How to include Ruby string in JavaScript

Question

I have the ruby code:

<%= "hello #{@namevar}" if condition %>

I can include ruby snippet in JS in the following way-

<script>
    var v1="<%= @user.name  %>"
</script>

But can't embed the previous code in JavaScript.

I have tried the following:

var v2="<%= \"hello #{@namevar}\" if condition %>";

But didn't work.

Thanx.

What do you want to do? Assign the string to a variable depending on a condition? — Tom Fenech
– Tom Fenech, Commented Mar 6, 2014 at 9:19
I want this <%= "hello #{@namevar}" if condition %> to get into a JS variable — Rajesh Paul
– Rajesh Paul, Commented Mar 6, 2014 at 9:19

Slicedpan · Accepted Answer · 2014-03-06 09:30:37Z

3

Your attempt is almost correct, you don't need to escape the double quotes inside the ruby code though:

var v2="<%= "Our funding ask is #{@startup.funding_ask_text}." if @startup.try(:funding_ask_text) %>";

answered Mar 6, 2014 at 9:30

Slicedpan

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1 Comment

Rajesh Paul Over a year ago

Thanx. this worked. I didn't event expect it to work according to conventions. Thanx.

Richard Peck · Accepted Answer · 2014-03-06 09:55:52Z

1

Asset Pipeline

You can't include ruby code in your asset pipeline

If you want to include "naked" ruby, you'll have to use .js.erb and put the file in your views directory. The reason for this is because the asset pipeline can be precompiled, which will render the Ruby code useless

Vars

If you want to use rails-based data in your JS, you'll have to first render the data in your views, and then call it from JS (like Bachan's answer)

You can use the Gon gem for this

answered Mar 6, 2014 at 9:55

Richard Peck

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3 Comments

Rajesh Paul Over a year ago

var v1="<%= @user.name %>" wasn't a problem at all. So what do u want to say?

Richard Peck Over a year ago

I don't want to "say" anything - I was trying to give you some idea as to how to include vars in your asset JS. Including naked ruby code in your asset pipeline is bad practice & will lead to problems in future

Rajesh Paul Over a year ago

Ok. thanx for the elaboration. +1

Bachan Smruty · Accepted Answer · 2014-03-06 09:22:17Z

0

In your layout add a hidden_field

<%= hidden_field_tag 'user_name', @user.name%>

And in script

var v1 = $('#user_name').val()

answered Mar 6, 2014 at 9:22

Bachan Smruty

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1 Comment

Rajesh Paul Over a year ago

This should be simple. But you r giving such a solution for which I need an extra dom element!!! This definitely is not the solution.

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