Add ability to ignore struct types in schema

Replaces alecthomas#32, thanks to alecthomas#35 fixing the other part of it anyway.

fixtures/ignore_type.json

@@ -0,0 +1,115 @@
+{
+  "$schema": "http:\/\/json-schema.org\/draft-04\/schema#",
+  "$ref": "#\/definitions\/TestUser",
+  "definitions": {
+    "GrandfatherType": {
+      "properties": {},
+      "additionalProperties": true,
+      "type": "object"
+    },
+    "TestUser": {
+      "required": [
+        "some_base_property",
+        "some_base_property_yaml",
+        "grand",
+        "SomeUntaggedBaseProperty",
+        "id",
+        "name",
+        "TestFlag",
+        "age",
+        "email"
+      ],
+      "properties": {
+        "SomeUntaggedBaseProperty": {
+          "type": "boolean"
+        },
+        "TestFlag": {
+          "type": "boolean"
+        },
+        "age": {
+          "maximum": 120,
+          "exclusiveMaximum": true,
+          "minimum": 18,
+          "exclusiveMinimum": true,
+          "type": "integer"
+        },
+        "birth_date": {
+          "type": "string",
+          "format": "date-time"
+        },
+        "email": {
+          "type": "string",
+          "format": "email"
+        },
+        "feeling": {
+          "oneOf": [
+            {
+              "type": "string"
+            },
+            {
+              "type": "integer"
+            }
+          ]
+        },
+        "friends": {
+          "items": {
+            "type": "integer"
+          },
+          "type": "array",
+          "description": "list of IDs, omitted when empty"
+        },
+        "grand": {
+          "$schema": "http:\/\/json-schema.org\/draft-04\/schema#",
+          "$ref": "#\/definitions\/GrandfatherType"
+        },
+        "id": {
+          "type": "integer"
+        },
+        "name": {
+          "maxLength": 20,
+          "minLength": 1,
+          "pattern": ".*",
+          "type": "string",
+          "title": "the name",
+          "description": "this is a property",
+          "default": "alex",
+          "examples": [
+            "joe",
+            "lucy"
+          ]
+        },
+        "network_address": {
+          "type": "string",
+          "format": "ipv4"
+        },
+        "photo": {
+          "type": "string",
+          "media": {
+            "binaryEncoding": "base64"
+          }
+        },
+        "some_base_property": {
+          "type": "integer"
+        },
+        "some_base_property_yaml": {
+          "type": "integer"
+        },
+        "tags": {
+          "patternProperties": {
+            ".*": {
+              "additionalProperties": true,
+              "type": "object"
+            }
+          },
+          "type": "object"
+        },
+        "website": {
+          "type": "string",
+          "format": "uri"
+        }
+      },
+      "additionalProperties": false,
+      "type": "object"
+    }
+  }
+}

go.mod

@@ -1 +1 @@
-module github.com/alecthomas/jsonschema
+module github.com/rawlingsj/jsonschema

reflect.go

@@ -100,6 +100,10 @@ type Reflector struct {
 	// ExpandedStruct will cause the toplevel definitions of the schema not
 	// be referenced itself to a definition.
 	ExpandedStruct bool
+
+	// IgnoredTypes defines a slice of types that should be ignored in the schema,
+	// switching to just allowing additional properties instead.
+	IgnoredTypes []interface{}
 }
 
 // Reflect reflects to Schema from a value.
@@ -246,6 +250,22 @@ func (r *Reflector) reflectTypeToSchema(definitions Definitions, t reflect.Type)
 
 // Refects a struct to a JSON Schema type.
 func (r *Reflector) reflectStruct(definitions Definitions, t reflect.Type) *Type {
+	for _, ignored := range r.IgnoredTypes {
+		if reflect.TypeOf(ignored) == t {
+			st := &Type{
+				Type:                 "object",
+				Properties:           map[string]*Type{},
+				AdditionalProperties: []byte("true"),
+			}
+			definitions[t.Name()] = st
+
+			return &Type{
+				Version: Version,
+				Ref:     "#/definitions/" + t.Name(),
+			}
+
+		}
+	}
 	st := &Type{
 		Type:                 "object",
 		Properties:           map[string]*Type{},

reflect_test.go

@@ -82,6 +82,7 @@ var schemaGenerationTests = []struct {
 	{&Reflector{AllowAdditionalProperties: true}, "fixtures/allow_additional_props.json"},
 	{&Reflector{RequiredFromJSONSchemaTags: true}, "fixtures/required_from_jsontags.json"},
 	{&Reflector{ExpandedStruct: true}, "fixtures/defaults_expanded_toplevel.json"},
+	{&Reflector{IgnoredTypes: []interface{}{GrandfatherType{}}}, "fixtures/ignore_type.json"},
 }
 
 func TestSchemaGeneration(t *testing.T) {