How to prevent printing variables in view helper?

Question

I have an array, which is loaded from a database. It is in the following format:

["aaa:bbb", "ccc:ddd"]

And need to build an HTML definition list from the array:

<dl>
  <dt>aa</dt>
    <dd>bb</dd>
  <dt>cc</dt>
    <dd>dd</dd>
</dl>

Looks easy, isn't it?

I wanted to create a helper, which would go through the array, split the items on the :'s, and enclose them in tags:

<%= build_def_list(array) %>

However, I have encountered a problem. Namely, when I call a Rails helper from a view, all of its content goes to the output. That is, when I declare a variable within the body of a function and assign a value to it, the variable instantly goes to the output. Is there a way to suppress the printing of everything inside the body of a function?

UPD

Seriously, how to make this with helper?..

<dl>
    <% deflist.each do |item| %>
          <dt><%= item.split(':').at(0) %>:</dt>
            <dd><%= item.split(':').at(1) %></dd>
    <% end %>
</dl>

What is the rule that extracts `"aa"` and `"bb"` from `"aaa:bbb"`, and so on? — sawa, Dec 25 '13 at 16:24

vee · Answer 1 · 2013-12-25T16:51:04.477

1

Try this for your helper:

def build_def_list(array) 
  content_tag :dl do 
    array.map { |e| e.split(':') }.collect do |dt, dd| 
      content_tag :dt, dt
      content_tag :dd, dd
    end
  end 
end

Then in your view call <%= build_def_list(array) %>

Addition: (To filter what to print)

Thanks to @Arup who reminded me the additional check:

How it would prevent printing all?

To print only specific items, you can filter your input array first deleting any elements you need to remove then use the resultant array to build the content_tags as:

def build_def_list(array) 
 reject_keys = ['ccc'] 
 array = array.map { |e| e.split(':') }.reject { |e| reject_keys.include? e[0] }

 content_tag :dl do 
    array.collect do |dt, dd| 
      content_tag :dt, dt
      content_tag :dd, dd
    end
  end 
end

This will first split the elements of the array by : and delete all the elements if they are found in reject_keys array. The result is then used to build the content_tags.

edited Dec 25 '13 at 16:51

answered Dec 25 '13 at 16:28

vee

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How it would prevent printing all? – Arup Rakshit Dec 25 '13 at 16:30
@ArupRakshit, thanks for that. I didn't see that initially. Updated my answer to include the filtering. – vee Dec 25 '13 at 16:41
Good attempt!! Thank you very much :) – Arup Rakshit Dec 25 '13 at 16:42
This code prints empty dl – br. Dec 25 '13 at 16:49
@br., sorry there was a missing brace before `reject` call. That should have thrown an error. Please try this again. – vee Dec 25 '13 at 16:51
already fixed, but nothing changed – br. Dec 25 '13 at 17:07
Please post your input array and the reject array. – vee Dec 25 '13 at 17:08
i don't need to reject items, i need build definition list from array. but in fact i need to make custom output. But i can't use variables and cycles, because they printing out. – br. Dec 25 '13 at 17:14

How to prevent printing variables in view helper?

1 Answers1