I have a custom yaml file that needs to use an ENV variable.
YAML.load_file('config/databases.yml')
Need to access the PASSWORD variable from the ENV variable like the below from the yaml file
TEST:
PASSWORD: ENV["TEST_DB_PW"]
This is not a RAILS app.
How do I do this? <% ENV["TEST_DB_PW"] %> works on RAILS but does not work if it is a simple ruby script.
require 'yaml'
class Databases
def initialize
if File.exist?('config/databases.yml')
#databases=YAML.load_file('config/databases.yml')
else
# You screwed up...
end
end
end
def print_data
#databases['TEST']['PASSWORD']
end
print_data needs resolving to the ENV parameter referenced in the YAML file.
<% ENV["TEST_DB_PW"] %> works on RAILS but does not work if it is a simple ruby script.
<% ... %> is an ERB tag. In order to use it, you have to parse the file accordingly.
Assuming you have a file config/database.yml:
TEST:
PASSWORD: <%= ENV["TEST_DB_PW"] %>
You can load it via:
require 'yaml'
require 'erb'
ENV["TEST_DB_PW"] = "secret"
YAML.load(ERB.new(File.read('config/database.yml')).result)
#=> {"TEST"=>{"PASSWORD"=>"secret"}}
This works for me and was confirmed by #halfelf
eval(#databases['TEST']['PASSWORD'])
if you want to assign it to a variable then
password = eval("#{#databases['TEST']['PASSWORD']}")
Related
I frequently use Sinatra for smallish projects. It's pretty good for what I need but I miss the ability to mark strings as HTML safe, and then ERB knowing when to escape or not escape accordingly.
I'd really like it if I could rip out the patches that Rails makes to Erubi (around here) and then apply those patches to Erubi myself so that tilt can just use the monkey-patched Erubi and everyone lives happily ever after. However, after digging around in the source, it's not clear to me how I could actually accomplish that.
I also tried to find some way to get an interface into ActionView like the render method, but I couldn't even find where that was defined.
How can I use ActionView outside of Rails, ideally by using ActionView's monkey-patches to Erubi, or if that won't work, how else can I use ActionView to go from template string to rendered string outside Rails?
Specifically, I'd like to be able to do the following:
def some_wrapper_func(unescaped_html)
"<div>#{h unescaped_html}</div>".html_safe
end
# test1.erb
hello world <%= "<script>alert('hi');</script>" %> <%= some_wrapper_func("<span>foobar</span>") %>
#=> hello world <script>alert('hi');</script> <div><span>foobar</span></div>
What you need here is ActiveSupport. I'm not sure if it is overkill or not, but you can do this:
#app.rb:
require 'sinatra'
require 'active_support/all'
get '/' do
erb :index
end
And in a view:
#views/index.erb
Hello, world!
<%= "<script>alert('Hello!')</script>".html_safe %>
Mind that requre 'active_support' will load nothing and requre 'active_support' will load all modules. You can specify what modules do need as described
in Active Support Core Extensions.
If the only goal is to enable auto-escaping, there is no need for ActionView at all. It can be done like this (mind the <%== %> tag):
#app.rb
require 'sinatra'
require 'erubis'
set :erb, :escape_html => true
get '/' do
erb :index
end
#View
<%= "<script>alert('Hello, and it will not produce alert!')</script>" %>
<%== "<script>alert('Hello and it will!')</script>" %>
We will try to get ActionView up and running with Sinatra (or any Ruby program):
require 'sinatra'
require 'action_view'
get '/' do
av_render :index
end
def av_render view
paths = ActionView::PathSet.new(["views"])
lookup_context = ActionView::LookupContext.new(paths)
renderer = ActionView::Renderer.new(lookup_context)
view_context = ActionView::Base.new(renderer)
renderer.render(view_context, template: view)
end
And in the view we use html_safe:
<%= "<script>alert('Hello, and it will not produce alert!')</script>" %>
<%= "<script>alert('Hello and it will!')</script>".html_safe %>
Wrapper functions also work with this approach. The only problem here is a custom-render method, but it can be avoided.
If you'd like to avoid ActionView entirely and just use Tilt+Erubi, you can actually create for yourself a SafeString class and have Erubi use it for compilation.
Erubi takes some important options, specifically:
- escape: If this is true, then <%= %> will escape by default, otherwise only <%== %> will escape by default
- bufval: Internally, erubi uses what is basically an accumulator to build up your template. This is the value that it will initialize that accumulator to. It is important that it has a <<(str) method to concat new pieces on, and a to_s method to get the return value out.
- escapefunc: The function that Erubi will use for escaping. It's important to override this, because we'll want to escape anything that isn't a SafeString but let SafeStrings pass through unchanged.
So, first let's define this SafeString class:
# main.rb
require 'tilt'
require 'erubi'
class SafeString
def initialize(str = '')
#str = str
end
def <<(str)
if str.is_a? String
return (#str << str)
elsif str.is_a? SafeString
#str = #str << str
return self
else
throw "Can't concat"
end
end
def to_s
#str
end
def self.escape(val)
if val.is_a? SafeString
return val.to_s
else
return Erubi.h(val.to_s)
end
end
module Helpers
def raw(content)
SafeString.new(content)
end
end
end
Then, we'll need to include the raw helper we defined and to test it on an ERB file:
include SafeString::Helpers
puts Tilt::ErubiTemplate.new("somefile.erb", bufval: 'SafeString.new', escapefunc: 'SafeString.escape', escape: true).render
# somefile.erb
<%= "<script>alert('Hello, and it will not produce alert!')</script>" %>
<%= raw("<script>alert('Hello and it will!')</script>") %>
And this will give us the output we desire!
# stdout
<script>alert('Hello, and it will not produce alert!')</script>
<script>alert('Hello and it will!')</script>
To improve this, instead of this minimal SafeString class, you could use ActiveSupport::SafeBuffer.
I don't have much experience with Ruby all I wan't to do is render a value that I declare in an .rb file in an .erb file.
In my .rb file I have this:
def abc()
begin
"aaaaa"
end
end
In my .erb file I have this:
Hello <% abc %>
When I run the app I only see:
Hello
But I expect to see:
Hello aaaa
Anybody can give me a hand, I don't really know ruby at all. Also I have no idea if this is ruby or ruby on rails so sorry if the tag below is wrong.
In Sinatra, register your method as a helper in .rb file:
helpers do
def abc
"aaaaa"
end
end
Omit parentheses if your methods don't need arguments. Also, begin/end block isn't necessary here.
You can call your helper in .erb template:
<%= abc %>
Don't forget = in the opening tag.
http://sinatrarb.com/intro.html section 'Helpers'.
It's unclear what you want to achieve. But If you just want some text in your erb you can do something like this:
erb :myerb, locals: {text: "aaaaa", saved: false}
myerb.erb
<% if saved %>
Hello <%= text %>
<% endif %>
This would also work for functions.
First of all, you need to be aware that a defined method inherently includes the functionality of a begin/end block so you don´t need to put them again. Assuming you are using sinatra, here is what I think you need:
my.rb
require 'sinatra'
def abc
"aaaa"
end
get '/' do
erb :my, locals: {variable: abc}
end
my.erb
<html>
<body>
<p>
Hello <%= variable %>
</p>
</body>
</html>
Run ruby my.rb and then open http://localhost:4567/
I'm using the gem "redcarpet". And I have a markdown file. I want to be able to render it with some ruby variables. Something like this:
# my_file.md
###Something
fdafdsfdsfds
---
<% for n in my_numbers do %>
<%= n %>
<% end %>
What's the proper way to do something like this? How can I pass and render a ruby
variable?
You can use the erb library which is included in ruby, but you have to require it:
require 'erb'
require 'redcarpet'
input = File.read "./file.md"
markdown = Redcarpet::Markdown.new(Redcarpet::Render::HTML, autolink: true, tables: true)
output = markdown.render ERB.new(input).result(binding)
File.open("output.html", "w") { |f| f.write output }
You can customize the markdown renderer by referencing the redcarpet readme
I'm working on a Sinatra app and want to write my own form helpers. In my erb file I want to use the rails 2.3 style syntax and pass a block to a form_helper method:
<% form_helper 'action' do |f| %>
<%= f.label 'name' %>
<%= f.field 'name' %>
<%= f.button 'name' %>
<% end %>
Then in my simplified form helper I can create a FormBuilder class and yield the methods to the erb block like so:
module ViewHelpers
class FormBuilder
def label(name)
name
end
def field(name)
name
end
def button(name)
name
end
end
def form_helper(action)
form = FormBuilder.new
yield(form)
end
end
What I don't understand is how to output the surrounding <form></form> tags. Is there a way to append text on only the first and last <%= f.___ %> tags?
Rails has had to use some tricks in order to get block helpers to work as wanted, and they changed moving from Rails 2 to Rails 3 (see the blogposts Simplifying Rails Block Helpers and Block Helpers in Rails 3 for more info).
The form_for helper in Rails 2.3 works by directly writing to the output buffer from the method, using the Rails concat method. In order to do something similar in Sinatra, you’ll need to find a way of writing to the output from your helper in the same way.
Erb works by creating Ruby code that builds up the output in a variable. It also allows you to set the name of this variable, by default it is _erbout (or _buf in Erubis). If you change this to be an instance variable rather than a local variable (i.e. provide a variable name that starts with #) you can access it from helpers. (Rails uses the name #output_buffer).
Sinatra uses Tilt for rendering templates, and Tilt provides an :outvar option for setting the variable name in Erb or Erubis templates.
Here’s an example of how this would work:
# set the name of the output variable
set :erb, :outvar => '#output_buffer'
helpers do
def form_helper
# use the new name to write directly to the output buffer
#output_buffer << "<form>\n"
# yield to the block (this is a simplified example, you'll want
# to yield your FormBuilder object here)
yield
# after the block has returned, write any closing text
#output_buffer << "</form>\n"
end
end
With this (fairly simple) example, an Erb template like this:
<% form_helper do %>
... call other methods here
<% end %>
results in the generated HTML:
<form>
... call other methods here
</form>
What would the erb template look like for a ruby enumerator? The answer will be a erb template.
require "erb"
# build data class
class Foo < Array
def build
b = binding
# create and run templates, filling member data variables
ERB.new(File.read('test2.erb')).result b
end
end
# setup template data
bar = Foo.new([1,2,3])
puts bar.build
I would like some way of accessing the 1,2,3 items in the erb template.
Focus on Ruby 1.9.3 compatibility.
Note: the Class is an extension of Array, and I want to access the elements of this array in its erb template.
Ok, it was as simple as reaching into the self reference.
<% self.each{|element| %> <%= element %> <% } %>