json convenience functions

CHANGELOG.md

@@ -11,13 +11,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * Added `remap_values` to `compas_utilities`.
 * Added `compas.datastructures.mesh_slice_plane`.
+* Added `compas.json_dump`, `compas.json_dumps`, `compas.json_load`, `compas.json_loads`.
 
 ### Changed
 
 * Fixed bug in `compas.datastructures.Network.delete_node`.
 * Fixed bug in `compas.datastructures.Network.delete_edge`.
 * Fixed bug in select functions for individual objects in `compas_rhino.utilities`.
 * Fixed bug in `compas.datastructures.mesh_merge_faces`.
+* changed base of `compas.geometry.Transformation` to `compas.base.Base`.
 
 ### Removed
 

src/compas/__init__.py

@@ -28,6 +28,7 @@
 import decimal
 
 import compas._os
+from compas._json import json_dump, json_dumps, json_load, json_loads
 
 
 __author__ = 'Tom Van Mele and many others (see AUTHORS.md)'
@@ -72,7 +73,11 @@
     pass
 
 
-__all__ = ['WINDOWS', 'LINUX', 'MONO', 'IPY', 'RHINO', 'BLENDER', 'set_precision', 'get']
+__all__ = [
+    'WINDOWS', 'LINUX', 'MONO', 'IPY', 'RHINO', 'BLENDER',
+    'set_precision',
+    'get',
+    'json_dump', 'json_load', 'json_dumps', 'json_loads']
 
 
 def is_windows():

src/compas/_json.py

@@ -0,0 +1,137 @@
+from __future__ import print_function
+from __future__ import absolute_import
+from __future__ import division
+
+import json
+from compas.utilities import DataEncoder
+from compas.utilities import DataDecoder
+
+
+__all__ = [
+    'json_dump',
+    'json_dumps',
+    'json_load',
+    'json_loads'
+]
+
+
+def json_dump(data, fp):
+    """Write a collection of COMPAS object data to a JSON file.
+
+    Parameters
+    ----------
+    data : any
+        Any JSON serializable object.
+        This includes any (combination of) COMPAS object(s).
+    fp : file-like object or path
+        A writeable file-like object or the path to a file.
+
+    Returns
+    -------
+    None
+
+    Examples
+    --------
+    >>> import compas
+    >>> from compas.geometry import Point, Vector
+    >>> data1 = [Point(0, 0, 0), Vector(0, 0, 0)]
+    >>> compas.json_dump(data1, 'data.json')
+    >>> data2 = compas.json_load('data.json')
+    >>> data1 == data2
+    True
+    """
+    if hasattr(fp, 'write'):
+        return json.dump(data, fp, cls=DataEncoder)
+    with open(fp, 'w') as fp:
+        return json.dump(data, fp, cls=DataEncoder)
+
+
+def json_dumps(data):
+    """Write a collection of COMPAS objects to a JSON string.
+
+    Parameters
+    ----------
+    data : any
+        Any JSON serializable object.
+        This includes any (combination of) COMPAS object(s).
+
+    Returns
+    -------
+    str
+
+    Examples
+    --------
+    >>> import compas
+    >>> from compas.geometry import Point, Vector
+    >>> data1 = [Point(0, 0, 0), Vector(0, 0, 0)]
+    >>> s = compas.json_dumps(data1)
+    >>> data2 compas.json_loads(s)
+    >>> data1 == data2
+    True
+    """
+    return json.dumps(data, cls=DataEncoder)
+
+
+def json_load(fp):
+    """Read COMPAS object data from a JSON file.
+
+    Parameters
+    ----------
+    fp : file-like object or path
+        A writeable file-like object or the path to a file.
+
+    Returns
+    -------
+    data
+        The (COMPAS) data contained in the file.
+
+    Examples
+    --------
+    >>> import compas
+    >>> from compas.geometry import Point, Vector
+    >>> data1 = [Point(0, 0, 0), Vector(0, 0, 0)]
+    >>> compas.json_dump(data1, 'data.json')
+    >>> data2 = compas.json_load('data.json')
+    >>> data1 == data2
+    True
+    """
+    if hasattr(fp, 'read'):
+        return json.load(fp, cls=DataDecoder)
+    with open(fp, 'r') as fp:
+        return json.load(fp, cls=DataDecoder)
+
+
+def json_loads(s):
+    """Read COMPAS object data from a JSON string.
+
+    Parameters
+    ----------
+    s : str
+        A JSON data string.
+
+    Returns
+    -------
+    data
+        The (COMPAS) data contained in the string.
+
+    Examples
+    --------
+    >>> import compas
+    >>> from compas.geometry import Point, Vector
+    >>> data1 = [Point(0, 0, 0), Vector(0, 0, 0)]
+    >>> s = compas.json_dumps(data1)
+    >>> data2 = compas.json_loads()
+    >>> data1 == data2
+    True
+    """
+    return json.loads(s, cls=DataDecoder)
+
+
+# ==============================================================================
+# Main
+# ==============================================================================
+
+if __name__ == '__main__':
+    import doctest
+
+    doctest.testmod(globs=globals())

src/compas/geometry/transformations/transformation.py

@@ -12,6 +12,8 @@
 """
 import math
 
+from compas.base import Base
+
 from compas.geometry import multiply_matrices
 from compas.geometry import transpose_matrix
 
@@ -29,7 +31,7 @@
 __all__ = ['Transformation']
 
 
-class Transformation(object):
+class Transformation(Base):
     """The ``Transformation`` represents a 4x4 transformation matrix.
 
     It is the base class for transformations like :class:`Rotation`,
@@ -60,6 +62,8 @@ class Transformation(object):
     def __init__(self, matrix=None):
         """Construct a transformation from a 4x4 transformation matrix.
         """
+        super(Transformation, self).__init__()
+
         if not matrix:
             matrix = identity_matrix(4)
         self.matrix = matrix

src/compas/utilities/encoders.py

@@ -52,8 +52,12 @@ class DataEncoder(json.JSONEncoder):
     def default(self, o):
         if hasattr(o, 'to_data'):
             value = o.to_data()
+            if hasattr(o, 'dtype'):
+                dtype = o.dtype
+            else:
+                dtype = "{}/{}".format(".".join(o.__class__.__module__.split(".")[:-1]), o.__class__.__name__)
             return {
-                'dtype': "{}/{}".format(".".join(o.__class__.__module__.split(".")[:-1]), o.__class__.__name__),
+                'dtype': dtype,
                 'value': value
             }
 

tests/compas/test_json.py

@@ -0,0 +1,56 @@
+import compas
+
+from compas.geometry import Point, Vector, Frame
+from compas.geometry import Box
+from compas.geometry import Transformation
+
+from compas.datastructures import Mesh
+
+
+def test_json_native():
+    before = [[], (), {}, '', 1, 1.0, True, None]
+    after = compas.json_loads(compas.json_dumps(before))
+    assert after == [[], [], {}, '', 1, 1.0, True, None]
+
+
+if not compas.IPY:
+    import numpy as np
+
+    def test_json_numpy():
+        before = [np.array([1, 2, 3]), np.array([1.0, 2.0, 3.0]), np.float64(1.0), np.int32(1)]
+        after = compas.json_loads(compas.json_dumps(before))
+        assert after == [[1, 2, 3], [1.0, 2.0, 3.0], 1.0, 1]
+
+
+def test_json_primitive():
+    before = Point(0, 0, 0)
+    after = compas.json_loads(compas.json_dumps(before))
+    assert before.dtype == after.dtype
+    assert all(a == b for a, b in zip(before, after))
+
+
+def test_json_shape():
+    before = Box(Frame(Point(0, 0, 0), Vector(1, 0, 0), Vector(0, 1, 0)), 1, 1, 1)
+    after = compas.json_loads(compas.json_dumps(before))
+    assert before.dtype == after.dtype
+    assert all(a == b for a, b in zip(before.vertices, after.vertices))
+
+
+def test_json_xform():
+    before = Transformation.from_frame_to_frame(Frame.worldXY(), Frame.worldXY())
+    after = compas.json_loads(compas.json_dumps(before))
+    assert before.dtype == after.dtype
+    assert all(a == b for a, b in zip(before, after))
+
+
+def test_json_mesh():
+    before = Mesh.from_vertices_and_faces([[0, 0, 0], [1, 0, 0], [1, 1, 0], [0, 1, 0]], [[0, 1, 2, 3]])
+    after = compas.json_loads(compas.json_dumps(before))
+    assert before.dtype == after.dtype
+    assert all(before.has_vertex(vertex) for vertex in after.vertices())
+    assert all(after.has_vertex(vertex) for vertex in before.vertices())
+    assert all(before.has_face(face) for face in after.faces())
+    assert all(after.has_face(face) for face in before.faces())
+    assert all(before.has_edge(edge) for edge in after.edges())
+    assert all(after.has_edge(edge) for edge in before.edges())
+    assert all(before.face_vertices(a) == after.face_vertices(b) for a, b in zip(before.faces(), after.faces()))