[postgres] allow returning string values for (JDBC) arrays with (fixes #510)

... due compatibility with AR < 4.0 (and gems that depend on previous func)

Author: kares

lib/arjdbc/postgresql/adapter.rb

@@ -1412,6 +1412,7 @@ def jdbc_column_class
     end
 
     if ActiveRecord::VERSION::MAJOR < 4 # Rails 3.x compatibility
+      PostgreSQLJdbcConnection.raw_array_type = true if PostgreSQLJdbcConnection.raw_array_type? == nil
       PostgreSQLJdbcConnection.raw_hstore_type = true if PostgreSQLJdbcConnection.raw_hstore_type? == nil
     end
 

src/java/arjdbc/postgresql/PostgreSQLRubyJdbcConnection.java

@@ -458,6 +458,9 @@ protected IRubyObject timestampToRuby(final ThreadContext context,
     protected IRubyObject arrayToRuby(final ThreadContext context,
         final Ruby runtime, final ResultSet resultSet, final int column)
         throws SQLException {
+        if ( rawArrayType == Boolean.TRUE ) { // pre AR 4.0 compatibility
+            return runtime.newString( resultSet.getString(column) );
+        }
         // NOTE: avoid `finally { array.free(); }` on PostgreSQL due :
         // java.sql.SQLFeatureNotSupportedException:
         // Method org.postgresql.jdbc4.Jdbc4Array.free() is not yet implemented.
@@ -552,6 +555,29 @@ private String formatInterval(final Object object) {
         return str.toString();
     }
 
+    protected static Boolean rawArrayType;
+    static {
+        final String arrayRaw = System.getProperty("arjdbc.postgresql.array.raw");
+        if ( arrayRaw != null ) rawArrayType = Boolean.parseBoolean(arrayRaw);
+    }
+
+    @JRubyMethod(name = "raw_array_type?", meta = true)
+    public static IRubyObject useRawArrayType(final ThreadContext context, final IRubyObject self) {
+        if ( rawArrayType == null ) return context.getRuntime().getNil();
+        return context.getRuntime().newBoolean(rawArrayType);
+    }
+
+    @JRubyMethod(name = "raw_array_type=", meta = true)
+    public static IRubyObject setRawArrayType(final IRubyObject self, final IRubyObject value) {
+        if ( value instanceof RubyBoolean ) {
+            rawArrayType = ((RubyBoolean) value).isTrue() ? Boolean.TRUE : Boolean.FALSE;
+        }
+        else {
+            rawArrayType = value.isNil() ? null : Boolean.TRUE;
+        }
+        return value;
+    }
+
     protected static Boolean rawHstoreType;
     static {
         final String hstoreRaw = System.getProperty("arjdbc.postgresql.hstore.raw");

test/db/postgresql/array_compat_test.rb

@@ -0,0 +1,42 @@
+# encoding: utf-8
+require 'test_helper'
+require 'db/postgres'
+
+class PostgreSQLArrayCompatTest < Test::Unit::TestCase
+
+  class PgArray < ActiveRecord::Base
+    self.table_name = 'pg_arrays'
+  end
+
+  def setup
+    @connection = ActiveRecord::Base.connection
+    @connection.execute 'CREATE TABLE "pg_arrays" ("id" serial primary key, "str_2d" character varying(255)[][])'
+    @connection.execute 'ALTER TABLE "pg_arrays" ADD COLUMN "int_1d" integer[] DEFAULT \'{}\''
+    @connection.execute 'ALTER TABLE "pg_arrays" ADD COLUMN "bool_1d" boolean[]'
+
+    @connection.execute "INSERT INTO \"pg_arrays\"(bool_1d, str_2d, int_1d) " <<
+      " VALUES ('{f, t, t}', '{{\"a\",\"b\"}, {\"c\",\"d\"}}', '{1, 2, 3}')"
+  end
+
+  def teardown
+    @connection.execute 'DROP TABLE IF EXISTS pg_arrays'
+  end
+
+  def test_column_types
+    int_1d_column = PgArray.columns.find { |c| c.name == 'int_1d' }
+    assert_equal :string, int_1d_column.type
+    assert_equal 'integer[]', int_1d_column.sql_type
+
+    bool_1d_column = PgArray.columns.find { |c| c.name == 'bool_1d' }
+    assert_equal :string, bool_1d_column.type
+    assert_equal 'boolean[]', bool_1d_column.sql_type
+  end
+
+  def test_column_values
+    assert arr = PgArray.first
+    assert_equal "{{a,b},{c,d}}", arr.str_2d
+    assert_equal "{1,2,3}", arr.int_1d
+    assert_equal "{f,t,t}", arr.bool_1d
+  end
+
+end if ActiveRecord::VERSION::MAJOR < 4