Merge pull request #39 from rayokota/simplify-bindings

Simpifly passing of bindings

Author: rayokota

src/jsonata/jsonata.py

@@ -31,7 +31,7 @@
 import sys
 import threading
 from dataclasses import dataclass
-from typing import Any, Callable, Mapping, MutableSequence, Optional, Sequence, Type, MutableMapping
+from typing import Any, Callable, Mapping, MutableSequence, Optional, Sequence, Type, MutableMapping, Union
 
 from jsonata import functions, jexception, parser, signature as sig, timebox, utils
 
@@ -1976,7 +1976,7 @@ def is_output_convert_nulls(self) -> bool:
     def set_output_convert_nulls(self, output_convert_nulls: bool) -> None:
         self.output_convert_nulls = output_convert_nulls
 
-    def evaluate(self, input: Optional[Any], bindings: Optional[Frame] = None) -> Optional[Any]:
+    def evaluate(self, input: Optional[Any], bindings: Optional[Union[Frame, Mapping[str, Any]]] = None) -> Optional[Any]:
         # throw if the expression compiled with syntax errors
         if self.errors is not None:
             raise jexception.JException("S0500", 0)
@@ -1986,7 +1986,9 @@ def evaluate(self, input: Optional[Any], bindings: Optional[Frame] = None) -> Op
             # var exec_env
             # the variable bindings have been passed in - create a frame to hold these
             exec_env = self.create_frame(self.environment)
-            for k, v in bindings.bindings.items():
+            # accept either a Frame or a plain mapping (e.g. dict) of variable bindings
+            items = bindings.bindings if isinstance(bindings, Jsonata.Frame) else bindings
+            for k, v in items.items():
                 exec_env.bind(k, v)
         else:
             exec_env = self.environment

tests/jsonata_test.py

@@ -104,6 +104,29 @@ def test_path(self):
         print(str(data))
         self.eval_expr("foo.bar", data, None, 42, None)
 
+    def test_dict_bindings(self):
+        data = {
+            "products": [
+                {"name": "Apple", "price": 1.20},
+                {"name": "Banana", "price": 0.50},
+                {"name": "Cherry", "price": 2.50},
+            ]
+        }
+        expr = jsonata.Jsonata(
+            "products[price <= $maxPrice]"
+            ".(name & ' costs ' & $currencySymbol & $string(price))"
+        )
+        expected = ["Apple costs $1.2", "Banana costs $0.5"]
+
+        # A plain dict can be passed directly as the bindings.
+        assert expr.evaluate(data, bindings={"maxPrice": 1.50, "currencySymbol": "$"}) == expected
+
+        # A Frame is still accepted for backward compatibility.
+        binding_frame = jsonata.Jsonata.Frame(None)
+        binding_frame.bind("maxPrice", 1.50)
+        binding_frame.bind("currencySymbol", "$")
+        assert expr.evaluate(data, bindings=binding_frame) == expected
+
     def run_case(self, name):
         if not self.run_test_suite(name):
             raise Exception()