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https://github.com/dnagir/knockout-rails
KnockoutJS for Rails with Sweetness
https://github.com/dnagir/knockout-rails
Last synced: 2 months ago
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KnockoutJS for Rails with Sweetness
- Host: GitHub
- URL: https://github.com/dnagir/knockout-rails
- Owner: dnagir
- Archived: true
- Created: 2011-11-17T02:32:27.000Z (about 13 years ago)
- Default Branch: main
- Last Pushed: 2024-05-18T15:41:40.000Z (9 months ago)
- Last Synced: 2024-11-08T16:53:42.467Z (3 months ago)
- Language: CoffeeScript
- Homepage:
- Size: 237 KB
- Stars: 96
- Watchers: 10
- Forks: 16
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- Changelog: HISTORY.md
Awesome Lists containing this project
- awesome-knockout - Rails - KnockoutJS for Rails (Integrations)
README
# Knockout - easily use Knockout.js from the Rails app
If you have any questions please contact me [@dnagir](http://www.ApproachE.com).
This provides a set of conveniences for you to use more like Backbone or Spine, but still fully leveraging KnockoutJS.
# Install
Add it to your Rails application's `Gemfile`:
```ruby
gem 'knockout-rails'
```
Then `bundle install`.
Reference `knockout` from your JavaScript as you normally do with Rails 3.1 Assets Pipeline.
# Usage
## Model
After you've referenced the `knockout` you can create your first persistent Model.
```coffee
class @Page extends ko.Model
@persistAt 'page' # This is enough to save the model RESTfully to `/pages/{id}` URL
@fields 'id', 'name', 'whatever' # This is optional and will be inferred if not used
```
Too simple. This model conforms to the response of [inherited_resources](https://github.com/josevalim/inherited_resources) Gem.
Now you can create the model in your HTML.
*Note* that we don't do a roundtrip to fetch the data as we already have it when rendering the view.
```haml
= content_for :script do
:javascript
jQuery(function(){
// Create the viewModel with prefilled data
window.page = new Page(#{@page.to_json});
ko.applyBindings(window.page); // And bind everything
});
```
Of course you can manipulate the object as you wish:
```coffee
page.name 'Updated page'
page.save() # saves it to the server using PUT: /pages/123
page.name '' # Assign an invalid value that is validated on the server
request = page.save() # returns the jQuery Deferred, so you can chain into it when necessary
request.always (xhr, status) ->
# The response is 422 with JSON: {name: ["invalid name", "should not be blank"]}
# And now we have the errors set automatically!
page.errors.name() # "invalid name, should not be blank"
# even more than that, errors are already bound and shown in the HTML (see the view below)
```
Now let's see how we can show the validation errors on the page and bind everything together.
```haml
%form.page.formtastic{:data => {:bind =>'submit: save'}}
%fieldset
%ol
%li.input.string
%label.label{:for=>:page_name} Name
%input#page_name{:type=>:text, :data=>{:bind=>'value: name'}}
%span.inline-error{:data=>{:bind=>'visible: errors.name, text: errors.name'}}
```
## Model Validations
If you are using the model, you can also take advantage of the client-side validation framework.
The client side validation works similarly to the server-side validation.
This means there is only one place to check for errors, no matter where those are defined.
For example - `page.errors.name()` returns the error message for the `name` field for both client and server side validations.
The piece of code below should explain client-side validation, including some of the options.
```coffee
class @Page extends ko.Model
@persistAt 'page'
@validates: ->
@acceptance 'agree_to_terms' # Value is truthy
@presence 'name', 'body' # Non-empty, non-blank stringish value
@email 'author' # Valid email, blanks allowed
@presence 'password'
@confirmation 'passwordConfirmation', {confirms: 'password'} # Blanks allowed
# numericality:
@numericality 'rating'
@numericality 'rating', min: 1, max: 5
# Inclusion/exclusion
@inclusion 'subdomain', values: ["mine", "yours"]
@exclusion 'subdomain', values: ["www", "www2"]
@format 'code', match: /\d+/ # Regex validation, blanks allowed
@length 'name', min: 3, max: 10 # Stringish value should be with the range
# Custom message
@presence 'name', message: 'give me a name, yo!'
# Conditional validation - access model using `this`
@presence 'name', only: -> @persisted(), except: -> @id() > 5
# Custom inline validation
@custom 'name', (page) ->
if (page.name() || '').indexOf('funky') < 0 then "should be funky" else null
```
It is recommended to avoid custom inline validations and create your own validators instead (and maybe submit it as a Pull Request):
```coffee
ko.Validations.validators.funky = (model, field, options) ->
# options - is an optional set of options passed to the validator
word = options.word || 'funky'
if model[field]().indexOf(word) < 0 "should be #{word}" else null
```
so that you can use it like so:
```coffee
@validates: ->
funky 'name', word: 'yakk'
```
Here's how you would check whether the model is valid or not (assuming presence validation on `name` field):
```coffee
page = new @Page name: ''
page.isValid() # false
page.errors.name() # "can't be blank"
page.name = 'Home'
page.isValid() # true
page.errors.name() # null
```
Every validator has its own set of options. But the following are applied to all of them (including yours):
- `only: -> truthy or falsy` - only apply the validation when the condition is truthy. `this` points to the model so you can access it.
- `except:` - is the opposite to only. Both `only` and `except` can be used, but you should make sure those are not mutually exclusive.
And at the end of this exercise, you can bind the errors using `data-bind="text: page.error.name"` or any other technique.
## Model Events
```coffee
class @Page extends ko.Model
@persistAt 'page'
# Subscribe to 'sayHi' event
@upon 'sayHi', (name) ->
alert name + @name
page = Page.new name: 'Home'
page.trigger 'sayHi', 'Hi '
# will show "Hi Home"
```
## Model Callbacks
The callbacks are just convenience wrappers over the predefined events.
Some of them are:
```coffee
class @Page extends ko.Model
@persistAt 'page'
@beforeSave ->
@age = @birthdate - new Date()
# This would be similar to
class @Page extends ko.Model
@persistAt 'page'
@on 'beforeSave', ->
@age = @birthdate - new Date()
```
## Bindings
This gem also includes useful bindings that you may find useful in your application.
For example, you can use `autosave` binding by requiring `knockout/bindings/autosave`.
Or if you want to include all of the bindings available, then require `knockout/bindings/all`.
The list of currently available bindings:
- `autosave` - automatically persists the model whenever any of its attributes change.
Apply it to a `form` element. Examples: `autosave: page`, `autosave: {model: page, when: page.isEnabled, unless: viewModel.doNotSave }`. *NOTE*: It will not save when a model is not valid.
- `inplace` - converts the input elements into inplace editing with 'Edit'/'Done' buttons. Apply it on `input` elements similarly to the `value` binding.
- `color` - converts an element into a color picker. Apply it to a `div` element: `color: page.fontColor`. Depends on [pakunok](https://github.com/dnagir/pakunok) gem (specifically - its `colorpicker` asset).
- `onoff` - Converts checkboxes into iOS on/off buttons. Example: `onoff: page.isPublic`. It depends on [ios-chechboxes](https://github.com/dnagir/ios-checkboxes) gem.
- `animate` - runs the animation when dependent attributes change. Example: `animate: {width: quotaUsed, height: quotaUsed(), duration: 2000}`.
- `autocomplete` - supports jQuery UI autocomplete. Example: `autocomplete: {source: arrayOrObservableOrAnyObjectOrDeferred, select: observableToSetTheValueTo, label: 'nameOfTheFieldToDisplay'}`. The `source` can support `jQuery.Deferred` meaning that you can simply return the result of a `jQuery.ajax`.
Please see the specs for more detailed instruction on how to use the specific binding.
# Development
## Help
- Source hosted at [GitHub](https://github.com/dnagir/knockout-rails)
- Report issues and feature requests to [GitHub Issues](https://github.com/dnagir/knockout-rails/issues)
- Ping me on Twitter [@dnagir](https://twitter.com/#!/dnagir)
- Look at the `HISTORY.md` file for current TODO list and other details.
## Setup
Assuming you already cloned the repo in cd-d into it:
```bash
bundle install
# Now run the Ruby specs
bundle exec rspec spec/
# Now start JavaScript server for specs:
cd spec/dummy
bundle exec rails s
# go to http://localhost:3000/jasmine to see the results
```
Now you can go to `spec/javascripts` and start writing your specs and then modify stuff in `lib/assets/javascripts` to pass those.
Pull requests are very welcome, but please include the specs! It's extremely easy to write those!
# License
[MIT] (http://www.opensource.org/licenses/mit-license.php)