On: Publishing JSON-LD for Developers

[igravious]

Awesome, I love messing with Ruby and semantic web stuff. Thanks for posting this. Could you explain more? How do you implement the strongly-typed feature? How does it interoperate with the Ruby-RDF library? https://github.com/ruby-rdf

[dogweather → igravious]

Here's a quick example. Put this in a Rails template:

  <%= WebSite.new(
        name: 'Texas Public Law',
        url:  'https://texas.public.law',
      )%>

...and you'll see this in the HTML:

  <script type="application/ld+json">
  {
    "@context": "http://schema.org",
    "@type": "WebSite",
    "name": "Texas Public Law",
    "url": "https://texas.public.law"
  }
  </script>

This DRY's up my code - I just encode the right way of forming JSON-LD and the correct objects and attributes in one place, the library. (That JSON-LD is from my live site, https://texas.public.law)

Details:

First I created a small library which wraps Rails ActiveModel Validations so they can be used in any Ruby object. And I supply a new validator, TypeValidator.

https://github.com/public-law/validated_object

With this building block, I can create classes for each Schema type I care about. And they strictly enforce their attributes:

  class Organization < SchemaType
    attr_accessor founding_date
    validates founding_date, type: Date
  end

That's a little redundant, but to a Rails developer, it's immediately clear what's going on. The full Organization code: https://github.com/public-law/schema-dot-org/blob/master/lib...

I'm not using Ruby-RDF at all. I looked into the current Ruby meta-data and strong typing work, and found it all too complex for my simpler use case:

I'm creating websites, and I want to embed correct JSON-LD-formatted schema.org in a rock-solid way: (1) Correct syntax, and (2) correct semantics. I've got the information as Rails models and objects, and I need to convert this to HTML/JSON-LD.

So all of these objects, like Organization above, recursively creates proper markup in response to #to_s:

  <%= @an_organization %>

...instantiated from that class above, will result in this in the generated HTML page:

  <script type="application/ld+json">
  {
    "@context": "http://schema.org",
    "@type": "Organization",

etc.

https://github.com/public-law/schema-dot-org#usage

[igravious → dogweather]

Thanks for the in-depth explanation. Sounds really great. I'll add it to my Ruby RDF toolkit.

What do you think of Spira https://github.com/ruby-rdf/spira , does it complement what you are doing in any way?

[dogweather → igravious]

That's pretty cool! But yeah, I don't have any RDF data sources. I parse lots of plain text and PDFs, and import some databases directly.

And for generating the website metadata, that info is coming from the Rails models.