In the Sinatra ruby framework, I have a route like this:
get '/portfolio/:item' do
haml params[:item].to_sym
end
This works great if the template that exists (e.g., if I hit /portfolio/website, and I have a template called /views/website.haml), but if I try a URL that doesn't have a template, like example.com/portfolio/notemplate, I get this error:
Errno::ENOENT at /portfolio/notemplate
No such file or directory - /.../views/notemplate.haml
How can I test and catch whether the template exists? I can't find an "if template exists" method in the Sinatra documentation.
Not sure if there is a Sinatra specific way to do it, but you could always catch the Errno::ENOENT exception, like so:
get '/portfolio/:item' do
begin
haml params[:item].to_sym
rescue Errno::ENOENT
haml :default
end
end
The first answer is not a good one because if a file does not exist a symbol is created anyway. And since symbols are not garbage collected you're easily leaking memory. Just think of a ddos attack against nonexisitng files that create symbols all the time. Instead use this route here (taken from one of my projects routing css files):
# sass style sheet generation
get '/css/:file.css' do
halt 404 unless File.exist?("views/#{params[:file]}.scss")
time = File.stat("views/#{params[:file]}.scss").ctime
last_modified(time)
scss params[:file].intern
end
Related
I have this code:
puts require './item'
puts $"
class Light < Item
#code
end
Item class in item.rb:
require './v3d'
require './ray'
class Item
attr_accessor :pos
def initialize(pos)
#pos = pos
end
def check(pos, dir)
return nil
end
def normal(ray)
return nil
end
end
that when I run my program prints this output:
false
enumerator.so
thread.rb
rational.so
complex.so
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/enc/encdb.so
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/enc/trans/transdb.so
/usr/lib/ruby/2.3.0/unicode_normalize.rb
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/rbconfig.rb
/usr/lib/ruby/2.3.0/rubygems/compatibility.rb
/usr/lib/ruby/2.3.0/rubygems/defaults.rb
/usr/lib/ruby/2.3.0/rubygems/deprecate.rb
/usr/lib/ruby/2.3.0/rubygems/errors.rb
/usr/lib/ruby/2.3.0/rubygems/version.rb
/usr/lib/ruby/2.3.0/rubygems/requirement.rb
/usr/lib/ruby/2.3.0/rubygems/platform.rb
/usr/lib/ruby/2.3.0/rubygems/basic_specification.rb
/usr/lib/ruby/2.3.0/rubygems/stub_specification.rb
/usr/lib/ruby/2.3.0/rubygems/util/list.rb
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/stringio.so
/usr/lib/ruby/2.3.0/rubygems/specification.rb
/usr/lib/ruby/2.3.0/rubygems/exceptions.rb
/usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb
/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_gem.rb
/usr/lib/ruby/2.3.0/monitor.rb
/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb
/usr/lib/ruby/2.3.0/rubygems.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/version.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/core_ext/name_error.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/levenshtein.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/jaro_winkler.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkable.rb
/usr/lib/ruby/2.3.0/delegate.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/name_error_checkers/class_name_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/name_error_checkers/variable_name_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/name_error_checkers.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/method_name_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/null_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/formatter.rb
/usr/lib/ruby/vendor_ruby/did_you_mean.rb
/home/<user>/Documents/ruby/ray/write_ppm.rb
/home/<user>/Documents/ruby/ray/v3d.rb
/home/<user>/Documents/ruby/ray/pixel.rb
/home/<user>/Documents/ruby/ray/image.rb
/home/<user>/Documents/ruby/ray/material.rb
then throws:
/home/<user>/Documents/ruby/ray/light.rb:4:in `<top (required)>': uninitialized constant Item (NameError)
When require './item' is called, there is no error AND it returns false. From my understanding of how require works, it seems that the program incorrectly thinks it does not need to load item.rb. Why does this happen and how can I fix it?
Edit: expanded on some code
As a generic answer, not related to op, but because I had a similar issue and was pointed here by search engines.
Basically require 'http' returned false while gem was not loaded.
I figured out that there is a http.rb file inside load path and it is being loaded instead of the standard gem. So double check there are no conflicting file names of ruby files under library load path and the gem name.
I solved the problem by totally rewriting my require statements for every file. What I think the problem was, was this:
item.rb contained require './ray'
ray.rb contained require './light'
light.rb contained require './item' and class Light < Item
While loading item.rb, the interpreter saw it needed to also load ray.rb and therefore light.rb. When it reached the require './item' inside light.rb, it returned false because it was in the process of loading that file. However, since it was not yet finished loading, it did not show up in $". The interpreter then needed access to the definition of the Item class to finish loading light.rb, but because it needed to finish loading light.rb to load item.rb, the interpreter thew a NameError.
I think you may want require_relative instead.
http://ruby-doc.org/core-2.4.0/Kernel.html#method-i-require_relative
vs
http://ruby-doc.org/core-2.4.0/Kernel.html#method-i-require
You are correct in saying that if require 'my_lib' returns false, then 'my_lib' has already been loaded. However this is different from saying that a MyLib class is defined. Does your item.rb define an Item class?
Also, it may be possible that Item is defined somewhere else in the namespace hierarchy. e.g. if your item.rb is in some_gem/item.rb, and you're calling require from some_gem/, it will load successfully, but the name of the class might be SomeGem::Item. In this case you wouldn't be able to access it directly from the root namespace.
Last thing I can think of is that the item.rb file is changing under, or otherwise has some very dynamic pieces that are confusing the interpreter.
I would think that the issue is one of these before thinking that require is somehow messing up.
I have a Sinatra app and I have some helpers and they have their folder (helpers) in which I have website_helpers.rb and so on. I want to move some of this helpers in their own folder inside the helpers folder: to have helpers/subhelpers, bacause the files I want to put in the subhelpers folder are different from the others and it makes sense to have a different folder for them.
I tried adding this to my config.ru
Dir.glob('./helpers/subhelpers/*.rb').each { |file| require file }
And then in the controller I have:
helpers MyHelperFromSubHelpers
but I get an error uninitialized constant (NameError).
Any ideas how to fix this so that to have a clear structure?
TBH, it sounds like you're overdoing it, there's always Rails if you want to go in for a more Java like every-namespace-must-be-a-directory layout. Aside from that, usually, helpers in separate files are placed in the Sinatra namespace - see http://www.sinatrarb.com/extensions.html#extending-the-request-context-with-sinatrahelpers
Personally, I put them in:
project-root/
lib/
sinatra/
name-of-extension.rb
Mainly because if the extension is really useful, I'll end up wanting to use it in another project, and this is the standard layout for a Sinatra gem, which makes it easy to extract it into one and with barely any change in the calling code.
Dir.glob will only return the file name and not the full path with each match, so you need to add the path:
Dir.glob('./helpers/subhelpers/*.rb').each do |file|
require File.expand_path File.join( File.dirname(__FILE__), "./helpers/subhelpers/", file)
end
will probably fix it.
I am writing a helper and I need to get a rendered file as String.
I see that the method that I need exists in the middleman's library: http://rubydoc.info/github/middleman/middleman/Middleman/CoreExtensions/Rendering/InstanceMethods#render_individual_file-instance_method
How do I call this function from my helper class?
I tried:
require "middleman-core/lib/middleman-core/core_extensions/rendering.rb"
...
puts Middleman::CoreExtensions::Rendering::InstanceMethods.render_individual_file(filepath)
But it does not seem to find the file, any idea?
I'm not sure 3.0 beta is quite ready for primetime.
That said, it does sound like the partial method is what you're looking for.
Unless I'm missing something, the Middleman method seems like an overly-complex solution. For one of my sites I wanted to load entire text files into my templates, so I wrote this helper:
# Shortcut for loading raw text files. Obviously assumes that given file is in a valid format.
# #return [String] File contents
def load_textfile(filename)
File.read filename.to_s
end
Also, you should clarify if you are intending to use this within a template, or within Ruby code. It's not clear to me based on your question.
Here is an example of how one would use above helper:
Currently of note, Middleman is in the process of transitioning to version 4, and the conventions for loading helpers will change. The most straightforward way to define a helper is within a helper block in your config.rb file, as follows:
helpers do
# Define helper functions here to make them available in templates
end
I use Slim for templating. It really is the best. In slim you would appply helper as thus:
= load_textfile 'path'
p You can embed helper output in your page with interpolation, too: #{load_textfile 'path'}
How can I access ruby instance variable from within coffeescript template?
In sinatra documentation it's said that templates are evaluated within same scope as rout that invoke that template.
So, I have following sinatra app:
server.rb:
require "sinatra"
require "coffee-script"
get '/app.js' do
#str = "Hello"
coffee :app
end
and in views/app.coffe file I would like to use #strvariable. Is it possible? If so, how can I access #str variable?
It could be possible only if you'll process coffee source file with something like erb. So if you'd use rails assets pipeline you can just append .erb to file extension and the file will be processed with erb before sending it to coffee I think in sinatra you'll have to wrap up something similar yourself.
The idea will be close to this one - http://www.sinatrarb.com/intro#Textile%20Templates
P.S: accessing variables from different layers of application is bad idea anyway.
EDIT
You have amultistage template compilation process in RAILS driven by a gem called sprockets. You start with a file for example called /app/views/foo/show.js.coffee.erb
class <%= #magic %>
doSomthing: ->
console.log "hello"
In your controller you add the instance variable
#magic = "Crazy"
Rails first processes the erb file and generates
class Crazy
doSomething: ->
console.log "hello"
Secondly it processes the coffeescript file to generate
var Crazy;
Crazy = (function() {
function Crazy() {}
Crazy.prototype.doSomething = function() {
return console.log("hello");
};
return Crazy;
})();
That is why it is called the asset pipeline. More conventionally you could call it
a compilation pipeline. If you know what you are doing you might be able to get sprockets running with Sinatra. However your life would be easier if you just used Rails 3.1 from
the start.
I wrote this for Rails: https://github.com/ludicast/ice
but it can be easily adapted for Sinatra.
It lets you use Eco and CoffeeKup templates inside a Rails application, with the ruby models exposed to Coffeescript.
Nate
I really don’t need the overhead of Rails for my very small project, so I’m trying to achieve this just using just plain Ruby and HAML.
I want to include another HAML file inside my HAML template. But I haven’t found a good—or really usable—way of doing this.
For example, I have these two HAML files:
documents.haml
%html
%body
= include(menu.haml) body
%article …
menu.haml
%ul
%li
%a whatever …
Include is obviously not the way to go here. But it does a nice job describing what I’m trying to achieve in this example.
I totally recommend the Tilt gem for these things. It provides a standard interface for rendering many different template langages with the same API, lets you set custom scope and locals, lets you use yield, and is robust and fast. Sinatra is using it for templates.
Example:
require 'haml'
require 'tilt'
template = Tilt.new('path/to/file.haml')
# => #<Tilt::HAMLTemplate #file="path/to/file.haml" ...>
layout = Tilt.new('path/to/layout.haml')
output = layout.render { template.render }
This lets you yield inside the layout to get the rendered template, just like Rails. As for partials, David already described a simple and nice way to go.
But actually, if what you're writing is going to be served over HTTP, i suggest you take a look at Sinatra, which already provides templating, and has the simplest request routing you could imagine.
I've done this before, just for a quick-and-dirty template producer. The easiest way is to just render the HAML inside the parent object:
%p some haml that's interesting
= Haml::Engine.new('%p this is a test').render
%p some more template
You'll more than likely want to build some methods to make this easier--a couple of helper methods. Maybe you write one called render_file that takes a filename as an argument. That method might look something like:
def render_file(filename)
contents = File.read(filename)
Haml::Engine.new(contents).render
end
Then, your template would look more like:
%p some template
= render_file('some_filename.haml')
%p more template
Note, you will probably need to pass self to the original Haml::Engine render so that it knows how to find your render_file method.
I've had great success just using the instructions posted by David Richards in a concatenated way, without variables, like this:
= Haml::Engine.new(File.read('/Volumes/Project/file_to_include.haml')).render
There's obviously a more elegant way. But for someone who just wants to include one or two files, this should work nicely. It's a drawback that all base files using these includes have to be recompiled after some changes to the latter. It might be worthwile to just use php include if the environment allows that.
def render_file(filename)
contents = File.read('views/'+filename)
Haml::Engine.new(contents).render
end
(Adding this semi-redundant answer to show how one might incorporate the techniques from other answers.)
Include something like this in your setup code to monkey-patch the Haml library.
module Haml::Helpers
def render_haml(filename)
contents = File.read(Rails.root.join("app", "assets", "templates", filename))
Haml::Engine.new(contents).render
end
end
Then in your Haml file
.foo
= render_haml('partial.haml')
.bar
Obviously this is a Rails-ish example (because I wanted to use HAML in my asset pipeline instead of as views)... You will want to replace Rails.root.join(...) with a way to find filename in your project's templates or partials directory.