If/Then/Else.draft7

2 files changed, 14 insertions, 0 deletions

diff --git a/jsonschema/_validators.py b/jsonschema/_validators.py
index 2d6d2aa..1107586 100644
--- a/jsonschema/_validators.py
+++ b/jsonschema/_validators.py
@@ -529,3 +529,16 @@ def not_(validator, not_schema, instance, schema):
         yield ValidationError(
             "%r is not allowed for %r" % (not_schema, instance)
         )
+
+
+def if_(validator, if_schema, instance, schema):
+    # FIXME: paths
+    if validator.is_valid(instance, if_schema):
+        if u"then" in schema:
+            then = schema[u"then"]
+            for error in validator.descend(instance, then):
+                yield error
+    elif u"else" in schema:
+        else_ = schema[u"else"]
+        for error in validator.descend(instance, else_):
+            yield error
diff --git a/jsonschema/validators.py b/jsonschema/validators.py
index fd68a9f..fed56a2 100644
--- a/jsonschema/validators.py
+++ b/jsonschema/validators.py
@@ -513,6 +513,7 @@ Draft7Validator = create(
         u"exclusiveMaximum": _validators.exclusiveMaximum,
         u"exclusiveMinimum": _validators.exclusiveMinimum,
         u"format": _validators.format,
+        u"if": _validators.if_,
         u"items": _validators.items,
         u"maxItems": _validators.maxItems,
         u"maxLength": _validators.maxLength,