Rails：如何从视图切换布尔字段？

Question

I have a boolean field called "saved" in my database. I want to toggle this field by clicking on a text link that changes from "Save" to "Unsave" depending on the situation, and updates my "Customer" table with 0 or 1. I imagine Javascript may be a way to go for this but I am not experienced enough (yet!) in Javascript to know how to code it.

I've rolled back the question to keep it shorter. Here is my exact code.

#employers controller
def save_toggle
  @matching = Matching.find(params[:id])
  if @matching.employer_stars == false
    @matching.employer_rejects = false # If saving a match, remove any existing rejection.
  end
  @matching.employer_stars = !@matching.employer_stars
  @matching.save
  render :partial => "save_unsave_buttons", :layout => false
end

#view home.html.erb
<%= render :partial => "save_unsave_buttons", :locals => {:matching => matching} %>

#partial _save_unsave_buttons.html.erb
<div id="save_buttons" class="buttonText"> #latter is just for CSS layout
  <% if @matching.employer_stars %>
    <%= link_to_remote "Unsave",
      :url => {:action => "save_toggle", :id => matching.id},
      :update => {:success => "save_buttons", :failure => "Error"} %>
  <% else %>
    <%= link_to_remote "Save",
      :url => {:action => "save_toggle", :id => matching.id},
      :update => {:success => "save_buttons", :failure => "Error"} %>
  <% end %>
</div>

The database is working but the toggle text isn't switching. To @nathanvda: I'm really sorry for being such a pain - I want to confirm your answer but I know if I do I'll just leave this for a while then come back to it and get frustrated again! Thanks man.

Answer 1

You have to define a controller-method, which sets your saved attribute. In your view you can then link to this method using link_to_remote .

That should get you started.

--Update: after updated question:

You should create a partial that renders your save/unsave button like this, call it "_save_unsave_buttons.html.erb" :

<div id="save_buttons">
  <% if matching.employer_stars %>
    <%= link_to_remote "Unsave",
       :url => {:action => "save_toggle", :id => matching.id},
       :update => {:success => "save_buttons", :failure => "Error"} %>
  <% else %>
    <%= link_to_remote "Save",
       :url => {:action => "save_toggle", :id => matching.id},
       :update => {:success => "save_buttons", :failure => "Error"} %>
  <% end %>
</div>

This partial will render you correct save-buttons, and upon update the containing div is updated/replaced by the result of your controller action.

From inside your main view, write

<%= render :partial => "save_unsave_buttons", :locals => {:matching => match } %>

where you want the buttons to be visible.

And inside your controller:

def save_toggle
  @matching = Matching.find(params[:id])
  @matching.employer_stars = !@matching.employer_stars
  @matching.save
  render :partial => "save_unsave_buttons", :locals => {:matching => @matching}, :layout => false
end

Good luck!

--Update again: so i presume you render a set of @matchings, i would change the naming between the collection and the item a bit, to prevent more confusion and accidental mistypings.

But actually this is pretty easy:

@matchings.each do |match|
  .. build your view here ..
  <%= render :partial => "save_unsave_buttons", :locals => {:matching => match}
end

and in your partial you can then use the correct matching everywhere.

Answer 2

Just a notice:

Your save_toggle method is not RESTful. The HTTP PUT verb should be implemented idempotent (See oa http://en.wikipedia.org/wiki/Idempotence#Examples ), which means it should always do the same thing no matter how often you execute it. In your example, executing the save_toggle method once does not give the same result as executing it twice.

A better practice would be to make two methods, eg:

def set_employer_stars
end

def unset_employer_stars
end

or whatever you want to call them. Then you can also use these two different methods in the link_to_remote methods (because you now use save_toggle in both "Unsave" and "Save").