Question

我在控制器操作中有很多实例变量，我试图将它们移到外观中，但是遇到了错误。我是Rails的新手，所以有点麻烦。

我的应用程序联系Open Weather API，并返回一些天气参数（温度，风，湿度等）。该API调用是在服务类中处理的，我正在尝试使用Facade模式，并在PORO中使用一些方法来组织返回的数据，然后将这些数据呈现在我的视图中。目前，我收到了NameError. undefined local variable or method 'temperature' for ForecastsController。我对此并不陌生，因此不胜感激！我的代码在下面。

app / services / open_weather_api.rb

class OpenWeatherApi
  include HTTParty
  base_uri "http://api.openweathermap.org"

  def initialize(city, appid)
    @options = { query: { q: city, APPID: appid } }
  end

  def my_location_forecast
    self.class.get("/data/2.5/weather", @options)
  end
end

app / facades / forecasts_facade.rb

class ForecastsFacade

  def initialize(temperature, weather_code, description, wind, humidity)
    @temperature = temperature
    @weather_code = weather_code
    @description = description
    @wind = wind
    @humidity = humidity
  end

  def temperature
    @temperature = @forecast.dig('main', 'temp').to_i - 273
  end

  def weather_code
    @weather_code = @forecast.dig('weather', 0, 'id').to_i
  end

  def description
    @description = @forecast.dig('weather', 0, 'description')
  end

  def wind
    @wind = @forecast.dig('wind', 'speed').to_i
  end

  def humidity
    @humidity = @forecast.dig('main', 'humidity')
  end
end

app / controllers / forecasts_controller.rb

class ForecastsController < ApplicationController

  TOKEN = Rails.application.credentials.openweather_key

  def current_weather
    @city = params[:q]
    if @city.nil?
      @forecast = {}
    else
      @forecast = OpenWeatherApi.new(@city, TOKEN).my_location_forecast
    end
    @forecasts_facade = ForecastsFacade.new(temperature, weather_code, description, wind, humidity)
  end
end

app / views / forecasts / current_weather.html.erb

<div class="page-wrapper">
  <h1 class="title">The weather in GIFs</h1>

  <div class="search">
    <%= form_tag(current_weather_forecasts_path, method: :get) do %>
      <%= text_field_tag :q, nil, placeholder: "Enter a city", class: "search-field" %>
      <%= button_tag type: 'submit', class: "search-button" do %>
        <i class="fas fa-search"></i>
      <% end %>
    <% end %>
  </div>

  <% if @forecasts_facade.forecast.dig('cod').to_i == 404 %>
    <p>Please use a valid city name!</p>
  <% elsif @forecasts_facade.forecast.dig('cod').to_i == 400 %>
    <p>Please type in a city name!</p>
  <% elsif @forecasts_facade.forecast == {} %>
  <% else %>
    <p class="weather-description"><%= "#{@forecasts_facade.city.capitalize}: #{@forecasts_facade.description}" %></p>
    <div class="gif-container"><%= image_tag(find_gif_url, class: "gif") %>
      <span class="temperature weather-attribute"><%= "#{@forecasts_facade.temperature}°C" %></span>
      <span class="wind weather-attribute"><%= "wind:#{(@forecasts_facade.wind * 3.6).to_i}km/h" %></span> <!-- converts to km/hr -->
      <span class="humidity weather-attribute"><%= "humidity:#{@forecasts_facade.humidity}%" %></span>
    </div>
  <% end %>
</div>

app / helpers / forecasts_helper.rb

module ForecastsHelper
  GIFS = {
    thunder:
      {codes: [200, 201, 202, 210, 211, 212, 221, 230, 231, 232],
       urls: %w(
          https://media.giphy.com/media/26uf5HjasTtxtNCqQ/giphy.gif
          https://media.giphy.com/media/vS09bj1KrXwje/giphy.gif
          https://media.giphy.com/media/l41YsrmiyeNZtmecw/giphy.gif
)},
    light_rain:
      {codes: [300, 301, 302, 310, 311, 312, 313, 314, 321, 500, 501, 520, 521],
       urls: %w(
          https://media.giphy.com/media/xT9GEz2CeU9uaI2KZi/giphy.gif
          https://media.giphy.com/media/l0Expn6D0D3g9NExq/giphy.gif
          https://media.giphy.com/media/14d8cRr25KPxbG/giphy.gif
)},

  def find_gif_url
    GIFS.each do |key, value|
      if value[:codes].include? @weather_code
        return value[:urls].sample
      end
    end
  end
end

Answer 1

我相信您希望您的控制器看起来更像：

class ForecastsController < ApplicationController

  TOKEN = Rails.application.credentials.openweather_key

  def current_weather
    @city = params[:q]
    if @city.nil?
      @forecast = {}
    else
      @forecast = OpenWeatherApi.new(@city, TOKEN).my_location_forecast
    end
    @forecasts_facade = ForecastsFacade.new(@forecast)
  end
end

然后，您的ForecastsFacade更像：

class ForecastsFacade

  attr_accessor *%w(
    forecast
  ).freeze

  def initialize(forecast)
    @forecast = forecast
  end

  def temperature
    @temperature = forecast.dig('main', 'temp').to_i - 273
  end

  def weather_code
    @weather_code = forecast.dig('weather', 0, 'id').to_i
  end

  def description
    @description = forecast.dig('weather', 0, 'description')
  end

  def wind
    @wind = forecast.dig('wind', 'speed').to_i
  end

  def humidity
    @humidity = forecast.dig('main', 'humidity')
  end

  def invalid_city?
    forecast.dig('cod').to_i == 404 
  end

  def missing_city?
    forecast.dig('cod').to_i == 400
  end

end

然后，在您看来，做类似这样的事情似乎很奇怪：

@forecasts_facade.forecast.dig('cod').to_i == 404

要点是要在view中隐藏此详细信息。因此，也许更像是：

<div class="page-wrapper">
  <h1 class="title">The weather in GIFs</h1>

  <div class="search">
    <%= form_tag(current_weather_forecasts_path, method: :get) do %>
      <%= text_field_tag :q, nil, placeholder: "Enter a city", class: "search-field" %>
      <%= button_tag type: 'submit', class: "search-button" do %>
        <i class="fas fa-search"></i>
      <% end %>
    <% end %>
  </div>

  <% if @forecasts_facade.invalid_city? %>
    <p>Please use a valid city name!</p>
  <% elsif @forecasts_facade.missing_city? %>
    <p>Please type in a city name!</p>
  <% elsif @forecasts_facade.forecast.blank? %>
  <% else %>
    <p class="weather-description"><%= "#{@forecasts_facade.city.capitalize}: #{@forecasts_facade.description}" %></p>
    <div class="gif-container"><%= image_tag(find_gif_url, class: "gif") %>
      <span class="temperature weather-attribute"><%= "#{@forecasts_facade.temperature}°C" %></span>
      <span class="wind weather-attribute"><%= "wind:#{(@forecasts_facade.wind * 3.6).to_i}km/h" %></span> <!-- converts to km/hr -->
      <span class="humidity weather-attribute"><%= "humidity:#{@forecasts_facade.humidity}%" %></span>
    </div>
  <% end %>
</div>

您似乎没有使用该elsif @forecasts_facade.forecast.blank?分支。不知道这是怎么回事。

尝试将一些代码转移到外观时为什么会出现NameError？

1 个答案: