链接和参数

Question

我正在尝试使一系列链接正常工作。有些应该是可切换的，有些则不是。

基本上在重新加载页面时，我的 params 哈希已经有两个不应该有的键，我看不到它们被添加到哪里。

我的链接：

<ul class="all filter__group">
  <li><%= link_to "View all", coasters_path(page: 1), remote: true %></li>
</ul>

<ul class="types filter__group">
  <%= content_tag(:li, class: ("active" if params[:type] == "steel")) do %>
    <%= link_to "Steel", coasters_path(type_parameters("steel", page: 1)), remote: true %>
  <% end %>
  <%= content_tag(:li, class: ("active" if params[:type] == "wood")) do %>
    <%= link_to "Wood", coasters_path(type_parameters("wood", page: 1)), remote: true %>
  <% end %>
  <%= content_tag(:li, class: ("active" if params[:type] == "powered")) do %>
    <%= link_to "Powered", coasters_path(type_parameters("powered", page: 1)), remote: true %>
  <% end %>
</ul>

<ul class="letters filter__group">
  <%= content_tag(:li, class: ("active" if params[:letters] == "#")) do %>
    <%= link_to "#", coasters_path(letter_parameters("#", page: 1)), remote: true %>
  <% end %>
  <%= content_tag(:li, class: ("active" if params[:letters] == "a-e")) do %>
    <%= link_to "A-E", coasters_path(letter_parameters("a-e", page: 1)), remote: true %>
  <% end %>
  <%= content_tag(:li, class: ("active" if params[:letters] == "f-j")) do %>
    <%= link_to "F-J", coasters_path(letter_parameters("f-j", page: 1)), remote: true %>
  <% end %>
  <%= content_tag(:li, class: ("active" if params[:letters] == "k-o")) do %>
    <%= link_to "K-O", coasters_path(letter_parameters("k-o", page: 1)), remote: true %>
  <% end %>
  <%= content_tag(:li, class: ("active" if params[:letters] == "p-t")) do %>
    <%= link_to "P-T", coasters_path(letter_parameters("p-t", page: 1)), remote: true %>
  <% end %>
  <%= content_tag(:li, class: ("active" if params[:letters] == "u-z")) do %>
    <%= link_to "U-Z", coasters_path(letter_parameters("u-z", page: 1)), remote: true %>
  <% end %>
</ul>
<%= debug params %>

辅助方法：

  # Add the type parameter to URL if not already there and remove if they are
  def type_parameters(type, options = {})
    parameters = {}
    if params[:type] == type
      # Get exisiting params
      parameters = params
      # Remove type
      parameters.delete(:type)
      # Merge any parameters passed in via options
      parameters.merge!(options)
    else
      # Get exisiting params
      parameters = params
      #Add type to new parameters variable
      parameters.merge!(type: type)
      # Merge any parameters passed in via options
      parameters.merge!(options)
    end
    parameters
  end

  # Add the letters parameter to URL if not already there and remove if they are
  def letter_parameters(letters, options = {})
    parameters = {}
    if params[:letters] == letters
      # Get exisiting params
      parameters = params
      # Remove letters
      parameters.delete(:letters)
      # Merge any parameters passed in via options
      parameters.merge!(options)
    else
      # Get exisiting params
      parameters = params
      #Add letters to new parameters variable
      parameters.merge!(letters: letters)
      # Merge any parameters passed in via options
      parameters.merge!(options)
    end
    parameters
  end

在页面重新加载时，这是当前的参数哈希：

--- !ruby/hash:ActiveSupport::HashWithIndifferentAccess
action: index
controller: coasters
type: powered
page: 1
letters: u-z

关于我哪里出错了有什么想法吗？

Answer 1

您正在从帮助程序中覆盖 params 哈希：当您使用 merge! 时，您正在覆盖原始的 params 哈希。

这应该可行：

# Add the letters parameter to URL if not already there and remove if they are
  def letter_parameters(letters, options = {})
    parameters = params.dup

    if params[:letters] == letters
      # Remove letters
      parameters.delete(:letters)
    else
      # Add letters to new parameters variable
      parameters.merge!(letters: letters)
    end

    # Merge any parameters passed in via options
    parameters.merge(options)
  end

注意使用dup 来创建参数哈希的新副本