How to do POST request to Grape REST API using params block compatible with Swagger - ruby

Question

I am using grape to build a REST API, I am having some trouble with params options.
This is how I do a POST request:
# Curl Request
# curl -X POST -H "Content-Type:application/json" 0:9292/v1/articles -d '{"title":"hello","body":"world"}'
# {"error":"article is missing"}
# curl -X POST -H "Content-Type:application/json" 0:9292/v1/articles -d '{"article":{title":"hello","body":"world"}}'
# {"error":"article is invalid"}
As you can see if I omit article it fails article missing, If i put article and it fails article invalid.
This is the code, I am using grape-entity.
# Entity
module API
module Entities
class Article < Grape::Entity
expose :title, documentation: { type: 'string', desc: 'Title' }
expose :body, documentation: { type: 'string', desc: 'Body' }
end
end
end
# API
desc "Create an article"
params do
requires :article, type: API::Entities::Article, documentation: { eg: "aklsdfj" }
end
post '/articles' do
puts params
article = Article.create(params(:title, :body))
represent(article, env)
end
# Add Swagger Docs
add_swagger_documentation mount_path: 'api/doc',
api_version: 'v1',
markdown: GrapeSwagger::Markdown::KramdownAdapter,
hide_documentation_path: true,
base_path: Application.config.base_path,
models: [API::Entities::Article]
Specifically the problem is caused by params block, it requires an :article of type API:Entities::Article.
Also note that, I am using add-swagger-documentation, and this code
produces correct swagger documentation, so the solution have to be
fully compatible with swagger. What is the correct usage of params
block without offending the swagger.

Answer 1

I'm not sure what you're trying to accomplish here. I guess you want to change your post method in a way that it accepts a JSON like this:
{ attribute1: value, attribute2: value }
instead of
{ article: { attribute1: value, attribute2: value } }
In this case, you have to change your params block to something like this
params do
requires :attribute1, type: String, documentation: { eg: "aklsdfj" }
requires :attribute2, type: String, documentation: { eg: "aklsdfj" }
end
instead of
params do
requires :article, type: API::Entities::Article, documentation: { eg: "aklsdfj" }
end
The params block above is expecting a JSON containing an article attribute composed by every attribute defined in the entity API::Entities::Article.
In fact, Grape doesn't accept entity objects as a type for a parameter.