I was working on a project and was having issues with therubyracer and libv8 often, so i decided to remove them. It seemed to be the only thing that used them as a dependency was less-rails which I wanted to remove anyways.
My main question is what are they for and do I need them in the average application and if so why?
There are a few things for which a Rails app might use a Javascript Runtime:
1) The Rails Asset Pipeline requires a Javascript Runtime in order to perform Javascript compression.
2) Certain Rails ActionView Helpers like javascript_include_tag require a Javascript Runtime in order to execute Javascript functions.
Not every Rails application use those features, hence the reason that therubyracer gem is initially commented out in your Gemfile; Furthermore note that you could alternatively use NodeJS as your Javascript runtime.
For details, see:
http://guides.rubyonrails.org/asset_pipeline.html#javascript-compression
http://www.rubydoc.info/docs/rails/ActionView/Helpers/JavaScriptHelper
http://www.rubydoc.info/docs/rails/ActionView%2FHelpers%2FAssetTagHelper%3Ajavascript_include_tag
Proper "Rails" way to perform javascript on specific pages
rubyracer provides following features:
1. We can write your ruby codes inside js codes.
2. We can invoke the js functions from ruby codes.
3. Manipulation of javscript objects & the passing them to javascript functions.
Those are the few basic benefits of using rubyracer gem.
Please read complete details here
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I want to use googlecharts in my rails App, and I decided use it directly without using wrapper library.
Currently I download jsapi file from https://www.google.com/jsapi and rename it to jsapi.js, then move the file to vendor/javascripts/google/jsqpi.js.
Then require the file in application.js.
Now I can use the library I want only to know if this is a right way to use the third party library in rails.
Is there better way than this way?
That is perfectly acceptable. vendor/assets/javascripts is the correct location for third-party javascript files.
Sometimes you can find gems that include third-party javascript libraries and integrate them into the asset pipeline for you (e.g. jquery-ui-rails gem). This is nice because it makes you not responsible for handling the actual files and is easier on your version control software (a single line in your Gemfile vs entire files). You can also update the files with bundler. However, this tends to only be practical for really popular libraries. Sometimes you can find gems for the javascript library you are looking for, but the gem hasn't been updated in ages. Of course, you could always roll your own gem that includes the libraries you want.
Have you taken a look at googlecharts gem
its full of examples
I'd like to add source map support on a rails 3.2 application I am working on. As far as I know, generating source maps is not supported by Sprockets and from its github page it looks like the feature is planned for 4.0. I am working with Sprockets 2.2 and I think monkey patching is the only way to go. The module Processing under the main Sprockets module gives access to the js_compressor function which can be patched to generate source map for a single file. But, I don't know how to add this when the JS files combine. I am using Uglifier 2.4 as the compressor.
The project has a mixture of CoffeeScript, JS and EJS files. So, I think this is how sprockets would be compiling them together. First, it would convert Coffeescript and EJS to JS, then use the js_compressor to compress individual files and later concatenate them in groups. Now, as the source map for multiple files combined to the same file is a single file. So, I will need to change the compilation process somewhat and make the js_compressor run over the files, once the concatenation is finished. So, can anyone help out with this? Even explaining the sprockets compilation process and the modules used and functions involved would be of great help. I don't care about making source map files for the CoffeeScript code at present. Even mapping to their converted JS files would do.
Also, would like to add if there is some gem which can help with this it would be most welcome.
Rails 4 does not have source maps either.
As far as I know, and as of today, this will only be part of rails 5.
A really nice approach to solve this right now is implemented in discourse by #SamSaffron and explained here:
https://github.com/discourse/discourse/blob/master/lib/tasks/assets.rake
The gist, add a "before" task to the sprockets precompile process, and hack into the compilation process to generate the sourcemapped files and directives.
The nice thing in this approach is that you don't lose stuff from files that are both js and erb (*.js.erb) which is something quite common in rails.
I think that patching the whole sprockets pipeline is a bit of an abuse and risky.
So I installed Ruby on Rails(first time) and got down to starting a new project and a server. So as expected there was an error on running the Rails server command. Some gems needed to be installed, apparently. The bundle install command didn't work for some wierd ssl issue. So I decided to do it all
manually.
What strikes me as odd is that there's a gem for jQuery: jquery-rails. I don't understand the point of this, really. Why not simply download the jquery file and put it in public.
What's the point of having a gem here.
Is it simply convinience or is there another important reason behind it?
Jquery-rails does 2 things. First of all it bundles the appropriate version of jquery. I consider this only a convenience for jquery itself. For something like jquery-ui, jquery-ui-rails does a lot more: since jquery-ui is modular, that gem will serve to clients only the bits of jquery-ui you are using.
The other thing in jquery-rails is jquery-ujs. This is javascript that makes things such as passing the :remote => true option to form_for work. It used to be that rails itself contained a version of this for prototype, but with rails 3 this was extracted from rails to make it easier to use other javascript libraries than rails' previous default of prototype
I think this is a good idea, because it makes JQuery available as a versioned dependency.
If you need to update JQuery, you just have to change the version at one place in your app, and every page that needs it will use the new version.
And based on its homepage, there's also a test helper that you can use in your tests.
How am I supposed to use bootstap with rails 3.0 rather than >= 3.1 ? is there any plugin which supports rails 3.0 ?
I think all of the bootstrap gems require Rails 3.1 or greater. I recently had bootstrap on a 3.0.10 Rails app using the Less.js file that you download from their site: http://lesscss.org/. This is the simplest most basic way to use Twitter-Bootstrap; the file compiles all of your "my_file.less" files into css on the client side.
However, if you want to modify the variables (which is the real power of using this framework) than you need to compile it. You can take a look at this Less compiler: http://wearekiss.com/simpless. I've never tried that, but I hear good things about it and it works on Mac, Linux, or PC.
Probably the easiest thing to do - if you want to compile the code on server side - would be to upgrade your project to Rails 3.1.1 and just use one of the Twitter Bootstrap gems. This is actually exactly what I ended up doing. I was able to update my app to 3.1.1 and I used the Boostrap-Sass gem (just because I slightly prefer Sass).
If you decide to upgrade, follow this RailsCast: http://railscasts.com/episodes/282-upgrading-to-rails-3-1
It helped me a lot.
Ryan Bates also offers a video on how to incorporate Twitter Bootstrap into a Rails app: http://railscasts.com/episodes/328-twitter-bootstrap-basics.
Here's a link to the Sass version of Bootstrap that I am currently using: https://github.com/thomas-mcdonald/bootstrap-sass
Many solutions : you can upgrade to rails 3.1+, might be the better (not the easier, depending on you app) way. You can include the static files yourself if you don't intend to change anything that is handled at the less level. You can do it even if you intend to, but you'll have to recompile the files yourself (or find a way to automate it). Finally, there might be a gem out there that is compatible with rails pre-asset-pipeline, or an old version of a gem. You'll have to look for yourself if you absolutely want a gem.
I have features I would like to be portable between my own Rails applications.
I wonder if I should create a gem or a plugin for each feature I want to be portable (sharable).
They are just for Rails (for now) because they include css, html, js and image files.
But I have been wondering, the things provided with plugins could be provided with gems too but not the opposite? So maybe it's better to learn how to create gems, because then you I don't have to learn how to create both gems and plugins? And gems seem to be more popular these days.
But then, from what I can understand one gem is shared between all rails app in the OS. So that means I can not customize it for each Rails app right? In that case, maybe creating a plugin is better cause it should be allowed to customize (editing css, js etc) each feature and to have it stored inside the Rails app itself and not in the OS level.
Some advices would be appreciated!
UPDATE:
So gem works great with css, html, js and image files? In a plugin I think you can have a MVC, your own models, views and controllers. Quoted from Rails guides "Storing models, views, controllers, helpers and even other plugins in your plugins". Is this possible too in a gem? Eg. I want to add a extension that gives me a nice Shopping cart (with own migrations, mvc, asset files) that will be hooked into the current Rails app. Is this possible as gem or only as plugin?
You're right that gems offer a little more than plugins. Versioning and dependencies on other gems being the main ones for me.
One gem needn't be shared across everything using ruby. You can install multiple versions of a single gem and specify in your environment.rb that a gem requires a specific version. E.g.
config.gem 'my-gem', :version => '1.2.3'
Also you can freeze gems into your rails application so that you know you are working with a specific version.
You might want to look at the jeweler gem which makes creating your own gems easier.
UPDATE
To include CSS, javascript etc I think you'll need to make an Rails engine which can then be bundled as a plugin or a gem. I've not done this but there's some coverage here and here.
The push with Rails 3 seems to be towards gems and away from plugins as a lot of support has been added to make gems work as well or better than plugins ever did. A well constructed gem is a great thing to have and share between different applications, and also reduces the amount of testing you will have to do since you can test the gem thoroughly before integration.
For extensions to Rails that use CSS, HTML and other assets, it might be that you need to build an engine to bundle this all up and allow it to fit neatly into an application.
As of Rails 4, plugins will no longer be supported.
Gems are the way forward.