will_paginate switching page by persisting a search form

gistfile1.rb

#  We need to trigger click event for pagination links and search submit. Also, we need to post
#  to the entry point when searching, as it will avoid handling the search in 2 different places.
# 
#  The submit click event resets the page hidden field. The link event will get the page 
#  number, updates the page hidden field and submits the form.

# routes.rb
get 'will_paginate', to: 'will_paginate#index'
post 'will_paginate', to: 'will_paginate#index'

# will_paginate_controller.rb
def index
  page = params[:page] == "" ? nil : params[:page]
  
  # note that you should for params[:query] to avoid expensive queries
  @users = User.where("name LIKE ?", "%#{params[:query]}%")
               .paginate(page: page, per_page: 5)
end

# The form
<%= form_tag("/will_paginate", id: 'my_form', name: 'my_form') do %>
  <%= hidden_field_tag :page, params[:page], id: 'page' %>
  <%= label_tag(:query, 'Search for:') %>
  <%= text_field_tag(:query, params[:query]) %>
  <%= submit_tag("Find", id: 'find') %>
<% end %>

<%= render partial: 'table', locals: {uses: @users}

<%= will_paginate @users, id: 'pagination' %>

# the script
<script>
  $("#find").click(function() {
    // resets pagination
    $("#page").val("");
  });

  $("#pagination a").click(function() {
    // get all search form attributes
    var query = $('#query').val()

    // whe only want to post if the form has values
    if (query) {
      // gets the page attribute from the link we clicked
      var pos = this.href.search("page=");
      var page = this.href.substring(pos + 5, this.href.length);

      // updates the hidden input and submits the form
      $("#page").val(page);
      $('#my_form').submit();

      return false;
    }

    // else, let the GET request happen
    console.log('GET request');
    
  })
</script>