ruby on rails 调用外部 api 并显示结果

Question

我正在尝试调用 API（喜欢 https://jsonplaceholder.typicode.com/）。这个想法很简单，单击按钮以显示 res，但我在实现它时遇到了麻烦。我下面的只是调用该函数的按钮，并希望在控制台中打印它。

错误：

enter code here No route matches [POST] "/dashboard/fetch_action"

路线

resources :dashboard do
 collection do
   get :fetch_action
 end
end

dashboard_controller.er

require 'faraday'

def index
end

def fetch_action
    response = Faraday.get 'https://jsonplaceholder.typicode.com/posts/1'
    puts response
    # return response 
end

index.html.erb

    <%= button_to "fetch action", fetch_action_dashboard_index_path, class: "btn btn-warning" %>

谢谢

编辑：

路线：

Rails.application.routes.draw do

  devise_for :users
  
  devise_scope :user do
    root to: 'devise/sessions#new'
  end

  get 'dashboard' => 'dashboard#index'
  get '/dashboard/fetch-action', to: 'dashboard#fetch_action', as: 'dashboard_fetch_action'
  get '/user' => 'dashboard#index', :as => :user_root

end

搜索路线

    new_user_session GET    /users/sign_in(.:format)                                                                 devise/sessions#new
             user_session POST   /users/sign_in(.:format)                                                                 devise/sessions#create
     destroy_user_session DELETE /users/sign_out(.:format)                                                                devise/sessions#destroy
        new_user_password GET    /users/password/new(.:format)                                                            devise/passwords#new
       edit_user_password GET    /users/password/edit(.:format)                                                           devise/passwords#edit
            user_password PATCH  /users/password(.:format)                                                                devise/passwords#update
                          PUT    /users/password(.:format)                                                                devise/passwords#update
                          POST   /users/password(.:format)                                                                devise/passwords#create
 cancel_user_registration GET    /users/cancel(.:format)                                                                  devise/registrations#cancel
    new_user_registration GET    /users/sign_up(.:format)                                                                 devise/registrations#new
   edit_user_registration GET    /users/edit(.:format)                                                                    devise/registrations#edit
        user_registration PATCH  /users(.:format)                                                                         devise/registrations#update
                          PUT    /users(.:format)                                                                         devise/registrations#update
                          DELETE /users(.:format)                                                                         devise/registrations#destroy
                          POST   /users(.:format)                                                                         devise/registrations#create
                     root GET    /                                                                                        devise/sessions#new
                dashboard GET    /dashboard(.:format)                                                                     dashboard#index
   dashboard_fetch_action GET    /dashboard/fetch-action(.:format)                                                        dashboard#fetch_action
                user_root GET    /user(.:format)                                                                          dashboard#index
       rails_service_blob GET    /rails/active_storage/blobs/:signed_id/*filename(.:format)                               active_storage/blobs#show
rails_blob_representation GET    /rails/active_storage/representations/:signed_blob_id/:variation_key/*filename(.:format) active_storage/representations#show
       rails_disk_service GET    /rails/active_storage/disk/:encoded_key/*filename(.:format)                              active_storage/disk#show
update_rails_disk_service PUT    /rails/active_storage/disk/:encoded_token(.:format)                                      active_storage/disk#update
     rails_direct_uploads POST   /rails/active_storage/direct_uploads(.:format)                                           active_storage/direct_uploads#create
           
                                                                                     

index.html.eb

<%= link_to "fetch action", dashboard_fetch_action_path, class: "btn btn-info" %>

<%= @response %>

fetch-action.html.erb

<%= @response %>

dashboard_controller

def index
end

def show
end

def fetch_action
    uri = URI('https://jsonplaceholder.typicode.com/posts/1')
    req = Net::HTTP.get(uri)
    @response = JSON.parse(req)
end

错误（当点击 link_to 重定向到仪表板/获取操作时出现以下错误）：

DashboardController#show is missing a template for this request format and variant. request.formats: ["text/html"] request.variant: [] NOTE! For XHR/Ajax or API requests, this action would normally respond with 204 No Content: an empty white screen. Since you're loading it in a web browser, we assume that you expected to actually render a template, not nothing, so we're showing an error to be extra-clear. If you expect 204 No Content, carry on. That's what you'll get from an XHR or API request. Give it a shot.

Answer 1

故障排除和设置路线

首先，在您的终端中，运行rake routes 以打印出您应用中的路线。在此处发布该输出。但是您需要检查该命令的输出，以检查您在按钮中使用的fetch_action_dashboard_index_path - 这是正确的路径吗？

我认为不是。还有一种更简单的方法来声明一条路线。您对路由中的资源声明所做的是为仪表板控制器的索引、显示、创建、更新和删除操作配置路由。您的 routes.rb 文件中的以下行将仅设置 fetch_action 路由并将其命名为“dashboard_fetch_action”

get '/dashboard/fetch-action', to: 'dashboard#fetch_action', as: 'dashboard_fetch_action'

创建指向该路线的链接

第二；使用 link_to 而不是 button_to 来确保您发出 GET 请求。您正在应用的 btn 类将把该链接设置为看起来像一个按钮，a 标记在语义上比 button 更正确（因为你想 GET）所以使用：

<%= link_to "fetch action", dashboard_fetch_action_path, class: "btn btn-warning" %>

渲染动作结果

最后确保您在app/views/dashboard/fetch_action.html.erb 中有一个文件，该文件会将 API 响应呈现为 HTML。此内容（或类似内容）将实现这一目标。

<%= @response =>

并且，在仪表板控制器中的 fetch_action 操作中。代替response = Faraday...，使用@response = Faraday...。这样response 对象就可以在视图 HTML 中被访问（这就是 @ 表示的意思）

def fetch_action
    @response = Faraday.get 'https://jsonplaceholder.typicode.com/posts/1'
end

Answer 2

您是否尝试将模板重命名为 fetch_action.html.erb？

据我所知，Rails 希望模板名称与动作名称相匹配，这可能是 fetch_action，因为 Ruby 方法不能包含破折号 -。破折号用于减法，这就是它在方法名称中无效的原因。