Run json/graphql requests and parse responses in an easy way.
The package can be installed by adding yson to your list of dependencies in mix.exs:
def deps do
[
{:yson, "~> 0.2.2"}
]
endyson can be used both to run GraphQL requests and to parse JSON responses.
First create a Yson.GraphQL.Schema object:
defmodule User do
use Yson.GraphQL.Schema
query :user do # defines a query on :user
arg :person do
arg(:full_name, :string)
end
end
root do
value(:email)
map :person, resolver: &User.person/1 do
interface :natural_person do
value(:first_name)
value(:last_name)
end
interface :legal_person do
value(:company_name)
end
end
end
def person(%{company_name: name}), do: %{full_name: name}
def person(%{first_name: name, last_name: surname}), do: %{full_name: "#{name} #{surname}"}
endThen run a Graphql request using Yson.GraphQL.Api:
alias Yson.GraphQL.Api
variables = %{full_name: "john doe"}
headers = [] #optional
options = [] #optional
{:ok, result} = Api.run(User, variables, "https://mysite.com/graphql", headers, options)The result will be already mapped using resolvers, so it could be something like the following:
%{
user: %{
email: "[email protected]",
person: %{
full_name: "legal name"
}
}
}The Yson.GraphQL.Schema object exposes two methods:
&describe/0, to build the object description.&resolvers/0, to build the object resolvers tree.
that can be combined with the modules Yson.GraphQL.Builder and Yson.Parser.
Yson.GraphQL.Builder.build/2 accepts a Yson description and the variables. It can be used as follows:
iex> Yson.GraphQL.Builder.build(User.describe(), variables)
iex> %{
query: "query ($fullName: String) {\n user(person: {fullName: $fullName}) {\n email\n person {\n ... on LegalPerson {\n companyName\n }\n ... on NaturalPerson {\n firstName\n lastName\n }\n }\n }\n}",
variables: %{full_name: "john doe"}
}Yson.Parser.parse/3 accepts a Yson resolvers tree and the payload (map with atom keys). It can be used as follows:
iex> payload = %{user: %{email: "[email protected]", person: %{companyName: "legal name"}}}
iex> Yson.Parser.parse(User.resolvers(), payload, :snake)
iex> %{
user: %{
email: "[email protected]",
user: %{
full_name: "legal name"
}
}
}Currently there is no implemented Api module for running Json requests, but it is still possible to use yson to parse responses.
The first step is to define a Yson.Json.Schema schema.
defmodule User do
use Yson.Json.Schema
root do # defines the object root
value(:email)
map :person, resolver: &User.person/1 do
interface :natural_person do
value(:first_name)
value(:last_name)
end
interface :legal_person do
value(:company_name)
end
end
end
def person(%{company_name: name}), do: %{full_name: name}
def person(%{first_name: name, last_name: surname}), do: %{full_name: "#{name} #{surname}"}
endYson.Parser.parse/3 accepts a Yson resolvers tree and the payload (map with atom keys). It can be used as follows:
iex> payload = %{email: "[email protected]", person: %{companyName: "legal name"}}
iex> Yson.Parser.parse(User.resolvers(), payload, :snake)
iex> %{email: "[email protected]", user: %{full_name: "legal name"}}The available strategies for key recasing are:
:snaketo convert payload keys to snake case before parsing:camelto convert payload keys to camel case before parsing:no_caseto preserve the original casing