erb in coffee script with rails 3.1
I would like to use some erb in my .coffee
files, like the following example
myLatlng: new google.maps.LatLng(<%=@location.latitude %>, <%=@location.longitude %>)
I renamed my locations.js.coffee
to locations.erb.coffee
but 开发者_运维问答I still get the following error
Error compiling asset application.js:
ExecJS::ProgramError: Error: Parse error on line 4: Unexpected 'COMPARE'
(in /Users/denisjacquemin/Documents/code/projects/geolog/app/assets/javascripts/locations.erb.coffee)
Served asset /application.js - 500 Internal Server Error
If you want erb in the .coffee
files IN YOUR VIEW folder, leave your file named as yourfilename.js.coffee
, and Rails will still process the ERB, oddly enough.
To make it work in Heroku, move coffee-rails out of the assets group in your Gemfile.
You may have to rename your file to locations.coffee.erb so erb is processed before coffee :)
Stick to the asset pipeline when possible in Rails 4, instead of using a js.erb
view.
Pass variables to the Js using gon or some other technique discussed at: Ruby on Rails - Send JavaScript variable from controller to external Javascript asset file
With gon
:
app/views/layouts/application.html.erb:
<head>
<meta charset="utf-8"/>
<%= include_gon %>
app/controllers/application_controller.rb:
before_filter do
gon.latitude = 0.1
gon.longitude = 0.2
end
app/assets/javascripts/locations.js.coffee:
myLatlng: new google.maps.LatLng(gon.latitude, gon.longitude)
This method is faster because file is precompiled only once at startup, gets served by the server instead of through Rails, and on the same HTTP request as the rest of the Js.
In Rails 3.2.8, I didn't have to move my .coffee file to /app/views. I just added .erb to the filename and left it in /app/assets/javascripts. Ie. I changed
/app/assets/javascripts/user_answers.coffee.js to
/app/assets/javascripts/user_answers.coffee.js.erb
and then this worked:
# Note the level of indentation.
var x = 2;
<% Question.first(2).each do |eq| %>
alert('eq: ' + <%= eq.id %>)
<% end %>
(The indentation level has to match in CoffeeScript, not Ruby.) Enjoy your coffee embedded in rubies.
I agree with Ciro Centelli to leave the asset pipeline alone, especially if you are using Heroku. No doubt gon
is useful if you need to many assignments, but you can also do this without a gem. In your html include
<%= javascript_tag do %>
window.latitude = <%=@location.latitude %>
window.longitdue = <%= @location.longitude %>
<% end %>
and in your coffee file
myLatlng: new google.maps.LatLng(window.latitude, window.longitude)
You can often work around other needs in a similar fashion. For instance if you do not want the coffee script to trigger on an element with particular id, then in the html use erb to only add that id when you want it triggered.
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