add xlink fix in laser_check

extensions/fablabchemnitz/laser_check/laser_check.py

@@ -13,6 +13,7 @@ from collections import Counter
 from PIL import Image
 from io import BytesIO
 import base64
+import urllib.request as urllib
 
 class LaserCheck(inkex.EffectExtension):
     
@@ -36,6 +37,30 @@ class LaserCheck(inkex.EffectExtension):
     - output time/cost estimations per stroke color
     '''
 
+    def checkImagePath(self, node):
+        """Embed the data of the selected Image Tag element"""
+        xlink = node.get('xlink:href')
+        if xlink and xlink[:5] == 'data:':
+            # No need, data alread embedded
+            return
+
+        url = urllib.urlparse(xlink)
+        href = urllib.url2pathname(url.path)
+
+        # Primary location always the filename itself.
+        path = self.absolute_href(href or '')
+
+        # Backup directory where we can find the image
+        if not os.path.isfile(path):
+            path = node.get('sodipodi:absref', path)
+
+        if not os.path.isfile(path):
+            inkex.errormsg('File not found "{}". Unable to embed image.').format(path)
+            return
+
+        if (os.path.isfile(path)):
+            return path
+    
     def add_arguments(self, pars):
         pars.add_argument('--tab')
         
@@ -482,10 +507,13 @@ class LaserCheck(inkex.EffectExtension):
             malformedScales = []
             maxDPIhits = []
             minDPIhits = []
+            
             for image in images:
                 inkex.utils.debug("image id={}".format(image.get('id')))
                 
-                image_string = image.get('{http://www.w3.org/1999/xlink}href')
+                self.path = self.checkImagePath(image)  # This also ensures the file exists
+                if self.path is None:  # check if image is embedded or linked
+                    image_string = node.get('{http://www.w3.org/1999/xlink}href')
                     # find comma position
                     i = 0
                     while i < 40:
@@ -493,6 +521,10 @@ class LaserCheck(inkex.EffectExtension):
                             break
                         i = i + 1
                     img = Image.open(BytesIO(base64.b64decode(image_string[i + 1:len(image_string)])))
+                else:
+                    img = Image.open(self.path)
+        
+                if img:
                     img_w = img.getbbox()[2]
                     img_h = img.getbbox()[3]
                     if image.get('width') is None: