binlib/sql/template: add 'locals' method.

binlib/sql/template.rb

@@ -7,8 +7,7 @@ class SQL::Template
 
   def context
     context = binding
-    context.local_variable_set(:languages, %w[ar en pt fa].map { SQL::Language.new(_1) })
+    locals.each { context.local_variable_set(_1, _2) }
-    context.local_variable_set(:chapter_id, 1)
     context
   end
 
@@ -26,4 +25,13 @@ class SQL::Template
       chapter_id, verse.content
     ].map { Integer === _1 ? _1 : SQL::Utils.escape(_1) }.join(",")
   end
+
+  private
+
+  def locals
+    {
+      languages: %w(ar en pt fa).map { SQL::Language.new(_1) },
+      chapter_id: 1
+    }
+  end
 end