Add to_h and to_json to Granite::ORM::Fields

spec/granite_orm_spec.cr

@@ -4,6 +4,7 @@ require "../src/adapter/pg"
 class Todo < Granite::ORM::Base
   adapter pg
   field name : String
+  field priority : Int32
   timestamps
 end
 
@@ -12,4 +13,18 @@ describe Granite::ORM::Base do
     t = Todo.new(name: "Elorest")
     t.name.should eq "Elorest"
   end
+
+  it "should provide a to_h method" do
+    t = Todo.new(name: "test todo", priority: 20)
+    result = { "name" => "test todo", "priority" => 20, "created_at" => nil, "updated_at" => nil }
+
+    t.to_h.should eq result
+  end
+
+  it "should provide a to_json method" do
+    t = Todo.new(name: "test todo", priority: 20)
+    result = %({"name":"test todo","priority":20,"created_at":null,"updated_at":null})
+
+    t.to_json.should eq result
+  end
 end

src/granite_orm/fields.cr

@@ -54,6 +54,30 @@ module Granite::ORM::Fields
       return parsed_params
     end
 
+    def to_h
+      fields = {} of String => Bool | Float32 | Float64 | Int32 | Int64 | String | Time | Nil
+
+      {% for name, type in FIELDS %}
+        {% if type.id == Time.id %}
+          fields["{{name}}"] = {{name.id}}.try(&.to_s("%F %X"))
+        {% elsif type.id == Slice.id %}
+          fields["{{name}}"] = {{name.id}}.try(&.to_s(""))
+        {% else %}
+          fields["{{name}}"] = {{name.id}}
+        {% end %}
+      {% end %}
+      {% if SETTINGS[:timestamps] %}
+        fields["created_at"] = created_at.try(&.to_s("%F %X"))
+        fields["updated_at"] = updated_at.try(&.to_s("%F %X"))
+      {% end %}
+
+      return fields
+    end
+
+    def to_json
+      to_h.to_json
+    end
+
     # Cast params and set fields.
     private def cast_to_field(name, value : DB::Any)
       if !value.nil?