
= trip.title_name.titleize
However, I have a votable table (from acts_as_votable gem) associated to trips. I was wondering if I can only output trips where trips have a certain amount of votes?
I can get the votes like this:
- #trips.order('created_at desc').first(4).each do |trip|
= trip.get_likes.size #this is where I can get the likes
- trip.trip_images.first(1).each do |image|
= trip.title_name.titleize
EDIT
If I do this instead:
def index
#votes = ActsAsVotable::Vote.where(votable_type: 'Trip').group(:votable_id).count
#trips = Trip.where(#votes)
end
#votes gives me something like this:
{195=>1, 106=>1, 120=>1, 227=>1, 247=>1, 264=>1, 410=>1}
How do I get it where trip will only get the ids?
EDIT 2
I think I figured it out...
def index
#votes = ActsAsVotable::Vote.where(votable_type: 'Trip').group(:votable_id).count
#trips = Trip.where(id: #votes.keys)
end
I got some kind of output. Is there a better way?
Yesterday I answered similar question.
This is how you could get the id(s) of trip with certain amount of votes (you can use =, >, <= and so on):
trip_ids = ActsAsVotable::Vote
.where(votable_type: 'Trip')
.group(:votable_id)
.having('count(votable_id) > 1') #any number of votes
.pluck(:votable_id)
.uniq
Trip.where(id: trip_ids)
Have you considered making this a method in your Trip model?
Something like,
def popular_trip_images
Trip.select(:trip_images).where("likes > ?", 200)
end
Then use it something like,
...
trip.popular_trip_images.each do |image|
...
Edit:
However, I have a votable table (from acts_as_votable gem) associated to trips. I was wondering if I can only output trips where trips have a certain amount of votes?
Sorry, missed this part. The gem has a find_liked_items method but don't see offhand how to set something like liked > 400 etc.
I've been trying to work through the comments, but right now, I've gotten this code to work:
def index
#votes = ActsAsVotable::Vote.where(votable_type: 'Trip').group(:votable_id).count
#votes = #votes.select {|k,v| v > 1}
#trips = Trip.where(id: #votes.keys)
end
If someone else can come up with a better solution! I'll mark as correct.
I'm hacking away at a rails project and I wanted to modify the number of items that end up on a particular page. The page gets populated via an array of items.
For the life of me I can't figure out how to make it show only 2 instead of 4 items.
In the haml file there is this section:
%ul.story-list
- #stories.each do |story|
%li
- unless story.image.blank?
.img-container{ class: ((story.video.blank?)? "": "video-container") }
= image_tag(story.image_url, alt: story.name, class: ((story.video.blank?)? "": "js-has-video"), :video => story.video)
.story-data
%h4= story.name
%h5.location= story.location
%p.quote= story.story
- if story.get_connected?
= link_to 'Get Connected', connect_path
- elsif story.gather_supplies?
= link_to 'Gather Supplies', supplies_path
- elsif story.make_a_plan?
= link_to 'Make a plan', plan_path
The page shows up (on the server) with four story items, I want it to only show two. I was expecting to open the haml file and just delete some lines (or comment them out). I'm so confused.
So, I suspect the number of stories comes from a controller or something like that. ..but maybe it is coming from the placeholder data on the server?
In case you are inspired to help me, all the code is here
https://github.com/city72/city-72
The exact page I'm trying to modify is this one, I want it to only have two stories:
http://collier72.herokuapp.com/stories
Weirdly, in my local environment I can't edit the stories at all. That's what makes me thing the number of items comes from the data.
The stories controller is this tiny little file that doesn't specify the number of stories:
class StoriesController < ApplicationController
after_filter :static_content
def index
all_stories = EmergencyStory.order("index,id ASC").all
#selected_story = all_stories.select {|s| s.selected}.first
#stories = all_stories.collect.select {|s| !s.selected}
end
end
Open up this file:
https://github.com/city72/city-72/blob/master/app/controllers/stories_controller.rb#L8
Change that line from this:
#stories = all_stories.collect.select {|s| !s.selected}
to this:
#stories = all_stories.collect.select{|s| !s.selected}.slice(0,2)
From what I can tell, the fact it is returning 4 isn't intentional, it's just what is in the database. The slice(0,2) will return the first two items.
First, you have 3 stories that you are looking for, not 2. You have your #selected_story and then the remaining #stories. Second, you are retrieving ALL of the stories which will not scale when you get many stories in the database, so rendering this page will slow down over time. So you need to limit the number of records being returned by the database.
Get the selected story.
Then get the two next stories.
class StoriesController < ApplicationController
after_filter :static_content
def index
#selected_story = EmergencyStory.where(selected: true).first
#stories = EmergencyStory.where(selected: false) # don't get selected
.limit(2) # limit records returned
.order("index,id ASC")
.all
end
end
If you were to further refine this you should put those two queries into methods into EmergencyStory.
class StoriesController < ApplicationController
after_filter :static_content
def index
#selected_story = EmergencyStory.selected_story
#stories = EmergencyStory.recent_stories
end
end
class EmergencyStory < ActiveRecord::Base
def self.selected_story
where(selected: true).first
end
def self.recent_stories
where(selected: false).limit(2).order('index,id ASC').all
end
end
I'm writing a zombie survival app, and I'm trying to select all my users marked "alive" where :alive is a boolean.
I was writing a private method in my users controller but can't get the ruby right, does anyone have a pointer?
def get_alive
#holder = (User.map {|user| user})
#user = #holder.each {|i| if i.alive #user << i}
end
thanks
Use a scope to find all alive users.
class User < ActiveRecord::Base
scope :alive, where(:alive => true)
# ... the rest of your model ...
end
Then you can do this:
#alive_users = User.alive
You could just select those users directly if User is active record:
User.where(:alive => true)
Or filter for just those users:
User.all.filter(&:alive)
you need to give a bit more details what "holder" is supposed to be... and why you are comparing against 'i'
otherwise:
User.where(:alive => true)
it's a good idea to wrap this in a scope as in Sean Hill's answer
You can even use this syntax in where query
User.where(alive: true)
Or use select over array of object. But select is slow
User.all.select{ |user| user.alive == true}