ruby: Create block for a string

Question

I have this object:

object.name

Sometimes name could be an array, sometimes it could be a string and sometimes an empty string. And so I assumed I could do something like this:

object.name do |name|
  name.is_a?(Array) ? name.join(' ') : name
end.presence

But this does not work, I can access name in the block but anything I do to it does not return.

What am I actually doing by passing name into a block like that? and how can I make this ruby lovely and work?

Thanks!

Why in your case does name have multiple possible types? If you want to accept multiple types to set the value, that will mean you will want a different solution than if it inherently can hold multiple types of data. — Neil Slater
– Neil Slater, Commented Feb 9, 2014 at 14:30
I can not control what name is and how it is formatted as this is built on top of not so good code. — bymannan
– bymannan, Commented Feb 9, 2014 at 14:38

north636 · Accepted Answer · 2014-02-09 14:30:29Z

3

A simple way to do this is using the splat operator:

name = [ *object.name ].join(' ')

If object.name is just a string, the code will essentially be doing:

name = [ 'some string' ].join(' ')

Which will just result in 'some string'. However, if object.name is an array of strings, you'll end up with:

name = [ 'first string', 'second string', 'third string' ].join(' ')

Which will result in 'first string second string third string'.

answered Feb 9, 2014 at 14:30

north636

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1 Comment

Another way to do this is with the Array() method: Array(object.name).join(' ')

sawa · Accepted Answer · 2014-02-09 14:41:29Z

1

Use a combination of tap and break.

object.name.tap do |name|
  break name.is_a?(Array) ? name.join(' ') : name
end.presence

answered Feb 9, 2014 at 14:41

sawa

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