ruby-on-rails-3 - DBにクエリを実行せずにRansackオブジェクトを作成する

Question

search_form_forに渡されるRansack::Searchオブジェクトを作成できるようにしたいのですが、検索オブジェクトの最初の作成でデータベースにクエリが実行されます。

データベースを呼び出さずに、検索するRansack::Searchオプションを含む最初の空白のフォームを表示したいと思います。

どうやってやるの ？

ありがとう、

よろしく

Answer 1

Arel relations (ie. queries) are lazily-executed on first reference to the results, so you should find that you can create a search object and pass it to the form, without it calling the db, so long as you don't reference the .result method anywhere.

e.g.

// in your controller
my_query = MyModelClass.where{ id.gt(0) }
@q = my_query.search( params[:q] )

// in your view
search_form_for( @q, (...other options...) )

Any of these will trigger the db query to be actually performed:

- @q.results.each do |result| 
- for result in @q.results
- @q.results.count
- @q.results.to_a
- @q.results.size
// ....etc

But so long as you only use the search object for your form, it should not get executed.

Of course, if you're testing this from the console, make sure that you put ;nil at the end of the line, otherwise the console will print the last thing evaluated, which will cause the query to be run!