RoR ruby -- undefined method `model_name' for NilClass:Class -


i'm having trouble update on class.

this view:

    <div id = "list">         <%= form_for @list |form| %>         <%= render 'shared/error_messages', object: form.object %>         <div class="list_fields">          <%= form.text_field :name, placeholder:

and controller:

     def update          if @list.update_attributes(params[:list])             flash[:success] = "list updated"          else             render 'edit'          end          redirect_to @list     end

the routes are:

       resources :lists, only: [:create, :show, :destroy,:edit]

now problem keeps raising 

      "undefined method `model_name' nilclass:class"             in line 2  --->   <%= form_for @list |form| %>

and can't seem figure out why. in advance leo

you have load @list before update attributes.

def update   @list = list.find_by_id(params[:id])   if @list.update_attributes(params[:list])     flash[:success] = "list updated"   else     render 'edit'   end   redirect_to @list end

and way, problem see not caused update action edit action redirects view.

you have load @list in both actions. in edit action in order render view, in update action in order update appropriate object.


Comments

Post a Comment

Popular posts from this blog

Eclipse formatter for java ending braces -

i know if it's possible setup eclipse format braces using banner style. we're working code uses banner style formatting , keep consistent within team version control reasons. here's example of banner style formatting not familiar: public class foo { //------------------------ public static void main (string[] args) { boolean condition = true; try { if (condition) { system.out.println ("condition true"); } else system.out.println ("not condition"); } catch (exception ex) { // handle errors } } //------------------------ } update: name style ratliff. experiment java->code style->formatter preferences. "banner style" seems poor use of space given outline view , quick outline functionality.
Read more

ruby - Nesting modules inside of a Rails eninge gem -

what proper syntax nest child modules within parent module being isolate_namespace rails engine gem? # lib/myengine/engine.rb module myengine class engine < rails::engine isolate_namespace myengine # def ... end end for example. parent module myengine , child module blog. myengine share common domain, crud, taggable, searchable, etc, keep gem code dry , isolated main app (myapp), while inheriting isolated namespace , engine. are either of 2 approaches correct? refactor advice? # # lib/myengine/blog.rb module myengine module blog # def ... end end # b # lib/myengine/blog.rb module myengine class engine < rails::engine isolate_namespace myengine module blog # def ... end end end option a. correct, should lib/my_engine/blog.rb . can read more ruby & rails naming conventions here . further, if want put more modules or classes under blog namespace put them in folder lib/my_engine/blog , nest them under myengine::bl...
Read more

php - Why I am getting the Error "Commands out of sync; you can't run this command now" -

the documentation of error mentioned in title says if commands out of sync; can't run command now in client code, calling client functions in wrong order. this can happen, example, if using mysql_use_result() , try execute new query before have called mysql_free_result(). can happen if try execute 2 queries return data without calling mysql_use_result() or mysql_store_result() in between. from here: http://dev.mysql.com/doc/refman/5.0/en/commands-out-of-sync.html but in first query not fetching data mysql database, inserting. , in second query getting data database. here code $connection = mysqli_connect("localhost","username","password","tbl_msgs"); if(mysqli_connect_errno($connection)) { die("failed connect mysql: " . mysqli_connect_error()); } $query = "insert users (total_comments, total_views) values ({$total_comments}, {$total_views});"; $query .= "insert msgs (no...
Read more