Using will_paginate with array routing issue - ruby

Question

My project is currently configured to only have one view, import.html, that allows the user to upload and view contents of a CSV file (after uploading).
Here is the controller class import method:
class UploadController < ApplicationController
require "CSV"
require 'will_paginate/array'
def import
return if params[:file] == nil
file = params[:file]
#table = []
rowi = 0
CSV.foreach(file.path) do |row|
if rowi == 0 #and headers (for later)
#headers = row
else
#table << row.join("~")
end
rowi = rowi + 1
end
#table = #table.paginate(page: params[:page], :per_page => 20)
session
end
end
Here is the view:
<h1>Upload#import</h1>
<h4>UPLOAD A CSV FILE:</h4>
<%= form_tag({:action => "import"}, multipart: true) do %>
<%= file_field_tag :file %>
<%= submit_tag( "Import" ) %>
<% end %>
<% if #headers and #table %>
<h1>RESULTS</h1>
<table>
<thead>
<tr>
<% #headers.each do |column| %>
<td><%= column %></td>
<% end %>
</tr>
</thead>
<tbody>
<% #table.each do |row| %>
<tr>
<% row.split("~").each do |cell| %>
<td><%= cell %></td>
<% end %>
</tr>
<% end %>
</tbody>
</table>
<%= will_paginate #table, inner_window: 1, outer_window: 0%>
<% end %>
Here are the routes:
Rails.application.routes.draw do
root 'upload#import'
post "/" => "upload#import"
end
When interacting with my table to go to a different page, my routes have no specified instruction for:
GET "/?page=(pagenumber)"
I don't know what to tell it to do in order for the correct page to show.
It just defaults to redirecting to the import_page which clears all the data that has been imported. How should I fix this?

Answer 1

In a nutshell, you'll likely want to use a singular resource for this.
So you'd need the following:
In routes.rb:
resource :uploader, only: [:show, :create]
(N.B. this is a different use case to the more commonly-seen resources plural.)
This will give you the following routes:
POST /upload uploads#create # create the new upload
GET /upload uploads#show # display the one and only upload resource
In your controller:
class UploadController < ApplicationController
require "csv"
require 'will_paginate/array'
def create
return if params[:file] == nil
file = params[:file]
#table = []
rowi = 0
CSV.foreach(file.path) do |row|
if rowi == 0 #and headers (for later)
#headers = row
else
#table << row.join("~")
end
rowi = rowi + 1
end
# save the file to the db
# redirect to upload_path
end
def show
# Find the relevant table
#table = Table.last.paginate(page: params[:page], :per_page => 20)
end
end
Then you'll want to rework the form in your view to use #table, something like:
...
<%= form_for #table, multipart: true) do %>
<%= f.file_field :file %>
<%= f.submit "Import" %>
<% end %>
...
This is a very basic summary of how your project should work. The crux of it is using the correct, separate actions to create and show the table.
You'll likely want to look at using strong params and other Rails conventions.
Finally, if it helps, have a look at a generated Rails controller (i.e. rails generate controller my_example_controller) - this will have the create and show actions pre-built, and you can look to merge your code into something similar.
Hope this helps - give me a shout if you've any questions.