From 4848593d8de386a676ad2289d76652b17bf91056 Mon Sep 17 00:00:00 2001
From: Joel Collins <joel@jtcollins.net>
Date: Thu, 9 Jan 2020 22:34:45 +0000
Subject: [PATCH] Started smarter type conversion

---
 .../common/flask_labthings/fields.py          | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/openflexure_microscope/common/flask_labthings/fields.py b/openflexure_microscope/common/flask_labthings/fields.py
index b8eb3d36..46e04e86 100644
--- a/openflexure_microscope/common/flask_labthings/fields.py
+++ b/openflexure_microscope/common/flask_labthings/fields.py
@@ -1 +1,57 @@
+# Marshmallow fields
 from marshmallow.fields import *
+
+# Marshmallow fields to JSON schema types
+# Note: We shouldn't ever need to use this directly. We should go via the apispec converter
+from apispec.ext.marshmallow.field_converter import DEFAULT_FIELD_MAPPING
+
+# Extra standard library Python types
+from datetime import date, datetime, time, timedelta
+from decimal import Decimal
+from typing import Dict, List, Tuple, Union
+from uuid import UUID
+
+# TODO: Use this to convert arbitrary dictionary into its own schema, for W3C TD
+# Python types to Marshmallow fields
+DEFAULT_TYPE_MAPPING = {
+    bool: Boolean,
+    date: Date,
+    datetime: DateTime,
+    Decimal: Decimal,
+    float: Float,
+    int: Integer,
+    str: String,
+    time: Time,
+    timedelta: TimeDelta,
+    UUID: UUID,
+    dict: Dict,
+    Dict: Dict,
+}
+
+# Functions to handle conversion of common Python types into serialisable Python types
+
+
+def ndarray_to_list(o):
+    return o.tolist()
+
+
+def to_int(o):
+    return int(o)
+
+
+def to_float(o):
+    return float(o)
+
+
+def to_string(o):
+    return str(o)
+
+
+# Map of Python type conversions
+DEFAULT_TYPE_CONVERSIONS = {
+    "numpy.ndarray": ndarray_to_list,
+    "numpy.int": to_int,
+    "fractions.Fraction": to_float,
+}
+
+# Use with [x.__module__+"."+x.__name__ for x in inspect.getmro(type(POSSIBLE_MATCHER))]