empty parameter submitted but .nil failed to detect it

rubyonrails-talk
1

hi guys

i have a form which has an element, "category id".

When i submit it with values, i can see param(:category) with a value (as i print out that value in the controller's method.

Anyway, when i submit my form without selecting any category, the method in the controller does not pick up on it. I tried using .nil? but it doesn't work.

This is my code:     def get_subcategories         if params[:category]          puts " I M in GET SUBCATEGORIES -" + params[:category] + '...'         @category = Category.find(params[:category])         @sub_categories = @category.sub_categories.all         else             puts "no given category id to retrieve the subcategory"         end     end

When i run the application and submit without a category value , i notice that params[:category] is still defined (hence printing out "I M in GET SUBCATEGORIES") when it should not be. I have even tried "params[:category].nil?"

Any ideas? In perl, i could test the variable for truth (IE if ($params->{'category'}) then ...

2

Would .blank? do what you want?

Colin

3

Colin’s right - I would code: if not params[:category].blank?

4

Hi friend,

U can try this,

if params[:catergory] != nil