Prmd
JSON Schema tooling: scaffold, verify, and generate documentation from JSON Schema documents.
Introduction
JSON Schema provides a great way to describe an API. prmd provides tools for bootstrapping a description like this, verifying its completeness, and generating documentation from the specification.
To learn more about JSON Schema in general, start with this excellent guide and supplement with the specification. The JSON Schema usage conventions expected by prmd specifically are described in /docs/schemata.md.
Installation
Install the command-line tool with:
$ gem install prmd
If you're using prmd within a Ruby project, you may want to add it to the application's Gemfile:
gem 'prmd'
$ bundle install
Usage
Prmd provides four main commands:
init
: Scaffold resource schematacombine
: Combine schemata and metadata into single schemaverify
: Verify a schemadoc
: Generate documentation from a schemarender
: Render views from schema
Here's an example of using these commands in a typical workflow:
# Fill out the resource schemata
$ mkdir -p schemata
$ prmd init app > schemata/app.json
$ prmd init user > schemata/user.json
$ vim schemata/{app,user}.json # edit scaffolded files
# Provide top-level metadata
$ cat <<EOF > meta.json
{
"description": "Hello world prmd API",
"id": "hello-prmd",
"links": [{
"href": "https://api.hello.com",
"rel": "self"
}],
"title": "Hello Prmd"
}
EOF
# Combine into a single schema
$ prmd combine --meta meta.json schemata/ > schema.json
# Check itβs all good
$ prmd verify schema.json
# Build docs
$ prmd doc schema.json > schema.md
Using YAML instead of JSON as a resource and meta format
init
and combine
supports YAML format:
# Generate resources in YAML format
$ prmd init --yaml app > schemata/app.yml
$ prmd init --yaml user > schemata/user.yml
# Combine into a single schema
$ prmd combine --meta meta.json schemata/ > schema.json
combine
can detect both *.yml
and *.json
and use them side by side. For example, if one have a lot of legacy JSON resources and wants to create new resources in YAML format - combine
will be able to handle it properly.
Render from schema
$ prmd render --template schemata.erb schema.json > schema.md
Typically you'll want to prepend header and overview information to
your API documentation. You can do this with the --prepend
flag:
$ prmd doc --prepend overview.md schema.json > schema.md
You can also chain commands together as needed, e.g.:
$ prmd combine --meta meta.json schemata/ | prmd verify | prmd doc --prepend overview.md > schema.md
See prmd <command> --help
for additional usage details.
Documentation rendering settings
Out of the box you can supply a settings file (in either JSON
or YAML
) that will tweak the layout of your documentation.
$ prmd doc --settings config.json schema.json > schema.md
Available options (and their defaults)
{
"doc": {
"url_style": "default", // can also be "json"
"disable_title_and_description": false, // remove the title and the description, useful when using your own custom header
"toc": false // insert the table of content for json scheme documentation to the top of the file. (default disable)
}
}
Use as rake task
In addition, prmd can be used via rake tasks
# Rakefile
require 'prmd/rake_tasks/combine'
require 'prmd/rake_tasks/verify'
require 'prmd/rake_tasks/doc'
namespace :schema do
Prmd::RakeTasks::Combine.new do |t|
t.options[:meta] = 'schema/meta.json' # use meta.yml if you prefer YAML format
t.paths << 'schema/schemata/api'
t.output_file = 'schema/api.json'
end
Prmd::RakeTasks::Verify.new do |t|
t.files << 'schema/api.json'
end
Prmd::RakeTasks::Doc.new do |t|
t.files = { 'schema/api.json' => 'schema/api.md' }
end
end
task default: ['schema:combine', 'schema:verify', 'schema:doc']
File Layout
We suggest the following file layout for JSON schema related files:
/docs (top-level directory for project documentation)
/schema (API schema documentation)
/schemata
/{resource.[json,yml]} (individual resource schema)
/meta.[json,yml] (overall API metadata)
/overview.md (preamble for generated API docs)
/schema.json (complete generated JSON schema file)
/schema.md (complete generated API documentation file)
where [json,yml]
means that it could be either json
or yml
.
Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create new Pull Request