為什么在初始化外觀類時在Rails控制器中出現名稱錯誤？

Question

我正在創建一個簡單的Rails應用程序，該應用程序使用Open Weather Map API，並返回各種天氣參數。 我的API調用是在服務類中處理的，我正在嘗試遵循外觀模式並在PORO中處理參數數據。 我已經在下面的代碼。 我收到一個NameError. undefined local variable or method NameError. undefined local variable or method city'`知道我要去哪里了嗎？

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
  TOKEN = Rails.application.credentials.openweather_key

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

  def city
    @city = params[:q]
  end

  def forecast
    if @city.nil?
      @forecast = {}
    else
      @forecast = OpenWeatherApi.new(@city, TOKEN).my_location_forecast
    end
  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

Forecast_controller.rb

class ForecastsController < ApplicationController
  def current_weather
    @forecasts_facade = ForecastsFacade.new(city, forecast, temperature, weather_code, description, wind, humidity)
  end
end

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

Answer 1

從您的代碼中，我可以看到在current_weather.html.erb頁面上。 你寫：

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

這里ForecastsFacade是一個類。 forecast是一種實例方法。 因此，在調用函數時不會調用initialized 。

嘗試使用ajax請求，並在@forecasts_facade中使用js.erb來創建局部文件，這將有助於您實現功能。