Merge string and variable as argument?

Question

I want to pass the string 'header__button' and the response from method classify(f) as the argument class to link_to.

I tried

<%= link_to f, '/dashboard', class: 'header__button' classify(f) %>

but Ruby won't allow it. How can it be done?

Stefan · Accepted Answer · 2015-07-15T14:46:09.023

3

You can simply pass an array:

<%= link_to f, '/dashboard', class: ['header__button', classify(f)] %>

The documentation for tag and content_tag contains an example showing this usage (link_to calls content_tag to construct the <a> tag).

edited Jul 15 '15 at 14:46

answered Jul 15 '15 at 14:34

Stefan

This is the most elegant solution for OP's special case. (i.e. concatenating CSS classes in a Rails tag helper) – Daniel Rikowski Jul 15 '15 at 14:39
1

It actually is a documented feature: http://apidock.com/rails/ActionView/Helpers/TagHelper/tag / http://apidock.com/rails/ActionView/Helpers/TagHelper/content_tag – Daniel Rikowski Jul 15 '15 at 14:42

score 1 · Answer 2 · answered Jul 15 '15 at 14:12

1

Try concatenating the string and method:

<%= link_to f, '/dashboard', class: 'header__button ' + classify(f) %>

answered Jul 15 '15 at 14:12

Wes Foster

score 0 · Answer 3 · edited Jul 15 '15 at 14:31

0

Try interpolation using "#{}" as follows:

<%= link_to f, '/dashboard', class: "header__button #{classify(f)}" %>

Note that you need to be using double quotes "#{}".

edited Jul 15 '15 at 14:31

potashin

answered Jul 15 '15 at 14:12

vee

1

_Maybe I've missed something_, but it seems to be a valid answer. Downvoter, care to elaborate? – potashin Jul 15 '15 at 14:27
@Himmators please be more specific – Stefan Jul 15 '15 at 14:29

score 0 · Answer 4 · answered Jul 15 '15 at 14:14

0

You can also concatenate with <<:

<%= link_to f, '/dashboard', class: 'header__button ' << classify(f) %>

answered Jul 15 '15 at 14:14

potashin

score 0 · Answer 5 · answered Jul 15 '15 at 14:14

0

Will do the trick

<%= link_to f, '/dashboard', class: "header__button #{classify(f)}" %>

answered Jul 15 '15 at 14:14

Nermin

My version didn't work for the OP, not sure yours did :) – vee Jul 15 '15 at 14:26

5 Answers5