# Tricky helper question

**URL:** <https://www.ruby-forum.com/t/tricky-helper-question/123140>\
**Category:** Rails\
**Created:** [December 14, 2007, 11:17am UTC](https://www.ruby-forum.com/t/tricky-helper-question/123140 "2007-12-14T11:17:36Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![silvertab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/22d042/32.png) [@silvertab](https://www.ruby-forum.com/u/silvertab)\
**Post date:** [December 14, 2007, 11:17am UTC](https://www.ruby-forum.com/t/tricky-helper-question/123140/1 "2007-12-14T11:17:36Z")

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I am trying to code a helper that will print a list of threaded forums,  
as options of a select field…a forum has a parent\_id (which is another  
forum’s id) or 0, meaning it is a “root level” forum…

For example, the result will look like:

Forum 1  
–Sub forum 1  
–Sub forum 2  
----Sub Sub Forum 1  
–Sub forum 3  
Forum 2  
–Sub forum 2a  
…

(picture this in a select menu)

There can be an unlimited amount of nested forums…my first thought was  
to use a recursive function, however, since an helper will only “print”  
what it returns (and should only return 1 thing) it’s a bit tricky… I  
don’t really see an easier way to this, but anyway here’s what I have so  
far:

* * *

def print\_child\_forums(master)  
#get the forum’s childs…  
childs = Forum.find(:all, :conditions =\> [“parent\_id = ?”,  
master.id], :order =\> ‘name ASC’)

```
if childs.size > 0 #forum has subforums
  #Here, I need to print this forum before going deeper!
  for child in childs
    print_child_forums(child)
  end

else
    #forum has no child, print it...
    "<option value=\"#{master.id}\">#{master.name}</option>"
end

```

## end

The problem obviously is that when a forum has child, it is never  
printed! since the only “return point” of the function occurs when the  
forum has no child… from what I understand, I can’t output any html in  
the helper function, except with it’s return value… and I can’t really  
use string concatenation since the function is being called multiple  
times (recursivity)…

my idea basically(using pseudo code) was quite simple:

print\_childs(master):  
if master has childs  
print master  
for each child:  
print\_childs(child) (recursivity)  
end for  
else (master has no child)  
print master  
end if master has childs  
end print\_childs

But this is turning out to be trickier than I thought… Note that I  
might be going at it all wrong, it’s 5am+ and I’m trying to get this  
done before going to bed…and somehow, I doubt I am thinking clearly  
LOL…

Any suggestions would be appreciated!

---

<div class="post-metadata">

**Author:** ![silvertab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/22d042/32.png) [@silvertab](https://www.ruby-forum.com/u/silvertab)\
**Post date:** [December 14, 2007, 11:36am UTC](https://www.ruby-forum.com/t/tricky-helper-question/123140/2 "2007-12-14T11:36:38Z")

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use partials instead  
partials can be recursive and can take arguments by :locals or  
:collection

---

<div class="post-metadata">

**Author:** ![silvertab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/22d042/32.png) [@silvertab](https://www.ruby-forum.com/u/silvertab)\
**Post date:** [December 14, 2007, 11:57am UTC](https://www.ruby-forum.com/t/tricky-helper-question/123140/3 "2007-12-14T11:57:14Z")

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Awesome! Got it to work by using a “recursive” partial 🙂

Thanks a lot!

Thorsten M. wrote:

> use partials instead  
> partials can be recursive and can take arguments by :locals or  
> :collection