How to make custom Helpers in Rails 3?

manpreet Best Answer 2 years ago

I'm fairly new to Rails, and I was confused as to how I could pass local variables outside the if...else statement. It looks like creating a method in the helper file is the conventional way to do this, but I wasn't sure how to do this.

So I'm trying to get the Author of a Mission. If the author of a mission doesn't exist, I want to use the author of its parent Syllabus (missions belong to syllabus). And then I want to print out the username of that author. I was able to do this when I was dealing with only one mission, like:

//controller
@mission = Mission.first
if !@mission.author.blank?
  @author = @mission.author
else
  @author = @mission.syllabus.author
end

//view
<%= @author.username %> 

but I wasn't sure how to do this when I was dealing with a foreach loop:

//controller
@mission = Mission.all

//view 
<% @mission.each do |mission| %>
..(where do I put the logic of finding author? I can't put it in my controller anymore and it won't pass the @author variable outside the if else statement if I put the logic here in the view)..
<%= @author.username %>
<% end %>

My futile attempt was to create a helper:

def author_getter(mission_id)
  @mission = Mission.find(params[:mission_id])
  if !@mission.author.blank? 
    @author = @mission.author 
    return @author
  else
    @author = @mission.syllabus.author  
    return @author
  end 
end

and putting the below inside the loop

<%= author_getter(mission) %>

However, this didn't work. What would be the best way to pass on a variable outside the if...else statement?

manpreet 2 years ago

def author_of(mission)
  mission.author.present?? mission.author : mission.syllabus.author
end

def author_of(mission)
  mission.author || mission.syllabus.author
end

<% @missions.each do |mission| %>
    <%= author_of(mission).username %>
<% end %>

<% @mission.each do |mission| %>
    <%= (mission.author || mission.syllabus.author).username %>
<% end %>

class Mission
  def real_author
    author || syllabus.author
  end
end

<% @missions.each do |mission| %>
    <%= mission.real_author.username %>
<% end %>