Question

我正在sinatra建立一个库，使用postresql作为数据库和'googlebooks'宝石来查找我想要的信息。

这是我在main.rb中的代码

get '/list' do
  @books = GoogleBooks.search(params[:title])
  erb :list
end

get '/info/:isbn' do
  #this is to get the info from my database if there is any

   if book = Book.find_by(isbn: params[:isbn])
     @book_title = book.title
     @book_authors = book.author
     @book_year = book.year
     @book_page_count = book.page_count
     @book_id = book.id
     @book_isbn = book.isbn
  else
     #use the gem to look for the data

    text = GoogleBooks.search(params[:isbn])
    @book_title = text.title
    @book_author = text.authors
    @book_year = text.published_date
    @book_cover = text.image_link(:zoom => 2)
    @book_page_count = text.page_count
    @book_notes = text.description
   #and then store it into the database

   book = Book.new
   book.title = @book_title
   book.authors = @book_authors
   book.publish_date = @book_year
   book.image_link = @book_cover
   book.page_count = @book_page_count
   book.description = @book_notes
   book.isbn = params[:isbn]
   book.save
   @book_id = book.id

  end

 erb :info
end

这是我的erb文件：list

 <div class='list_by_title'>
   <% @books.each do |text| %>
     <ul>
       <li class='list_by_title'>
         <a href="/info/<%= text.isbn_10 %>"><%= text.title %>  (Authour: <%= text.authors %>)</a>
       </li>

     </ul>
    <%end%>
 </div>

列表部分有效..我能够有一个包含标题列表的页面...问题是当我尝试从params isbn调用数据时，我总是有这个错误：

  NoMethodError at /info/0596554877
 undefined method `title' for #<GoogleBooks::Response:0x007ff07a430e28>

对于可能的解决方案有任何想法吗？

Answer 1

根据documentation，GoogleBooks::Response是一个枚举器。因此，您需要使用each对其进行迭代，并对从枚举器检索的各个对象调用title方法。

result = GoogleBooks.search(params[:isbn])
result.each do |text|
  @book_title = text.title
  ...
end

变量名text有关书籍的详细信息并不是一个好名字，您需要选择apt变量名称，很多次好的变量名称使调试更容易

使用googlebooks的未定义方法

1 个答案: