Filters/FilterSvg.cs

   1 //
   2 // FilterSVG.cs
   3 //
   4 // Copyright (C) 2006 Alexander Macdonald <alex@alexmac.cc>
   5 //
   6
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining a
   9 // copy of this software and associated documentation files (the "Software"),
  10 // to deal in the Software without restriction, including without limitation
  11 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12 // and/or sell copies of the Software, and to permit persons to whom the
  13 // Software is furnished to do so, subject to the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be included in
  16 // all copies or substantial portions of the Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24 // DEALINGS IN THE SOFTWARE.
  25 //
  26
  27 using System;
  28 using System.IO;
  29 using System.Xml;
  30 using System.Text;
  31
  32 using Beagle.Util;
  33 using Beagle.Daemon;
  34
  35 namespace Beagle.Filters {
  36         public class FilterSvg : Beagle.Daemon.Filter {
  37                 private StringBuilder sb = new StringBuilder ();
  38
  39                 // List of keys that should be ignored when adding to content.
  40                 // For example, dc:format is the mime type, so it's not interesting text.
  41                 static private string [] ignore_strings = { "format"};
  42
  43                 static private string dcnamespace = "http://purl.org/dc/elements/1.1/";
  44
  45                 public FilterSvg ()
  46                 {
  47                         AddSupportedFlavor (FilterFlavor.NewFromMimeType ("image/svg+xml"));
  48                         AddSupportedFlavor (FilterFlavor.NewFromExtension (".svg"));
  49                 }
  50
  51                 override protected void DoPullProperties ()
  52                 {
  53                         XmlTextReader reader = new XmlTextReader (Stream);
  54                         reader.XmlResolver = null;
  55
  56                         string current_tag_name = "";
  57                         bool grab_property = false;
  58                         bool grab_text = false;
  59
  60                         try {
  61                                 while (reader.Read ()) {
  62                                         switch (reader.NodeType) {
  63                                         case XmlNodeType.Element:
  64                                                 if (grab_text)
  65                                                         break;
  66                                                 if (reader.IsEmptyElement)
  67                                                         break;
  68
  69                                                 if (ArrayFu.IndexOfString (ignore_strings, reader.LocalName) != -1)
  70                                                         break;
  71                                                 else if (reader.LocalName == "title") {
  72                                                         grab_property = true;
  73                                                         current_tag_name = "title";
  74                                                 } else if (reader.LocalName == "desc") {
  75                                                         grab_property = true;
  76                                                         current_tag_name = "description";
  77                                                 } else if (reader.LocalName == "text") {
  78                                                         grab_text = true;
  79                                                         current_tag_name = "text";
  80                                                 } else if (reader.LocalName == "RDF") {
  81                                                         PullRdfProperties (reader, reader.Depth);
  82                                                 }
  83                                                 break;
  84
  85                                         case XmlNodeType.Text:
  86                                                 if (grab_property)
  87                                                         AddProperty (Property.New ("dc:" + current_tag_name , reader.Value));
  88                                                 else if (grab_text) {
  89                                                         sb.Append (reader.Value);
  90                                                 }
  91                                                 break;
  92
  93                                         case XmlNodeType.Comment:
  94                                                 AppendText (reader.Value.Trim ());
  95                                                 AppendStructuralBreak ();
  96                                                 break;
  97
  98                                         case XmlNodeType.EndElement:
  99                                                 if (reader.LocalName != current_tag_name)
 100                                                         break;
 101
 102                                                 if(grab_text) {
 103                                                         AppendText (sb.ToString());
 104                                                         AppendStructuralBreak ();
 105                                                 }
 106
 107                                                 grab_text = grab_property = false;
 108                                                 break;
 109                                         }
 110                                 }
 111
 112                                 Finished ();
 113                         } catch (System.Xml.XmlException e) {
 114                                 Logger.Log.Error ("Error parsing xml file {0}", FileInfo.FullName);
 115                                 Logger.Log.Debug (e);
 116                                 Error ();
 117                         }
 118                 }
 119
 120                 protected void PullRdfProperties (XmlTextReader reader, int depth)
 121                 {
 122                         string current_tag_name = "";
 123                         bool grab_text = false;
 124                         bool grab_date = false;
 125
 126                         try {
 127                                 while (reader.Read ()) {
 128                                         if (depth == reader.Depth)
 129                                                 return;
 130
 131                                         switch (reader.NodeType) {
 132                                         case XmlNodeType.Element:
 133                                                 if (grab_text)
 134                                                         break;
 135
 136                                                 if (reader.IsEmptyElement)
 137                                                         break;
 138
 139                                                 if (ArrayFu.IndexOfString (ignore_strings, reader.LocalName) != -1)
 140                                                         break;
 141                                                 else if (reader.NamespaceURI == dcnamespace) {
 142                                                         if (reader.LocalName == "date")
 143                                                                 grab_date = true;
 144                                                         else
 145                                                                 grab_text = true;
 146                                                 }
 147
 148                                                 current_tag_name = reader.LocalName;
 149                                                 break;
 150
 151                                         case XmlNodeType.Text:
 152                                                 if (grab_text)
 153                                                         AddProperty (Property.New ("dc:" + current_tag_name, reader.Value));
 154                                                 else if (grab_date) {
 155                                                         try {
 156                                                                 AddProperty (Property.NewDate ("dc:date", System.Convert.ToDateTime (reader.Value.Trim())));
 157                                                         } catch (FormatException) {
 158                                                                 AddProperty (Property.New ("dc:date", reader.Value));
 159                                                         }
 160                                                 }
 161                                                 break;
 162
 163                                         case XmlNodeType.EndElement:
 164                                                 if(reader.LocalName == current_tag_name)
 165                                                         grab_text = grab_date = false;
 166                                                 break;
 167                                         }
 168                                 }
 169                         } catch (System.Xml.XmlException e) {
 170                                 Logger.Log.Error ("error parsing embedded RDF {0}", FileInfo.FullName);
 171                                 Logger.Log.Debug (e);
 172                                 Error ();
 173                         }
 174                 }
 175         }
 176 }