ease up and more stable reload drawing

extensions/fablabchemnitz/reload/reload.py

@@ -5,28 +5,45 @@ from lxml import etree
 
 class Reload(inkex.EffectExtension):
 
+    '''
+        This extension gets the current doc path and reads it as doc
+        Then we clear the recent document from all items except basic stuff like root (svg:svg), defs and namedview
+        finally we overwrite all attributes from svg:svg, defs and namedview to the recent
+    '''
+
     def effect(self):
         currentDoc = self.document_path()
         if currentDoc == "":
             self.msg("Your document is not saved as a permanent file yet. Cannot reload.")
             exit(1)
+        
+        originalRoot = self.document.getroot()   
+        originalNamedview = self.svg.namedview
+        originalDefs = originalRoot.find("{http://www.w3.org/2000/svg}defs")
+        originalRoot.clear() #drop all children and attributes from root
+
         stream = open(self.document_path(), 'r')
         p = etree.XMLParser(huge_tree=True)
         doc = etree.parse(stream, parser=etree.XMLParser(huge_tree=True))
         stream.close()
-        root = self.document.getroot()
-        kept = [] #required. if we delete them directly without adding new defs or namedview, inkscape will crash
-        for node in self.document.xpath('//*', namespaces=inkex.NSS):
-            if node.TAG not in ('svg', 'defs', 'namedview'):
-                node.delete()
-            elif node.TAG in ('defs', 'namedview'): #except 'svg'
-                kept.append(node)
+      
+        copyRoot = doc.getroot()
+        copyNamedview = copyRoot.find(inkex.addNS('namedview', 'sodipodi'))
+        copyDefs = copyRoot.find("{http://www.w3.org/2000/svg}defs")
+        for child in copyRoot.getchildren():
+            originalRoot.append(child)
         
-        children = doc.getroot().getchildren()
-        for child in children:
-           root.append(child)
-        for k in kept:
-            k.delete()
-    
+        #update all attributes in originalSVG
+        for copyAttrib in copyRoot.attrib:
+            originalRoot.attrib[copyAttrib] = copyRoot.attrib[copyAttrib]
+
+        #update all attributes in originalNamedview
+        for copyAttrib in copyNamedview.attrib:
+            originalNamedview.attrib[copyAttrib] = copyNamedview.attrib[copyAttrib]
+               
+        #update all attributes in originalDefs
+        for copyAttrib in copyDefs.attrib:
+            originalDefs.attrib[copyAttrib] = copyDefs.attrib[copyAttrib]
+
 if __name__ == '__main__':
     Reload().run()