Cache text conversion of image.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@24495 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/Image.py

@@ -304,13 +304,11 @@ class Image(File, OFSImage):
       return displays
 
 
-  # Conversion API
-  security.declareProtected(Permissions.ModifyPortalContent, 'convert')
-  def convert(self, format, display=None, quality=75, resolution=None, frame=None, **kw):
+  security.declarePrivate('_convertToText')
+  def _convertToText(self, format):
     """
-    Implementation of conversion for PDF files
+    Convert the image to text with portaltransforms
     """
-    if format in ('text', 'txt', 'html', 'base_html', 'stripped-html'):
     mime_type = getToolByName(self, 'mimetypes_registry').\
                                 lookupExtension('name.%s' % format)
     src_mimetype = self.getContentType()
@@ -330,6 +328,18 @@ class Image(File, OFSImage):
     else:
       # text_content is not set, return empty string instead of None
       return mime_type, ''
+
+  # Conversion API
+  security.declareProtected(Permissions.ModifyPortalContent, 'convert')
+  def convert(self, format, display=None, quality=75, resolution=None, frame=None, **kw):
+    """
+    Implementation of conversion for PDF files
+    """
+    if format in ('text', 'txt', 'html', 'base_html', 'stripped-html'):
+      if not self.hasConversion(format=format):
+        mime_type, data = self._convertToText(format)
+        self.setConversion(data, mime=mime_type, format=format)
+      return self.getConversion(format=format)
     image_size = self.getSizeFromImageDisplay(display)
     if (display is not None or resolution is not None or quality != 75 or format != ''\
                             or frame is not None) and image_size: