Add filter method

Author: Kenneth Geerts

lib/json_logic.rb

@@ -4,12 +4,16 @@
 
 module JSONLogic
   def self.apply(logic, data)
-    return logic unless logic.is_a?(Hash)             # pass-thru
-    operator, values = logic.first                    # unwrap single-key hash
-    values = [values] unless values.is_a?(Array)      # syntactic sugar
-    values.map! { |value| apply(value, data) }        # recursion step
-    values.flatten!(1) if values.size == 1            # [['A']] => ['A']
-    Operation.perform(operator, values, data || {})   # perform operation
+    return logic unless logic.is_a?(Hash)                # pass-thru
+    operator, values = logic.first                       # unwrap single-key hash
+    values = [values] unless values.is_a?(Array)         # syntactic sugar
+    new_vals = values.map { |value| apply(value, data) } # recursion step
+    new_vals.flatten!(1) if new_vals.size == 1           # [['A']] => ['A']
+    Operation.perform(operator, new_vals, data || {})    # perform operation
+  end
+
+  def self.filter(logic, data)
+    data.select { |d| apply(logic, d) }
   end
 end
 

test/json_logic_test.rb

@@ -19,4 +19,10 @@ class JSONLogicTest < Minitest::Test
     end
     count += 1
   end
+
+  def test_filter
+    filter = JSON.parse(%Q|{">": [{"var": "id"}, 1]}|)
+    data = JSON.parse(%Q|[{"id": 1},{"id": 2}]|)
+    assert_equal([{'id' => 2}], JSONLogic.filter(filter, data))
+  end
 end