Rails WillPaginate::Collection not paginating Array - ruby-on-rails-3

An existing array vparray is being generated, then sorted by a non-db column rate. It then needs to be paginated :
#vps = vparray.sort_by{|e| e.rate}
#vps = WillPaginate::Collection.create(1, 10, #vps.length) do |pager|
pager.replace #vps
end
The view;
<%= will_paginate #vps, :previous_label => "prev ", :next_label => " next" -%>
renders fine, the number of pages pans out and the page is apparently the first. However, upon: <% #vps.each do |product| %>, the entire sorted array is being rendered.
Apparently, the array can only be populated with values of current page. However
#vps = vparray.sort_by{|e| e.rate}
#vps = #vps.paginate(:page => params[:page], :per_page => 10)
#vps = WillPaginate::Collection.create(1, 10, #vps.length) do |pager|
pager.replace #vps
end
is incorrect. The paginate command actually reduces the found set to the same number as per_page and therefore == only 1 page!
So I'm assuming that line should not be there. The view should be calling the proper page of results
<% #vps.each do |product| %>
something better than
<% #vps.page(params[:page]).each do |product| %>
that generates undefined methodpage for WillPaginate::Collection`
context:
ruby 1.9.3,
rails 3.2.17,
will_paginate 3.0.5

Went and re-read the collection.rb and array.rb libraries.
With controller stating:
require "will_paginate/array"
#vgps = vgp.sort_by{|e| e.rate}
#vgps = #vgps.paginate(:page => params[:page], :per_page => 30)
This is all that is necessary for a sorted array.

Related

Why isn't my search method working in Ruby on Rails?

In my Ruby on Rails application, I have a cinema system and am trying to return the screen a showing is in when a user searches for the showing.
To display the search drop down I am using this code in my _application.html.erb:
<%= render( :partial => '/screen_lookup', :locals => {:showings => #showings = Showing.all, :my_path => '/screens/display_screens_by_showing' })%>
Which renders the search from the _screen_lookup.html.erb:
<%= form_tag my_path, :method=>'post', :multipart => true do %>
<%= select_tag ('showings_id'),
options_from_collection_for_select(#showings, :id, :showing_times, 0 ),
:prompt => "Showings" %>
<%= submit_tag 'Search' %>
<% end %>
And uses the display_screens_by_showing in the screens_controller:
def display_screens_by_showing
#screens = Screen.showing_search(params[:showing_id])
if #screens.empty?
# assign a warning message to the flash hash to be displayed in
# the div "feedback-top"
flash.now[:alert] = "There are no films of that genre."
# return all products, in alphabetical order
#screens = Screen.all
end
render :action => "index"
end
And this searches using the method in the screen.rb model:
def self.showing_search(showing_id)
screen = Showing.where("id = ?", showing_id).screen_id
self.where("id = ?", screen)
end
Now, the problem I am having is that because a showing belongs_to a screen, and a screen has_many showings, I need to be able to search for the showing, and store that showing's screen_id in a variable to search for the screen that showing is in with, which I have tried doing in the model:
screen = Showing.where("id = ?", showing_id).screen_id
self.where("id = ?", screen)
But the error I am getting is:
NoMethodError in ScreensController#display_screens_by_showing
undefined method `screen_id' for #<ActiveRecord::Relation []>
These are the model relationships:
showing.rb:
class Showing < ActiveRecord::Base
belongs_to :screen
end
screen.rb:
class Screen < ActiveRecord::Base
has_many :showings
end
What code will get my search working?
The problem is that where doesn't return a record, it returns a relation that can be enumerated or chained, instead you want to use find or find_by to return a single record, which is kind equivalent to where + first
screen = Showing.find(showing_id).screen_id
which is sort of like doing
screen = Showing.where(id: showing_id).first.screen_id
If you want to pass a hash you can use find_by which will be like this
screen = Showing.find_by(id: showing_id).screen_id
PS:
I'm not sure what you're doing exactly, but i think those two lines can be merged into a single query ( not sure what it should be returning, but I'm assuming a screen )
def self.showing_search(showing_id)
Showing.find(showing_id).screen
end

Learning to Search in Rails

I'm trying to create a search form in my rails application. I've looked up various solutions but they make little sense to me.
I'm getting the following error when I run a search through a form in my rails app. Right now my concern (other than the error) is my instance variable #computers in my index action. I'm pretty sure it's not 'the rails way' to get a search done properly and would love some advice.
Error
undefined method `%' for #<Array:0x5780460>
Parameters after Search
http://localhost:3000/computers?utf8=%E2%9C%93&direction=&sort=&search=bob
Search Form
<%= form_tag computers_path, method: "get" do %>
<%= hidden_field_tag :direction, params[:direction] %>
<%= hidden_field_tag :sort, params[:sort] %>
<%= text_field_tag :search, params[:search] %>
<%= submit_tag "Go", name: nil, class: "btn btn-primary" %>
<% end %>
Call to Method
def index
#computers = Computer.where(school_id: current_user.school_id).search(params[:search]).category(params[:category]).order(sort_column + " " + sort_direction)
end
Method
def Computer.search(search)
if search
search = search.downcase
params = []
values = {}
column_names.each do |c|
params << "#{c} LIKE #{c.to_sym}"
values[c.to_sym] = search
end
params.join (' OR ')
where(params,values)
else
all
end
end
You've got the right idea, but invoking the .join method does not change the object on which it is called, it merely returns a string representation. You need to store the return in a variable, something like this: paramsStr = params.join(' OR '). Then simply pass paramsStr to the where clause.
Ultimately, that is what is causing your unidentified method % for Array .... error; this version of the where method is expecting the first parameter to be a string. Check out this documentation, the part about placeholder conditions.
Hope that helps.

rails OR query based on multiple checkbox selections

This seems like it should be a common problem but I'm having trouble finding an answer. Basically I want to have a form with 10 or so checkboxes which I'm creating with check_box_tag. When the form is submitted I want to generate a query that return all records that match ANY of the checked selections. So, the number of checked selections will vary.
So, for example, if I have
class Book < ActiveRecord::Base
belongs_to :author
end
I want to generate something like
Book.where("author_id = ? or author_id = ?", params[authors[0]], params[authors[1]]) if there are two boxes checked, etc.
Thanks for any insight.
Will this work for you?
Book.where(author_id: [array_of_author_ids])
You need to collect author_ids from params first
I recently had to do something similar, this is how I achieved this. It's pretty clever (at least I think so. :))
I created a query model that serializes the query column (text field) in JSON. I use a form to get the query data from the user with selection fields.
class BookQuery < ActiveRecord::Base
has_many :books
# loop through each foreign key of the Book table and create a hash with empty selection
def self.empty_query
q = {}
Book.column_names.each do |column_name|
next unless column_name.ends_with?("_id")
q.merge column_name => []
end
end
end
I'm using Author as an example below:
<%= form_for #book_query do |f| %>
<% for author in Author.all %>
<%= check_box_tag "book_query[query][author_ids][]", author.id, false%>
<%= author.name %>
<% end %>
<%= f.submit "Save Query" %>
<% end %>
When this form is submitted you ended up with parameters like this:
When the form is submitted it generates this parameter:
Parameters: {"utf8"=>"✓", "authenticity_token"=>"XXXXXXXXXXX", "book_query"=>{"query"=>{"author_ids"=>["2", "3"]}}, "commit"=>"Save Query"}
Now in the BookQuery controller's create action you can just do what create function always does:
def create
#book_query = BookQuery.build(params[:book_query])
if #book_query.save
flash[:success] = "Book query successfully saved."
redirect_to ...
else
flash[:error] = "Failed to save book query."
render :new
end
end
But by default rails serializes the data in hash type:
1.9.3p194 :015 > pp BookQuery.find(9).query
BookQuery Load (0.7ms) SELECT "book_queries".* FROM "book_queries" WHERE "book_queries"."id" = $1 LIMIT 1 [["id", 9]]
"--- !ruby/hash:ActiveSupport::HashWithIndifferentAccess\nauthor_ids:\n- '2'\n- '3'\n"
=> "--- !ruby/hash:ActiveSupport::HashWithIndifferentAccess\nauthor_ids:\n- '2'\n- '3'\n"
In BookQuery model, add the following:
serialize :query, JSON
But rail would change the IDs to string:
1.9.3p194 :018 > query = JSON.parse(BookQuery.find(10).query)
BookQuery Load (0.5ms) SELECT "book_queries".* FROM "book_queries" WHERE "book_queries"."id" = $1 LIMIT 1 [["id", 10]]
=> {"author_ids"=>["2", "3"]}
1.9.3p194 :019 > query["author_ids"]
=> ["2", "3"]
What I did then is override the attribute accessors in BookQuery model:
The below has to be done because the hash returns strings, not ids in integer.
def query=(query)
query.each_pair do |k, v|
if query[k].first.present?
query[k].map!(&:to_i)
else
query.except!(k)
end
end
write_attribute(:query, query)
end
# just want to avoid getting nil query's
def query
read_attribute(:query) || {}
end
To find book with this query, you can simply add this function to your Book model:
def self.find_by_book_query(book_query, options = {})
options[:conditions] = book_query.query
find(:all, options)
end
Now you get a customizable query string based on the model definition Book and everything works like the Rails way. :)

Rails filtering with acts_as_taggable gem

I am working the acts-as-taggable-on gem and have a question about how to filter down search results based on tags users select. Here's an abridged look at my controller:
class PhotosController < ApplicationController
def index
#photos = Photo.where(["created_at > ? AND is_approved = ?", 1.months.ago, true])
#tags = ["Animals", "Architecture", "Cars", "Flowers", "Food/Drink", "General", "Landscape", "Mountains", "Nature"]
end
def search_by_tag(tag)
#photos = Photo.where('tagged_with LIKE ?', tag)
end
end
Photos/index
<% #tags.each do |tag| %>
<%= link_to tag, {:search_by_tag => tag}, :class => "tag" %>
<% end %>
This lists out all of the tags from the hash #tags defined in index, but clicking them doesn't actually filter anything down. Here's a look at what clicking one of those links produces in the log:
Started GET "/photos?search_by_tag=Animals" for 127.0.0.1 at Sun Oct 09 17:11:09 -0400 2011
Processing by PhotosController#index as HTML
Parameters: {"search_by_tag"=>"Animals"}
SQL (0.5ms) SELECT name FROM sqlite_master WHERE type = 'table' AND NOT name = 'sqlite_sequence'
The result I want is for the page to display only Photos that are tagged_with whichever tag was clicked on. I can't quite figure out how to accomplish this.
(Side-question: I can't seem to find a way to list out all of the tags from the tags table that acts-as-taggable-on generated. Doing something like Photo.tagged_with or Photo.tags doesn't work. I am able to see the "tags" table the gem created, and the entries inside of it; I'm just not really clear how to handle that using this gem)
Any thoughts greatly appreciated.
UPDATE
I've updated my code and am a bit closer.
class PhotosController < ApplicationController
def search_by_tag
#photos = Photo.tagged_with(params[:tag_name])
end
photos/index
<% Photo.tag_counts_on(:tags).map(&:name).each do |tag| %>
<%= link_to tag, {:action => 'search_by_tag', :tag_name => tag}, :class => "tag" %>
<% end %>
I believe this is closer, but still working through this...
You have a number of errors in your code:
Your link_to call is actually calling the index action.
Your search_by_tag method is expecting an argument, where it should be using the params hash to access the parameters passed to it in the web request.
tagged_with is a class method added by acts_as_taggable_on, not a field in your table - therefore you can't use it in the where method like you have done.
Finally, to get all the tag names: Photo.tag_counts_on(:tags_or_whatever_you_tagged_on).map(&:name)
Take a look at the acts_as_taggable_on documentation and you'll see examples of how to use tag_counts_on and tagged_with.
As for the Rails things: http://guides.rubyonrails.org/ http://railsforzombies.org/ and/or http://railscasts.com/

Month pagination with kaminari

I want to paginate posts by month so I added following scope in Post model
class Post
include Mongoid::Document
include Mongoid::Timestamps
scope :by_month, lambda {|end_date| Post.order_by(:created_at => :asc).where(:created_at.gte => (end_date.to_date.beginning_of_month), :created_at.lte => (end_date.to_date))}
end
In my controller I put
def show
#posts = Post.by_month(Time.now).page(params[:page]).per(20)
end
In view
<%= paginate #posts, :theme => 'month_theme' %>
<%= render #posts %>
Problems:
pagination is not working by month, I want to show all result of a month in a page, replacing params[:page] by params[:month]=2 or params[:month]=Feb
How do I view 'August 2011' instead of 1,2
Loop month and year like when you goto previous while in 'Jan 2011' it will goto 'Dec 2010'
I suppose this is not really a matter of pagination. Dealing with the params[:month] value for the query is something different from the page offset switching. You might not need a pagination library for that.
How about simply creating those links like this?
controller:
#posts = Post.by_month(Time.parse(params[:month]) || Time.now)
view:
<% Post.only(:created_at).map {|p| p.created_at.to_date.beginning_of_month}.uniq.sort.each do |m| -%>
<%= link_to_unless_current m, :month => m %>
<% end -%>
Of course you can combine this query with normal pagination if needed. But the pagination links should not be mixed with the month links in that case.