Need two buttons to index either all items or items current user is assigned?

Question

Ruby 2.0.0, Rails 4.0.3, jquery-datatables-rails 2.2.3 (DataTables 1.10.2)

I would like to have two buttons on my form, one to display all items and another to display only those items currently assigned to the current user. Given that I am even going down the right path for this, and I am not certain I am, I have two issues. Or am I on the wrong path?

In the controller action, I am attempting to pass the current user to the view which is created by the ItemsDatatable controller. Debugging shows the index action running twice. The first time, user is set as expected. The second time, user is nil so it is never passed to ItemsDatatable. Why is that and how do I fix it? (If I unconditionally set user in the controller index action, it is passed.)

The second problem is more esoteric. If I am able to set @user in initialize, how do I pass that to as_json and onto the other ItemsDatatable actions? I suppose this is specific to jquery-datatables-rails and I might have to ferret out its logic to decide how to do that? Or is there a Rails way of doing that nicely?

FYI, this is the DataTables pattern from RailsCasts 340 that has been updated for DataTables 1.10.2.

Thanks for the help.

Home page buttons:

  <%= link_to 'Status-My Items',  items_path(select: "mine"), :class => 'btn btn-primary' %>
  <%= link_to 'Status-All Items', items_path(select: "all" ), :class => 'btn btn-primary' %>

ItemsController index action:

  def index
    user ||= params[:select] == "mine" ? current_user : nil
    respond_to do |format|
      format.html
      format.json { render json: ItemsDatatable.new(view_context, user) }
    end
  end

ItemsDatatable controller:

class ItemsDatatable < ApplicationController
  delegate :params, :h, :link_to, :edit_item_path, :new_item_path, :location, to: :@view

  def initialize(view, user)
    @view = view
    @user = user
  end

  def as_json(options = {})
    {
        draw: params[:draw].to_i,
        recordsTotal: Item.count,
        recordsFiltered: items.total_entries,
        data: data
    }
  end

  private

  def data
    todays_date = Date.today
    items.map do |item|
      [
          link_to(item.stock_number, edit_item_path(item))
      ]
    end
  end

  def items
    @items ||= fetch_items
  end

  def fetch_items
    items = Item.order("#{sort_column} #{sort_direction}")
    items = items.page(page).per_page(per_page)
    if params[:search][:value].present?
      items = items.where("stock_number ilike :search, search: "%#{params[:search][:value]}%")
    end
    items
  end

  def page
    params[:start].to_i/per_page + 1
  end

  def per_page
    params[:length].to_i > 0 ? params[:length].to_i : 10
  end

  def sort_column
    columns = %w[stock_number]
    columns[params[:order]['0'][:column].to_i]
  end

  def sort_direction
    params[:order]['0'][:dir] == "desc" ? "desc" : "asc"
  end
end

Answer 1

Looks to me like the answer to both questions is to use session storage:

The view:

  <%= link_to 'My Items',  items_path(my_view: current_user.id),
              class: 'btn btn-primary' %>
  <%= link_to 'All Items', items_path(my_view: "all"),
              class: 'btn btn-primary' %>

The controller:

session[:my_view] ||= params[:my_view]

Where used:

unless @view.session[:my_view] == "all"
  user = User.find(@view.session[:my_view]).name
  items = items.where("clshadow = \'#{user}\'")
end
@view.session[:my_view] = nil