How can I render via CoffeeScript in Ruby on Rails 4 - javascript

I was trying to solve this problem for a while with no result.
I've wanted to pass variables and load a render into a div using CoffeeScript in rails 4.
(I'm using SpreeCommerce platform).
view:
<%= link_to taxonomy.name,root_path+'t/'+tid, {class: "uno", remote: true} %>
controller:
respond_to do |format|
format.html
format.js # menu.js.coffee.erb
end
menu.js.erb.coffee:
$('div#productos').html("<%= escape_javascript(render :partial => /shared/products) %>")
I'd like to load the page '_products.erb.html' and the partial processes the variables that I give it. As soon as I know, view and controller are ok, the problem is in menu.js.erb.coffee
Any help will be apreciated!
ADDITIONAL:
I've modified the extension to .js.coffee.erb. When I try to run the app, it shows me:
"undefined method `render' for #<#:0xa70317c>"
I tryied using <%= raw escape_javascript( render :partial =>... almost always "render" method give me problems.
NEW INFO:
I added gem 'coffee-script' to the Gemfile (then 'bundle install').
Now, when I click the link_to, it shows me into the HTML <%= escape_javascript(render :partial => /shared/products) %> as a text instead of loading the "partial"... any suggestion please?

I wrote a post about this after struggling through the same problem.
You need to:
Name it menu.js.coffee. Suffixing .erb causes it not to be evaluated as CoffeeScript.
Use raw to escape it.
I used these two on my website. Here's how it looks:
<%= raw render 'path/to/menu.js.coffee' %>
It still processes ERB within your CoffeeScript.

I would recommend changing it from menu.js.erb.coffee to menu.js.coffee.erb.
Rails will process the file extensions from right to left. Meaning right now, your file is treated first as coffeescript, then as ruby, and finally as javascript. It looks like you want to make the ruby substitutions first, then parse the coffeescript into javascript, so that would be menu.js.coffee.erb

First of all, you should change file name from menu.js.erb.coffee to menu.js.coffee.erb and you need configuration file as follow, which is a contribution by cervinka on coffee-rails issue #36
config/initializers/coffee_erb_handler.rb
ActionView::Template.register_template_handler 'coffee.erb', Coffee::Rails::TemplateHandler # without this there will be template not found error
class ActionView::PathResolver < ActionView::Resolver
EXTRACT_METHODS = %w{extract_handler_and_format_and_variant extract_handler_and_format} # name for rails 4.1 resp. 4.0
method_name = EXTRACT_METHODS.detect{|m| method_defined?(m) || private_method_defined?(m)}
raise 'unknown extract method name' if method_name.nil?
old_method_name = "old_#{method_name}"
alias_method old_method_name, method_name
define_method(method_name) do |path, default_formats|
self.send(old_method_name, path.gsub(/\.js\.coffee\.erb$/, '.js.coffee'), default_formats)
end
end

Related

Ruby on Rails - modifying part of embedded Ruby in .js.erb

I'm working on a single-page site and have gotten the ajax loading of templates to insert into the content part of the site working. However, I'm having trouble doing this with multiple templates, using a parameter.
I have 5 templates, shared/blog, shared/projects, etc.
In my controller, I'm doing an AJAX call to 'replace'
pages = ['blog', 'projects', 'resume', 'gallery', 'contact']
def replace
#content = params[:content]
if not pages.include? content
content = 'blog'
end
respond_to do |format|
format.js
end
end
In replace.js.erb, I have this code:
$(".content_inner").html("<%= j render(:partial => 'shared/blog') %>");
I have kept it just saying 'shared/blog' because it works for loading the blog if I keep the embedded Ruby static like that. However, I can't figure out how to replace the 'blog' part of 'shared/blog' in here to whatever is in the #content variable. I've tried things like #{content}, but to no avail.
(It does receive the content variable correctly, the issue is just with using it)
Any help would be appreciated!
Thanks.
String interpolation requires double quotes. You're after:
$(".content_inner").html("<%= j render("shared/#{#content}") %>");
A few notes:
The :partial => hasn't been necessary for years in Rails. Just use render <partial_name>.
Rails already comes with a place to store your shared partials: app/views/application. You should move your shared partials there, and then you can render them simply by using render(#content). This is important to how Rails works, because it allows you to override the partial in controller-specific view paths. For example, calling render("blog") will render app/views/<controller_name>/blog.js.erb if it exists, and then fallback to app/views/application/blog.js.erb otherwise.

Rails test JS view from controller spec

I've got a controller action that responds with a js response. This js response actually renders another partial. I'd like a controller test in case the partial or js file ever has an error.
controller:
class ZonesController < ApplicationController
def library_zones
end
end
library_zones.coffee:
$("#zoneSelectionPlaceholder").html("<%= j(render 'library_zones') %>")
_library_zones.html.haml (notice I call the model BadName, trying to get an error):
= collection_select(:zones, :zone_id, BadName.library_zones, :id, :description, {prompt: 'Zone to Add...'}, {id: 'zoneToAddSelection'})
routes.rb:
resources :zones do
collection do
get 'library_zones
end
end
spec:
RSpec.describe ZonesController, type: :controller do
describe 'library_zones' do
it 'renders library_zones.js template' do
xhr :get, :library_zones
expect(response).to render_template('library_zones')
expect(response.status).to eq(200)
end
end
end
All my specs are passing. I've tried introducing haml parse errors into the _library_zones.html.haml file as well as trying to introduce js errors into the librarys_zones.coffee file, but nothing seems to cause this test to fail.
RSpec 3.1.7
By default, controller specs do not render views unless you specifically enable it:
https://www.relishapp.com/rspec/rspec-rails/v/3-0/docs/controller-specs/render-views

Passing variable to Javascript doesn't work in Rails 4.2

I have just created a simple Rails 4.2 application to upload file to S3. I'm trying to follow this article https://devcenter.heroku.com/articles/direct-to-s3-image-uploads-in-rails#submitting-and-rendering-the-images and it looks like in javascript <%= #variable %> gets parsed as string.
I tried this.
This is what I have in /users/new
# GET /users/new
def new
#s3_direct_post = S3_BUCKET.presigned_post(key: "uploads/#{SecureRandom.uuid}/${filename}", success_action_status: 201, acl: :public_read)
#user = User.new
end
And this is what I tried in application.js
window.vaz = <%= #s3_direct_post.url %>;
but when I do console.log(window.vaz); I get "<%= #s3_direct_post.url %>" instead of the real value.
I tried gon as well but gon has a lot of issues with Rails 4.2
I verified that #s3_direct_post.url returns something in the console.
Add .erb extension to application.js file (application.js.erb). <%= => is erb syntax and you need to process it as erb file first so that <%= #s3_direct_post.url %> is evaluated as ruby code.
http://guides.rubyonrails.org/asset_pipeline.html#preprocessing

Include a Coffeescript file with ERB in a view

This is giving me a major headache...
So I have an app which requires a sidebar that lists various information to do with a user's player. One section of this sidebar is a friends list. Now, when Player A sends a friend request to Player B, the request should be automatically logged in B's sidebar, and I intend to use WebSockets to do this.
Here is my cp.js.coffe.erb file (there's only a few snippets of ERB at the moment; there will be loads more and I rather get this working first):
$ ->
$("#cp").accordion()
if `"WebSocket" in window`
socket = new WebSocket("ws://localhost:8080")
socket.onopen = =>
console.log("Connection Open")
init = {
sender: "cp"
action: "init"
user: <%= #user.id %>
token: <%= cookies["remember_token"] %>
}
socket.send(init.to_json)
socket.onerror = (e)=>
console.log(e)
socket.onclose = =>
console.log("Closed")
socket.onmessage = (m)=>
console.log("Recieved: #{m.data}")
msg = m.data.JSON.parse
switch msg.action
when "ret_init"
when "friend_udt"
refreshFriend()
refreshFriend() ->
html = "<%= j render 'layouts/friends' %>"
$('#friends').empty()
$('#friends').add(html)
Theoretically, the code itself works fine, the problem being that Rails doesn't let you use ERB in the assets pipeline, and so this file has to sit in app/views/layouts.the file cannot access the variables declared within a controller or use the render method (or most other ERB methods).
Here's the thing: I can't include said file in my application.html.erb file, and I looked into requesting the file with AJAX, but from my understanding that will immediately execute the Javascript once and once only, and I need the methods in this to be constantly available to update the sidebar.
Is there any way of including this file so that it works with the ERB and the CoffeScript so that it would be continuously avaliable to the page? Am I misunderstanding the whole AJAX requesting method?
Thanks #nzifnab for your help with the JS. Now my friends partial looks like this:
<ul id="friendlist">
<% if Relation.find_by(owner: #user.id, type: "freq") != nil %>
<% Relation.find_by(owner: #user.id, type: "freq").each do |r| %>
<li class="friend-request-cp"><%= link_to "/#{User.find(r.character).name}" %></li>
<% end %>
<% end %>
<% if Relation.find_by(owner: #user.id, type: "friend") != nil %>
<% Relation.find_by(owner: #user.id, type: "friend").each do |r| %>
<li class="friend-cp"><%= link_to "/#{User.find(r.character).name}" %></li>
<% end %>
<% end %>
</ul>
I need to apply two different styles to each item, hence why I'm using the ERB here. This works fine, as it's loaded when the page is first navigated to, but my code was supposed to re-render that partial every time a notification comes through of any new interactions. It would then repopulate the list using the data from the database again. Is there a more efficient way of doing this? Can I still do this with the hamlcoffeeassets gem you showed me?
Slight tangent ensues:
By the way, I'm using Ruby 2.0.0-p247 and Rails 4 on Windows 7. I felt the need to include that because of some major compatibility issues with gems that are much different from Ubuntu. I had to move from Ubuntu to Windows because updating from 13.04 to 13.10 broke everything Ruby Gem on that OS. I don't have tome to find a fix: I literally have only four days to get this app built.
You can kinda use erb in the asset pipeline, but you have to remember that it only gets rendered ONCE, EVER, and not once for every user and so even if there was an #user variable (which there won't be), it would never change. You can use erb in your coffee file for things like route paths and environment variables, but not for things like user-specific config and dynamic changes to the JS. It's bad practice anyway.
What you should really do is use a javascript library to read cookies instead of trying to do it with rails (This will give you access to some of the things you appear to be trying to do). And when you need more dynamic behavior you should render data-attributes or other values into the html DOM itself and use the javascript to read that.
Take a look at this cookie library: https://github.com/carhartl/jquery-cookie
There's many others to look at via a quick google search.
socket.onopen = =>
console.log("Connection Open")
init = {
sender: "cp"
action: "init"
user: $.cookie('user_id')
token: $.cookie('remember_token')
}
There are a couple of ways to render new markup for your view using JS. One way is to use js templates. I'm a big fan of the hamlcoffeeassets library here: https://github.com/netzpirat/haml_coffee_assets Although it uses haml for the view, and not ERB. There are ERB variants as well.
You would add some markup to app/assets/templates/friend.jst.hamlc like so:
%p This is my friend markup #{#friend.name}
And then you can render it from your JS like this:
$('#friends').append(JST['templates/friend'](friend: {name: 'Bob'}))
Which will append the markup from your template with the values you've passed interpolated in. In my example you'd end up with this markup inside your #friends container:
<p>This is my friend markup Bob</p>
Alternatively you can render the partial you want via rails into your JSON response as just a string, and then insert that into your document...
So your JS might look something like this:
socket.onmessage = (m)=>
console.log("Recieved: #{m.data}")
msg = m.data.JSON.parse
switch msg.action
when "ret_init"
when "friend_udt"
refreshFriend(msg.friendHTML)
refreshFriend(html) ->
$('#friends').html(html)
UPDATE
In reference to your ERB question... First of all your partial is incredibly inefficient making similar calls to the database four times every time you render it. haml_coffee_assets is for use with the haml markup language (which I prefer over ERB), if you want ERB then use eco instead: https://github.com/sstephenson/eco
If you want to render this in the JS, then you need to send this "friend relation" data as JSON through the notification data response, you do not have access to active record OR any controller methods or instance variables when rendering javascript partials - they don't hit back to the server, they only use what is accessible by your javascript at the time.
This should really go to app/assets/javascripts/cp.js.coffee.erb, you can use erb in the asset pipeline just fine (see here) Make sure you are spelling the coffee extension right, though!
Doing this, you should be able to call this via ajax without problems, the path would be /assets/cp.js.
try this gem: 'coffeebeans'
name your coffee file as "some_file.html.erb"
<%= coffeescript_tag_do %>
# your coffee script here ...
<% end %>
in another erb file:
<%= render file: '.../some_file' %>

Rails render JS partial printing code to page

I'm using AJAX in my Rails app to render a JS error message when needed. It was working initially, but now coming back to it some time later, it still shows the JS error message but for some reason it now also prints the entire JS file as HTML in the window. This is what's called in the controller:
respond_to do |format|
format.js { render :partial => 'error' }
end
My file named _error.js.erb contains some JS which isn't relevant as regardless of what it contains Rails prints it to the window still.
This is what the JS looks like outputted to the window: (I tried commenting out the JS to see if it made a difference)
You can try it with some modification :
respond_to do |format|
format.js
end
Inside the action and in the view action_name.js.erb write your js code ar if you want to put your erb then use escape_javascript.
Check the following link :
Why escape_javascript before rendering a partial?
I did it! In case there will be someone else wondering a few years later, there's the answer: you should put rendered value in a javascript_tag inside your html.erb. Like this:
javascript_tag render: 'error'
that will put what rendered between <script>...</script> tags and escape all unnecessary code.
Here's the documentation on it

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