Merge pull request #176 from FlyingSamson/read-svg-from-file-like-obj

Support reading of SVGs from strings and file-like objects

svgpathtools/__init__.py

@@ -17,6 +17,6 @@ from .document import (Document, CONVERSIONS, CONVERT_ONLY_PATHS,
 from .svg_io_sax import SaxDocument
 
 try:
-    from .svg_to_paths import svg2paths, svg2paths2
+    from .svg_to_paths import svg2paths, svg2paths2, svgstr2paths
 except ImportError:
     pass

svgpathtools/document.py

@@ -41,6 +41,7 @@ import xml.etree.ElementTree as etree
 from xml.etree.ElementTree import Element, SubElement, register_namespace
 from xml.dom.minidom import parseString
 import warnings
+from io import StringIO
 from tempfile import gettempdir
 from time import time
 
@@ -235,13 +236,19 @@ class Document:
         The output Path objects will be transformed based on their parent groups.
         
         Args:
-            filepath (str): The filepath of the DOM-style object.
+            filepath (str or file-like): The filepath of the
+                DOM-style object or a file-like object containing it.
         """
+        self.original_filepath = None
 
-        # remember location of original svg file
+        # strings are interpreted as file location everything else is treated as
-        self.original_filepath = filepath
+        # file-like object and passed to the xml parser directly
-        if filepath is not None and os.path.dirname(filepath) == '':
+        if isinstance(filepath, str):
-            self.original_filepath = os.path.join(os.getcwd(), filepath)
+            # remember location of original svg file if any
+            self.original_filepath = filepath
+            if os.path.dirname(filepath) == '':
+                self.original_filepath = os.path.join(
+                    os.getcwd(), filepath)
 
         if filepath is None:
             self.tree = etree.ElementTree(Element('svg'))
@@ -251,6 +258,16 @@ class Document:
 
         self.root = self.tree.getroot()
 
+    @classmethod
+    def from_svg_string(cls, svg_string):
+        """Factory method for creating a document from a string holding a svg
+        object
+        """
+        # wrap string into StringIO object
+        svg_file_obj = StringIO(svg_string)
+        # create document from file object
+        return Document(svg_file_obj)
+
     def paths(self, group_filter=lambda x: True,
               path_filter=lambda x: True, path_conversions=CONVERSIONS):
         """Returns a list of all paths in the document.

svgpathtools/svg_to_paths.py

@@ -5,6 +5,7 @@ The main tool being the svg2paths() function."""
 from __future__ import division, absolute_import, print_function
 from xml.dom.minidom import parse
 from os import path as os_path, getcwd
+from io import StringIO
 import re
 
 # Internal dependencies
@@ -144,7 +145,9 @@ def svg2paths(svg_file_location,
     SVG Path, Line, Polyline, Polygon, Circle, and Ellipse elements.
 
     Args:
-        svg_file_location (string): the location of the svg file
+        svg_file_location (string or file-like object): the location of the
+            svg file on disk or a file-like object containing the content of a
+            svg file
         return_svg_attributes (bool): Set to True and a dictionary of
             svg-attributes will be extracted and returned.  See also the 
             `svg2paths2()` function.
@@ -168,8 +171,12 @@ def svg2paths(svg_file_location,
         list: The list of corresponding path attribute dictionaries.
         dict (optional): A dictionary of svg-attributes (see `svg2paths2()`).
     """
-    if os_path.dirname(svg_file_location) == '':
+    # strings are interpreted as file location everything else is treated as
-        svg_file_location = os_path.join(getcwd(), svg_file_location)
+    # file-like object and passed to the xml parser directly
+    if isinstance(svg_file_location, str):
+        if os_path.dirname(svg_file_location) == '':
+            svg_file_location = os_path.join(
+                getcwd(), svg_file_location)
 
     doc = parse(svg_file_location)
 
@@ -249,3 +256,26 @@ def svg2paths2(svg_file_location,
                      convert_polylines_to_paths=convert_polylines_to_paths,
                      convert_polygons_to_paths=convert_polygons_to_paths,
                      convert_rectangles_to_paths=convert_rectangles_to_paths)
+
+
+def svgstr2paths(svg_string,
+               return_svg_attributes=False,
+               convert_circles_to_paths=True,
+               convert_ellipses_to_paths=True,
+               convert_lines_to_paths=True,
+               convert_polylines_to_paths=True,
+               convert_polygons_to_paths=True,
+               convert_rectangles_to_paths=True):
+    """Convenience function; identical to svg2paths() except that it takes the
+    svg object as string.  See svg2paths() docstring for more
+    info."""
+    # wrap string into StringIO object
+    svg_file_obj = StringIO(svg_string)
+    return svg2paths(svg_file_location=svg_file_obj,
+                     return_svg_attributes=return_svg_attributes,
+                     convert_circles_to_paths=convert_circles_to_paths,
+                     convert_ellipses_to_paths=convert_ellipses_to_paths,
+                     convert_lines_to_paths=convert_lines_to_paths,
+                     convert_polylines_to_paths=convert_polylines_to_paths,
+                     convert_polygons_to_paths=convert_polygons_to_paths,
+                     convert_rectangles_to_paths=convert_rectangles_to_paths)

test/test_document.py

@@ -0,0 +1,44 @@
+from __future__ import division, absolute_import, print_function
+import unittest
+from svgpathtools import *
+from io import StringIO
+from io import open # overrides build-in open for compatibility with python2
+from os.path import join, dirname
+
+class TestDocument(unittest.TestCase):
+    def test_from_file_path(self):
+        """ Test reading svg from file provided as path """
+        doc = Document(join(dirname(__file__), 'polygons.svg'))
+
+        self.assertEqual(len(doc.paths()), 2)
+
+    def test_from_file_object(self):
+        """ Test reading svg from file object that has already been opened """
+        with open(join(dirname(__file__), 'polygons.svg'), 'r') as file:
+            doc = Document(file)
+
+            self.assertEqual(len(doc.paths()), 2)
+
+    def test_from_stringio(self):
+        """ Test reading svg object contained in a StringIO object """
+        with open(join(dirname(__file__), 'polygons.svg'),
+                  'r', encoding='utf-8') as file:
+            # read entire file into string
+            file_content = file.read()
+            # prepare stringio object
+            file_as_stringio = StringIO(file_content)
+
+            doc = Document(file_as_stringio)
+
+            self.assertEqual(len(doc.paths()), 2)
+
+    def test_from_string(self):
+        """ Test reading svg object contained in a string"""
+        with open(join(dirname(__file__), 'polygons.svg'),
+                  'r', encoding='utf-8') as file:
+            # read entire file into string
+            file_content = file.read()
+
+            doc = Document.from_svg_string(file_content)
+
+            self.assertEqual(len(doc.paths()), 2)

test/test_svg2paths.py

@@ -1,6 +1,8 @@
 from __future__ import division, absolute_import, print_function
 import unittest
 from svgpathtools import *
+from io import StringIO
+from io import open # overrides build-in open for compatibility with python2
 from os.path import join, dirname
 
 from svgpathtools.svg_to_paths import rect2pathd
@@ -57,4 +59,41 @@ class TestSVG2Paths(unittest.TestCase):
         non_rounded = {"x":"10", "y":"10", "width":"100","height":"100"}
         self.assertEqual(rect2pathd(non_rounded), 'M10.0 10.0 L 110.0 10.0 L 110.0 110.0 L 10.0 110.0 z')
         rounded = {"x":"10", "y":"10", "width":"100","height":"100", "rx":"15", "ry": "12"}
-        self.assertEqual(rect2pathd(rounded), "M 25.0 10.0 L 95.0 10.0 A 15.0 12.0 0 0 1 110.0 22.0 L 110.0 98.0 A 15.0 12.0 0 0 1 95.0 110.0 L 25.0 110.0 A 15.0 12.0 0 0 1 10.0 98.0 L 10.0 22.0 A 15.0 12.0 0 0 1 25.0 10.0 z")
+        self.assertEqual(rect2pathd(rounded), "M 25.0 10.0 L 95.0 10.0 A 15.0 12.0 0 0 1 110.0 22.0 L 110.0 98.0 A 15.0 12.0 0 0 1 95.0 110.0 L 25.0 110.0 A 15.0 12.0 0 0 1 10.0 98.0 L 10.0 22.0 A 15.0 12.0 0 0 1 25.0 10.0 z")
+
+    def test_from_file_path(self):
+        """ Test reading svg from file provided as path """
+        paths, _ = svg2paths(join(dirname(__file__), 'polygons.svg'))
+
+        self.assertEqual(len(paths), 2)
+
+    def test_from_file_object(self):
+        """ Test reading svg from file object that has already been opened """
+        with open(join(dirname(__file__), 'polygons.svg'), 'r') as file:
+            paths, _ = svg2paths(file)
+
+            self.assertEqual(len(paths), 2)
+
+    def test_from_stringio(self):
+        """ Test reading svg object contained in a StringIO object """
+        with open(join(dirname(__file__), 'polygons.svg'),
+                  'r', encoding='utf-8') as file:
+            # read entire file into string
+            file_content = file.read()
+            # prepare stringio object
+            file_as_stringio = StringIO(file_content)
+
+            paths, _ = svg2paths(file_as_stringio)
+
+            self.assertEqual(len(paths), 2)
+
+    def test_from_string(self):
+        """ Test reading svg object contained in a string """
+        with open(join(dirname(__file__), 'polygons.svg'),
+                  'r', encoding='utf-8') as file:
+            # read entire file into string
+            file_content = file.read()
+
+            paths, _ = svgstr2paths(file_content)
+
+            self.assertEqual(len(paths), 2)