Rails: Retrieve value from hash in array

Question

There's a good number of related questions but their answers haven't helped me. I have a method fetch_all_sections which populates an array with this line:

all_sections << {:id => section.id, :sortlabel => section.sortlabel, :title => section.title, :depth => depth}

In a loop in a view, I would like to easily access the values by their key, like this:

<% fetch_all_sections(@standard).each do |section| %>
  <%= section.id %>
<% end %>

This says no method id on section. section[:id] and #{section['id']} have similarly themed errors. I used a hash for ease of retrieval - should I use a different structure?

I'm hoping I don't need .map like section.map { |id| id[:id] } for every value.

EDIT: Here's the context. It's a little loopy (pun intended) but it does what's intended.

# Calls itself for each section recursively to fetch all possible children
def fetch_all_sections(standard, section = nil, depth = 0)
  all_sections = []

  if section.nil?
    rootsections = standard.sections.sorted
    if ! rootsections.nil?
      rootsections.each_with_index do |section, i|
        depth = section.sortlabel.split('.').length - 1
        all_sections.push(fetch_all_sections(standard, section, depth))
      end
    end
  else

    all_sections << {:id => section.id, :sortlabel => section.sortlabel, :title => section.title, :depth => depth}

    section.children.sorted.each do |section|
      all_sections | fetch_all_sections(standard, section)
    end
  end

  return all_sections
end

MrYoshiji · Accepted Answer · 2013-01-17 19:41:58Z

1

Try with the following:

<% fetch_all_sections(@standard).each do |section| %>
  <%= section['id'] %>
<% end %>

If not working, try debugging using these methods:

<% fetch_all_sections(@standard).each do |section| %>
  <%= section.inspect %>
  <%= section.class %>
<% end %>

As the Question author said, this fixed:

all_sections << fetch_all_sections(standard, section, depth).first

And tell us the output of the inspect

edited Jan 17, 2013 at 19:41

answered Jan 17, 2013 at 18:50

MrYoshiji

54.9k13 gold badges130 silver badges120 bronze badges

Sign up to request clarification or add additional context in comments.

8 Comments

Archonic Over a year ago

It indeed seems that I've made an array of arrays with 1 hash that has multiple key, value pairs. This works section[0][:id]. flatten apparently doesn't affect it.

MrYoshiji Over a year ago

Can you post the code of your fech_all_sections method please @Archonic?

Archonic Over a year ago

Perhaps since the method calls itself, the array initializer is being pushed.. to itself? Inception! But all_sections = [] if all_sections.nil? changed nothing.

MrYoshiji Over a year ago

fetch_all_sections returns an array and you push the result of fetch_all_sections into another Array. You have a bi-dimensionnal Array here, you need to flatten it after your push.

Archonic Over a year ago

flatten unfortunately doesn't remove sub-arrays if each element is by itself an array. [[1],[2],[3]].flatten #=> [[1],[2],[3]]

|

Collectives™ on Stack Overflow

Rails: Retrieve value from hash in array

1 Answer 1

8 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

8 Comments

Your Answer

Sign up or log in

Post as a guest

Related