Why doesn't my recursive method from helper return every value?

Question

I want to display a tree of categories driven by a gem family tree.

I would like to use a helper element that will recursively traverse the tree and return categories one by one, at the moment without html tags or content.

module CategoriesHelper def display_tree(category) if category.has_children? category.children.each do |sub_category| display_tree(sub_category) puts(sub_category.name) # to check if it goes here end end category.name end end 

The category argument is one of the root categories.

What should he return?

• On the web page: It only displays the Sport Beauty Automobile root level category
• In console: Men Indoor Women Children Water sport Garage

If you get them, then recursion works, but it doesn’t. Why does it return only the first iteration?

I would also like to get them in the following order:

 root/child/child-of-child 

but if I want to return category.name , it should be in the last position.

Could you give me your comments?

PS: I just found out (when adding tags) that during my searches I used the word "recursion", but it does not exist, even if many people use it in stackOveflow; o)> "recursion", but still I'm stuck

** EDIT **

Now I use this code:

  module CategoriesHelper def display_tree(category) tree = "<div class =\"nested_category\">#{category.name}" if category.has_children? category.children.each do |sub_category| tree += "#{display_tree(sub_category)}" end end tree += "</div>" end end 

which gives me:

  <div class ="nested_category">Sport <div class ="nested_category">Men</div> <div class ="nested_category">Women <div class ="nested_category">Indoor</div> </div> <div class ="nested_category">Children</div> <div class ="nested_category">Water sport</div> </div> <div class ="nested_category">Beauty</div> <div class ="nested_category">Automobile <div class ="nested_category">Garage</div> </div> 

But this html is not interpreted, and the same code is displayed on the displayed web page. I mean i see

I probably missed something ... maybe knowledge oO

thanks

Answer 1

The mothod you use will return only one value (actually a cubic call to category.name) About the console, you get the interference that you have inside the loop (this is not the return value of the method).

Try this and let me know if something else is unclear:

 module CategoriesHelper def display_tree(category) tree = category.name if category.has_children? category.children.each do |sub_category| tree += "/#{display_tree(sub_category)}" end end tree end end 

Answer 2

  module CategoriesHelper def display_tree(category) tree = "<div class =\"nested_category\">#{category.name}" if category.has_children? category.children.each do |sub_category| tree += "#{display_tree(sub_category)}" end end tree += "</div>" tree.html_safe #That was missing to interprete the html returned... end end 

I am responsible for my last editing question. I had to add this line:

 tree.html_safe 

to interpret the string.

thanks