Use DB::Serializable instead of DB.mapping. (#996)

* Use DB::Serializable instead of DB.mapping. Fixes #364

* bump to latest PG and DB shards to ensure everything works. Fixing compilation errors

shard.yml

@@ -18,7 +18,7 @@ dependencies:
     version: ~> 0.3.0
   pg:
     github: will/crystal-pg
-    version: ~> 0.27.0
+    version: ~> 0.28.0
   habitat:
     github: luckyframework/habitat
     version: ~> 0.4.7

src/avram/associations.cr

@@ -20,7 +20,9 @@ module Avram::Associations
     end
 
     # Returns `true` if the association has been preloaded
+    @[DB::Field(ignore: true)]
     getter? {{ assoc_name }}_preloaded : Bool = false
+    @[DB::Field(ignore: true)]
     private getter _preloaded_{{ assoc_name }} : {{ model }}?
   end
 

src/avram/associations/has_many.cr

@@ -170,7 +170,9 @@ module Avram::Associations::HasMany
   end
 
   private macro define_has_many_lazy_loading(assoc_name, model, foreign_key, through)
+    @[DB::Field(ignore: true)]
     @_preloaded_{{ assoc_name }} : Array({{ model }})?
+    @[DB::Field(ignore: true)]
     getter? {{ assoc_name }}_preloaded : Bool = false
 
     def _preloaded_{{ assoc_name }}=(vals : Array({{ model }})) : Array({{ model }})

src/avram/model.cr

@@ -8,17 +8,11 @@ abstract class Avram::Model
   include Avram::Polymorphic
   include Avram::SchemaEnforcer
 
-  module JSONConverter(T)
-    def self.from_rs(rs : DB::ResultSet)
-      value = rs.read(JSON::PullParser?)
-      T.new(value) if value
-    end
-  end
-
   macro inherited
     COLUMNS      = [] of Nil # types are not checked in macros
     ASSOCIATIONS = [] of Nil # types are not checked in macros
     include LuckyCache::Cachable
+    include DB::Serializable
   end
 
   def self.primary_key_name : Symbol?
@@ -67,7 +61,6 @@ abstract class Avram::Model
     class_getter table_name : String = Avram::TableFor.table_for({{ @type.id }})
     {% end %}
     setup(Avram::Model.setup_initialize)
-    setup(Avram::Model.setup_db_mapping)
     setup(Avram::Model.setup_getters)
     setup(Avram::Model.setup_column_info_methods)
     setup(Avram::Model.setup_association_queries)
@@ -88,7 +81,6 @@ abstract class Avram::Model
       class_getter table_name : String = Avram::TableFor.table_for({{ @type.id }})
     {% end %}
     setup(Avram::Model.setup_initialize)
-    setup(Avram::Model.setup_db_mapping)
     setup(Avram::Model.setup_getters)
     setup(Avram::Model.setup_column_info_methods)
     setup(Avram::Model.setup_association_queries)
@@ -182,30 +174,6 @@ abstract class Avram::Model
     end
   end
 
-  # Setup [database mapping](http://crystal-lang.github.io/crystal-db/api/latest/DB.html) for the model's columns.
-  #
-  # NOTE: Avram::Migrator saves `Float` columns as numeric which are converted
-  # in the avram/charms/float64_extensions.cr file
-  macro setup_db_mapping(columns, *args, **named_args)
-    DB.mapping({
-      {% for column in columns %}
-        {{column[:name]}}: {
-          {% if column[:type].id == Array(Float64).id %}
-            type: Array(PG::Numeric),
-          {% elsif column[:type].is_a?(Generic) || column[:serialized] %}
-            type: {{column[:type]}},
-          {% else %}
-            type: {{column[:type]}}::Lucky::ColumnType,
-          {% end %}
-          nilable: {{column[:nilable]}},
-          {% if column[:serialized] %}
-          converter: JSONConverter({{column[:type]}}),
-          {% end %}
-        },
-      {% end %}
-    })
-  end
-
   macro setup_association_queries(associations, *args, **named_args)
     {% for assoc in associations %}
       def {{ assoc[:assoc_name] }}_query
@@ -257,6 +225,21 @@ abstract class Avram::Model
       {% value = nil %}
     {% end %}
 
+    @[DB::Field(
+      ignore: false,
+      key: {{ type_declaration.var }},
+      {% if is_serialized %}
+      converter: JSONConverter({{ data_type }}),
+      {% elsif data_type.id == Array(Float64).id %}
+      converter: PG::NumericArrayFloatConverter,
+      {% end %}
+    )]
+    {% if data_type.is_a?(Generic) || is_serialized %}
+      @{{ type_declaration.var }} : {{ data_type }}{% if nilable %}?{% end %}
+    {% else %}
+      @{{ type_declaration.var }} : {{ data_type }}::Lucky::ColumnType{% if nilable %}?{% end %}
+    {% end %}
+
     {% COLUMNS << {name: type_declaration.var, type: data_type, nilable: nilable.id, autogenerated: autogenerated, value: value, serialized: is_serialized, allow_blank: allow_blank} %}
   end
 

src/ext/pg/json_converter.cr

@@ -0,0 +1,8 @@
+# This is used for serialized JSON objects.
+# e.g. `column theme : Theme, serialize: true`
+module JSONConverter(T)
+  def self.from_rs(rs : DB::ResultSet)
+    value = rs.read(JSON::PullParser?)
+    T.new(value) if value
+  end
+end

src/ext/pg/numeric_array_float_converter.cr

@@ -0,0 +1,12 @@
+# Extends the PG shard and adds a converter for
+# converting `Array(PG::Numeric)` columns to `Array(Float64)`. This
+# can be used with raw SQL queries.
+# ```
+# @[DB::Field(converter: PG::NumericArrayFloatConverter)]
+# property average_amount : Array(Float64)
+# ```
+module PG::NumericArrayFloatConverter
+  def self.from_rs(rs : DB::ResultSet)
+    rs.read(Array(PG::Numeric)).map(&.to_f)
+  end
+end