https://github.com/styd/functionable-json
Generate JSON with JavaScript functions from ruby hash
https://github.com/styd/functionable-json
function javascript json json-generator ruby
Last synced: 2 months ago
JSON representation
Generate JSON with JavaScript functions from ruby hash
- Host: GitHub
- URL: https://github.com/styd/functionable-json
- Owner: styd
- License: mit
- Created: 2019-08-30T17:59:44.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2020-04-17T13:28:09.000Z (over 5 years ago)
- Last Synced: 2025-04-13T05:51:34.611Z (9 months ago)
- Topics: function, javascript, json, json-generator, ruby
- Language: Ruby
- Size: 10.7 KB
- Stars: 9
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
Awesome Lists containing this project
README
[](https://rubygems.org/gems/functionable-json)
[](https://travis-ci.org/styd/functionable-json)
According to [RFC8259](https://tools.ietf.org/html/rfc8259):
> JSON can represent four primitive types (`strings`, `numbers`, `booleans`,
> and `null`) and two structured types (`objects` and `arrays`).
Now, with this gem, you can have the 7th one, `function`.
So, basically, what I'm saying is the json is no longer conform with the
**RFC8259**. The resulting function is not guaranteed to be executable in
JavaScript because it doesn't check what's inside the function. It also cannot
be parsed back into hash. So, use it at your own risk!
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'functionable-json'
```
And then execute:
$ bundle
## Usage
```ruby
{
amount: function(val) {
return '$' + parseFloat(val).toLocaleString();
}
}.to_json
#=> "{\"amount\":function(val) { return '$' + parseFloat(val).toLocaleString(); }}"
```
But, don't go wild just yet because there are limitations:
- You cannot use `if` keyword because the way JavaScript uses it is different from
ruby. Use ternary operators instead.
- Also, don't put multiple functions on the same line. You'll get unexpected result
if you do.
- You should end every statement with `;`.
If you try the above example on your REPL (e.g. `irb` or `pry`) it won't
work since the gem will try to find the file that stores the code. So, you
need to put it on a file and run it.
### How can a JavaScript function be called from Ruby?
Well, technically, it's not a JavaScript function. It's a Ruby method named
`function` that's available in any object. In JavaScript, a form like that is
a _function declaration_, but in Ruby it's a _method invocation_. So, in that case,
`val` needs to already exist before you call it, and it is. Both `function` and
`val` are already methods of an object. If you want to use arguments with
another name, you need to declare them as variables first.
```ruby
arg1, arg2 = nil
{
equality: function(arg1, arg2) {
return arg1 + ' == ' + arg2
}
}.to_json
#=> "{\"equality\":function(arg1, arg2) { return arg1 + ' == ' + arg2 }}"
```
### Use Case
One example use case is [ApexCharts.RB](https://github.com/styd/apexcharts.rb)
formatter or other charting libraries'. You can add tooltip formatter like this:
```erb
<%= line_chart data, tooltip: {y: {formatter: function(val) { return '$' + parseFloat(val).toLocaleString(); }}} %>
```
## License
The gem is available as open source under the terms of the
[MIT License](https://opensource.org/licenses/MIT).