rails linkedin gem：如何掃描所有用戶字段的空虛

Question

快速問題：我使用linkedin gem來提取用戶數據，但是如果用戶的LinkedIn配置文件中某個特定的數據字段爲空，我的應用會中斷。有沒有一種最佳的方式來掃描每個配置文件的所有數據字段的空白，並只拉取那些存在以防止破壞？

這裏是我的auth_controller ...我知道它不是乾的，需要重構。謝謝！

require 'linkedin' 

class AuthController < ApplicationController 

    def index 
    client = LinkedIn::Client.new(ENV['LINKEDIN_KEY'], ENV['LINKEDIN_SECRET']) 
    request_token = client.request_token(:oauth_callback => 
             "http://#{request.host_with_port}/callback") 
    session[:rtoken] = request_token.token 
    session[:rsecret] = request_token.secret 
    redirect_to client.request_token.authorize_url 
    end 

    def callback 
    client = LinkedIn::Client.new(ENV['LINKEDIN_KEY'], ENV['LINKEDIN_SECRET']) 
    if session[:atoken].nil? 
     pin = params[:oauth_verifier] 
     atoken, asecret = client.authorize_from_request(session[:rtoken], session[:rsecret], pin) 
     session[:atoken] = atoken 
     session[:asecret] = asecret 
    else 
     client.authorize_from_access(session[:atoken], session[:asecret]) 
    end 

     current_user = client.profile(:fields => %w(positions educations)) 
     @user = current_user 
     educations = current_user.educations.all 
     positions = current_user.positions.all 

     companies = current_user.positions.all.map{ |t| t.company } 

     @current_company = companies[0]['name'] 
     @past_company_one = companies[1]['name'] 
     @past_company_two = companies[2]['name'] 
     @past_company_three = companies[3]['name'] 

     @current_industry = companies[0]['industry'] 
    @past_industry_one = companies[1]['industry'] 
    @past_industry_two = companies[2]['industry'] 
    @past_industry_three = companies[3]['industry'] 

     @first_name = client.profile(:fields => ["first_name"]).first_name 
    @last_name = client.profile(:fields => ["last_name"]).last_name 
    @headline = client.profile(:fields => ["headline"]).headline 
     @picture = client.profile(:fields => ["picture-url"]).picture_url 

     @school_one_name = educations[0]['school-name'] 
     @school_one_degree = educations[0]['degree'] 
    @school_one_field = educations[0]['field-of-study'] 
    @school_one_start = educations[0]['start-date']['year'].to_s 
    @school_one_end = educations[0]['end-date']['year'].to_s 

    @school_two_name = educations[1]['school-name'] 
     @school_two_degree = educations[1]['degree'] 
    @school_two_field = educations[1]['field-of-study'] 
    @school_two_start = educations[1]['start-date']['year'].to_s 
    @school_two_end = educations[1]['end-date']['year'].to_s 

    @current_title = positions[0]['title'] 
    @past_title_one = positions[1]['title'] 
    @past_title_two = positions[2]['title'] 
    @past_title_three = positions[3]['title'] 

    @current_start_date = Date::MONTHNAMES[positions[0]['start-date']['month']] + " " + positions[0]['start-date']['year'].to_s 

    @past_start_date_one = Date::MONTHNAMES[positions[1]['start-date']['month']] + " " + positions[1]['start-date']['year'].to_s 
    @past_end_date_one = Date::MONTHNAMES[positions[1]['end-date']['month']] + " " + positions[1]['end-date']['year'].to_s 

    @past_start_date_two = Date::MONTHNAMES[positions[2]['start-date']['month']] + " " + positions[2]['start-date']['year'].to_s 
    @past_end_date_two = Date::MONTHNAMES[positions[2]['end-date']['month']] + " " + positions[2]['end-date']['year'].to_s 

    @past_start_date_three = Date::MONTHNAMES[positions[3]['start-date']['month']] + " " + positions[3]['start-date']['year'].to_s 
    @past_end_date_three = Date::MONTHNAMES[positions[3]['end-date']['month']] + " " + positions[3]['end-date']['year'].to_s 

    end 
end 

Answer 1

考慮當前的代碼可以在響應時任何意外的值突破並假設它發生在你上面callback方法，你可以考慮只採用quick'n'dirty異常處理代碼。

例如，通過簡單地包封在begin/end塊的潛在有問題的代碼，並使用rescue子句處理任何異常：

def callback 
    client = LinkedIn::Client.new(ENV['LINKEDIN_KEY'], ENV['LINKEDIN_SECRET']) 

    if session[:atoken].nil? 
    # ...code 
    else 
    #...code 
    end 

    # start handling exceptions here 
    begin 
    # ...potentially offending code here 
    current_user = client.profile(:fields => %w(positions educations)) 
    # ...more code 
    @past_end_date_three = Date::MONTHNAMES[positions[3]['end-date']['month']] + " " + positions[3]['end-date']['year'].to_s 
    rescue 
    # oops, something happened: 
    # ...your code to handle the exception here 
    end 

end