我已經創建了三個類來表示書籍,人和BookLoans的關聯記錄之間具有一對多類。雖然我能夠通過BookLoans展示人與書的關聯,但我一直在播種我的數據庫。如何保存在Ruby on Rails的
我現在需要保存一本書的結帳。我打算通過圖書管理員來執行此操作。具體而言,在BooksController中創建貸款操作。雖然這在理論上對我來說很有意義,但我有一段可怕的時間來實現適當的語法。
我已經添加了從書籍的展示視圖中借閱圖書的功能。這個視圖現在包含一個表格,它使用賬簿管理員的貸款行爲來記錄貸款。
我已經添加了我認爲適合我的Book模型的方法。在theIV的幫助下,我已經在控制器中捕獲了適當的信息。不幸的是,當我在書籍展示視圖上按下貸款時,book_loan記錄沒有被記錄。
我錯過了什麼?
Book模型從BooksController中
def loan
@book.add_loan(params[:book_loan][:person_id])
redirect_to :action => 'book', :id => params[:id]
end
書顯示視圖
class Book < ActiveRecord::Base
has_many :book_loans
has_many :borrowers, :through => :book_loans, :source => :person
accepts_nested_attributes_for :book_loans, :allow_destroy => true
def loaned?
book_loans.exists?(:return_date => nil)
end
def current_borrower
if loaned?
book_loans.first(:order => "out_date desc").person
end
end
def add_loan (person_id)
book_loans.create(:book_id => id,
:person_id => person_id,
:out_date => Date.current)
end
end
貸款方法W /貸款形式
<p>
<b>Title:</b>
<%=h @book.title %>
</p>
<p>
<b>Isbn10:</b>
<%=h @book.isbn10 %>
</p>
<p>
Currently loaned to:
<%=h borrower_name(@book) %>
</p>
<% form_for(@book) do |x| %>
<p>
<%= x.label :loan_person_id %><br/>
<%= collection_select(:book_loan, :person_id,
Person.find(:all, :order => 'name ASC'), :id, :name) %>
<%= x.submit 'Loan', :action => 'loan' %>
</p>
<% end %>
BookLoan型號
class BookLoan < ActiveRecord::Base
belongs_to :book
belongs_to :person
end
角色模型
class Person < ActiveRecord::Base
has_many :book_loans
has_many :books, :through => :book_loans
end
開發日誌
Processing BooksController#update (for 127.0.0.1 at 2009-09-24 13:43:05) [PUT]
Parameters: {"commit"=>"Loan", "authenticity_token"=>"XskHLuco7Q7aoEnDfVIiYwVrMEh5uwidvJZdrMbYYWs=", "id"=>"1", "book_loan"=>{"person_id"=>"3"}}
[4;35;1mBook Columns (3.0ms)[0m [0mSHOW FIELDS FROM `books`[0m
[4;36;1mBook Load (4.0ms)[0m [0;1mSELECT * FROM `books` WHERE (`books`.`id` = 1) [0m
[4;35;1mSQL (0.0ms)[0m [0mBEGIN[0m
[4;36;1mBook Load (1.0ms)[0m [0;1mSELECT `books`.id FROM `books` WHERE (`books`.`title` = BINARY 'Dreaming in Code: Two Dozen Programmers, Three Years, 4,732 Bugs, and One Quest for Transcendent Software' AND `books`.id <> 1) LIMIT 1[0m
[4;35;1mSQL (1.0ms)[0m [0mCOMMIT[0m
Redirected to http://localhost:3000/books/1
Completed in 19ms (DB: 10) | 302 Found [http://localhost/books/1]
[4;36;1mSQL (0.0ms)[0m [0;1mSET NAMES 'utf8'[0m
[4;35;1mSQL (0.0ms)[0m [0mSET SQL_AUTO_IS_NULL=0[0m
什麼是創建視圖的最佳選擇。爲了簡單起見,我想用本書作爲跳板點,這就是爲什麼我想通過person_id。目前我正試圖在書籍編輯中添加一個額外的表單。 此外,感謝您的人,我會旋轉我的輪子一點。 – ahsteele 2009-09-24 18:35:24
您可以爲圖書貸款添加一個'fields_for'到您的圖書表單。您也可以查看'acceptersted_attributes_for' http://www.railsapi.com/doc/rails-v2.3.4/classes/ActiveRecord/NestedAttributes/ClassMethods.html – theIV 2009-09-24 18:47:42
對不起,擴大一點前面的評論。如果你爲你的圖書貸款添加一個'fields_for',你應該首先在你的控制器中建立一個圖書貸款 - '@ loan = @ book.book_loans.build'-然後在@loan – theIV 2009-09-24 18:49:14