如何在Rails帮助器的内插ERB字符串中包含coffeescript变量？

Question

I would like to include this coffeescript variable ( chordCount ) in the ERB below, but when it runs it has an error because it is trying to interpret chordCount as a ruby variable. How can I use it in the ERB?

app/views/static_pages/add_chord.js.coffee (below) is reached via a remote: true link. It works perfectly with the one exception mentioned above (eg if I replace the variable with "4" then it works fine, but with the variable it throws an error).

chordCount = $('.chordSearchForm').find('.chordSearchFieldRow').length

# define the html for the row to add
rowToAdd = "<div class='row chordSearchFieldRow'>" +
    "<div class='large-8 small-12 columns'>" +
    '<%= collection_select :chords, :chord_#{chordCount}, Chord.order("name ASC"), :id, :name, {}, { :multiple => false, class: "chordSearchField", id: "chord_#{chordCount}_search_field" } %>' +
    "</div>" +
    "</div>"

Thanks!

Answer 1

Firstly, you don't want to be writing html like this. Use the tag helpers:

http://api.rubyonrails.org/classes/ActionView/Helpers/TagHelper.html#method-i-content_tag

Secondly, for storing variables for use in javascript, it's best to set it in a data attribute.

An example might look like this:

content_tag(:p, data: { chord_count: chordCount })

which would make it available in your js by

$("p").data("chord_count")

if your using jquery.