# Gon gem — get your Rails variables in your js
If you need to send some data to your js files and you don't want to do this with long way through views and parsing - use this force!
Now with [Rabl](https://github.com/nesquena/rabl) support!
## A example of typical use
When you need to send some start data from your controller to your js
you probably doing something like this:
1. Write this data in controller(presenter/model) in some variable
2. In view for this action you put this data in some objects by data
attributes, or write js right in view
3. Then in js it depends - if you previously write data in data
attributes - you should parse this attributes and write data to some
js variable. If you write js right in view (many frontenders shame you for
that) - you just use data from this js - OK.
4. You can use your data in your js
And everytime when you need some data from action to js you do this.
With gon you configure it firstly - just put in layout one tag, and add
gem line to your Gemfile and do two actions:
1. Write variables by gon.variable_name = variable_value
2. In your js you get this by gon.variable_name
3. profit?
## Usage
`app/views/layouts/application.html.erb`
``` erb
some title
<%= include_gon %>
...
```
For camelize your variables in js you can use:
``` erb
some title
<%= include_gon(:camel_case => true) %>
...
```
For different namespace of your variables in js you can use:
``` erb
some title
<%= include_gon(:namespace => 'serverExports') %>
...
```
In action of your controller you put something like this:
``` ruby
@your_int = 123
@your_array = [1,2]
@your_hash = {'a' => 1, 'b' => 2}
gon.your_int = @your_int
gon.your_other_int = 345 + gon.your_int
gon.your_array = @your_array
gon.your_array << gon.your_int
gon.your_hash = @your_hash
gon.all_variables # > {:your_int => 123, :your_other_int => 468, :your_array => [1, 2, 123], :your_hash => {'a' => 1, 'b' => 2}}
gon.your_array # > [1, 2, 123]
gon.clear # gon.all_variables now is {}
```
In javascript file for view of this action write call to your variable:
``` js
alert(gon.your_int)
alert(gon.your_other_int)
alert(gon.your_array)
alert(gon.your_hash)
```
With camelize:
``` js
alert(gon.yourInt)
alert(gon.yourOtherInt)
alert(gon.yourArray)
alert(gon.yourHash)
```
With custom namespace and camelize:
``` js
alert(customNamespace.yourInt)
alert(customNamespace.yourOtherInt)
alert(customNamespace.yourArray)
alert(customNamespace.yourHash)
```
## Usage with Rabl
Now you can write your variables assign logic in templates with [Rabl](https://github.com/nesquena/rabl).
How write templates very clearly described in their repo.
Profit of using Rabl with gon:
1. You can clean your controllers now!
2. Clear and easy work with database objects and collections
3. All power of Rabl
4. You still can be lazy and don't use common way to transfer data in js
5. And so on
For using gon with Rabl you need to create new Rabl template and map gon
to it.
For example you have model Post with attributes :title and :body.
You want to get all your posts in your js as an Array.
Thats what you need to do:
1. Create Rabl template. I preffer creating special directory for
templates which are not view templates.
`app/goners/posts/index.rabl`
``` rabl
collection @posts => 'posts'
attributes :id, :title, :body
```
2. After that you need only map this template to gon.
`app/controllers/post_controller.rb#index`
``` ruby
def index
# some controller logic
@posts = Post.all # Rabl works with instance variables of controller
gon.rabl 'app/goners/posts/index.rabl'
end
```
Thats it! In your js now you get gon.posts variable which is Array of
post objects with attributes :id, :title and :body.
P.s. If you didn't put include_gon tag in your html head area - it
wouldn't work. You can read about this in common usage above.
### Some tips of usage Rabl with gon:
If you don't use alias in Rabl template:
``` rabl
collection @posts
....
```
instead of using that:
``` rabl
collection @posts => 'alias'
....
```
Rabl will return you array and gon by default put it to variable
gon.rabl
Two way how you can change it - using aliases or you can add alias to
gon mapping method:
``` ruby
# your controller stuff here
gon.rabl 'path/to/rabl/file', :as => 'alias'
```
## Installation
Puts this line into `Gemfile` then run `$ bundle`:
``` ruby
gem 'gon', '2.0.0'
```
Or if you are old-school Rails 2 developer put this into `config/environment.rb` and run `$ rake gems:install`:
``` ruby
config.gem 'gon', :version => '2.0.0'
```
Or manually install gon gem: `$ gem install gon`
## Contributors
* @gazay
Special thanks to @brainopia, @kossnocorp and @ai.
## License
The MIT License
Copyright (c) 2011 gazay
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.