src/main/java/net/pterodactylus/sone/template/ParserFilter.java

   1 /*
   2  * Sone - ParserFilter.java - Copyright © 2011–2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.sone.template;
  19
  20 import java.io.IOException;
  21 import java.io.StringReader;
  22 import java.io.StringWriter;
  23 import java.io.UnsupportedEncodingException;
  24 import java.io.Writer;
  25 import java.net.URLEncoder;
  26 import java.util.ArrayList;
  27 import java.util.List;
  28 import java.util.Map;
  29
  30 import net.pterodactylus.sone.core.Core;
  31 import net.pterodactylus.sone.data.Sone;
  32 import net.pterodactylus.sone.text.FreenetLinkPart;
  33 import net.pterodactylus.sone.text.LinkPart;
  34 import net.pterodactylus.sone.text.Part;
  35 import net.pterodactylus.sone.text.PlainTextPart;
  36 import net.pterodactylus.sone.text.PostPart;
  37 import net.pterodactylus.sone.text.SonePart;
  38 import net.pterodactylus.sone.text.SoneTextParser;
  39 import net.pterodactylus.sone.text.SoneTextParserContext;
  40 import net.pterodactylus.sone.web.page.FreenetRequest;
  41 import net.pterodactylus.util.number.Numbers;
  42 import net.pterodactylus.util.template.Filter;
  43 import net.pterodactylus.util.template.Template;
  44 import net.pterodactylus.util.template.TemplateContext;
  45 import net.pterodactylus.util.template.TemplateContextFactory;
  46 import net.pterodactylus.util.template.TemplateParser;
  47
  48 /**
  49  * Filter that filters a given text through a {@link SoneTextParser}.
  50  *
  51  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  52  */
  53 public class ParserFilter implements Filter {
  54
  55         /** The core. */
  56         private final Core core;
  57
  58         /** The link parser. */
  59         private final SoneTextParser soneTextParser;
  60
  61         /** The template context factory. */
  62         private final TemplateContextFactory templateContextFactory;
  63
  64         /** The template for {@link PlainTextPart}s. */
  65         private static final Template plainTextTemplate = TemplateParser.parse(new StringReader("<%text|html>"));
  66
  67         /** The template for {@link FreenetLinkPart}s. */
  68         private static final Template linkTemplate = TemplateParser.parse(new StringReader("<a class=\"<%cssClass|html>\" href=\"<%link|html>\" title=\"<%title|html>\"><%text|html></a>"));
  69
  70         /**
  71          * Creates a new filter that runs its input through a {@link SoneTextParser}
  72          * .
  73          *
  74          * @param core
  75          *            The core
  76          * @param templateContextFactory
  77          *            The context factory for rendering the parts
  78          * @param soneTextParser
  79          *            The Sone text parser
  80          */
  81         public ParserFilter(Core core, TemplateContextFactory templateContextFactory, SoneTextParser soneTextParser) {
  82                 this.core = core;
  83                 this.templateContextFactory = templateContextFactory;
  84                 this.soneTextParser = soneTextParser;
  85         }
  86
  87         @Override
  88         public Object format(TemplateContext templateContext, Object data, Map<String, Object> parameters) {
  89                 String text = String.valueOf(data);
  90                 int length = Numbers.safeParseInteger(parameters.get("length"), Numbers.safeParseInteger(templateContext.get(String.valueOf(parameters.get("length"))), -1));
  91                 int cutOffLength = Numbers.safeParseInteger(parameters.get("cut-off-length"), Numbers.safeParseInteger(templateContext.get(String.valueOf(parameters.get("cut-off-length"))), length));
  92                 Object sone = parameters.get("sone");
  93                 if (sone instanceof String) {
  94                         sone = core.getSone((String) sone).orNull();
  95                 }
  96                 FreenetRequest request = (FreenetRequest) templateContext.get("request");
  97                 SoneTextParserContext context = new SoneTextParserContext(request, (Sone) sone);
  98                 StringWriter parsedTextWriter = new StringWriter();
  99                 try {
 100                         Iterable<Part> parts = soneTextParser.parse(context, new StringReader(text));
 101                         if (length > -1) {
 102                                 int allPartsLength = 0;
 103                                 List<Part> shortenedParts = new ArrayList<Part>();
 104                                 for (Part part : parts) {
 105                                         if (part instanceof PlainTextPart) {
 106                                                 String longText = ((PlainTextPart) part).getText();
 107                                                 if (allPartsLength < cutOffLength) {
 108                                                         if ((allPartsLength + longText.length()) > cutOffLength) {
 109                                                                 shortenedParts.add(new PlainTextPart(longText.substring(0, cutOffLength - allPartsLength) + "…"));
 110                                                         } else {
 111                                                                 shortenedParts.add(part);
 112                                                         }
 113                                                 }
 114                                                 allPartsLength += longText.length();
 115                                         } else if (part instanceof LinkPart) {
 116                                                 if (allPartsLength < cutOffLength) {
 117                                                         shortenedParts.add(part);
 118                                                 }
 119                                                 allPartsLength += ((LinkPart) part).getText().length();
 120                                         } else {
 121                                                 if (allPartsLength < cutOffLength) {
 122                                                         shortenedParts.add(part);
 123                                                 }
 124                                         }
 125                                 }
 126                                 if (allPartsLength >= length) {
 127                                         parts = shortenedParts;
 128                                 }
 129                         }
 130                         render(parsedTextWriter, parts);
 131                 } catch (IOException ioe1) {
 132                         /* no exceptions in a StringReader or StringWriter, ignore. */
 133                 }
 134                 return parsedTextWriter.toString();
 135         }
 136
 137         //
 138         // PRIVATE METHODS
 139         //
 140
 141         /**
 142          * Renders the given parts.
 143          *
 144          * @param writer
 145          *            The writer to render the parts to
 146          * @param parts
 147          *            The parts to render
 148          */
 149         private void render(Writer writer, Iterable<Part> parts) {
 150                 for (Part part : parts) {
 151                         render(writer, part);
 152                 }
 153         }
 154
 155         /**
 156          * Renders the given part.
 157          *
 158          * @param writer
 159          *            The writer to render the part to
 160          * @param part
 161          *            The part to render
 162          */
 163         @SuppressWarnings("unchecked")
 164         private void render(Writer writer, Part part) {
 165                 if (part instanceof PlainTextPart) {
 166                         render(writer, (PlainTextPart) part);
 167                 } else if (part instanceof FreenetLinkPart) {
 168                         render(writer, (FreenetLinkPart) part);
 169                 } else if (part instanceof LinkPart) {
 170                         render(writer, (LinkPart) part);
 171                 } else if (part instanceof SonePart) {
 172                         render(writer, (SonePart) part);
 173                 } else if (part instanceof PostPart) {
 174                         render(writer, (PostPart) part);
 175                 } else if (part instanceof Iterable<?>) {
 176                         render(writer, (Iterable<Part>) part);
 177                 }
 178         }
 179
 180         /**
 181          * Renders the given plain-text part.
 182          *
 183          * @param writer
 184          *            The writer to render the part to
 185          * @param plainTextPart
 186          *            The part to render
 187          */
 188         private void render(Writer writer, PlainTextPart plainTextPart) {
 189                 TemplateContext templateContext = templateContextFactory.createTemplateContext();
 190                 templateContext.set("text", plainTextPart.getText());
 191                 plainTextTemplate.render(templateContext, writer);
 192         }
 193
 194         /**
 195          * Renders the given freenet link part.
 196          *
 197          * @param writer
 198          *            The writer to render the part to
 199          * @param freenetLinkPart
 200          *            The part to render
 201          */
 202         private void render(Writer writer, FreenetLinkPart freenetLinkPart) {
 203                 renderLink(writer, "/" + freenetLinkPart.getLink(), freenetLinkPart.getText(), freenetLinkPart.getTitle(), freenetLinkPart.isTrusted() ? "freenet-trusted" : "freenet");
 204         }
 205
 206         /**
 207          * Renders the given link part.
 208          *
 209          * @param writer
 210          *            The writer to render the part to
 211          * @param linkPart
 212          *            The part to render
 213          */
 214         private void render(Writer writer, LinkPart linkPart) {
 215                 try {
 216                         renderLink(writer, "/external-link/?_CHECKED_HTTP_=" + URLEncoder.encode(linkPart.getLink(), "UTF-8"), linkPart.getText(), linkPart.getTitle(), "internet");
 217                 } catch (UnsupportedEncodingException uee1) {
 218                         /* not possible for UTF-8. */
 219                         throw new RuntimeException("The JVM does not support UTF-8 encoding!", uee1);
 220                 }
 221         }
 222
 223         /**
 224          * Renders the given Sone part.
 225          *
 226          * @param writer
 227          *            The writer to render the part to
 228          * @param sonePart
 229          *            The part to render
 230          */
 231         private void render(Writer writer, SonePart sonePart) {
 232                 if ((sonePart.getSone() != null) && (sonePart.getSone().getName() != null)) {
 233                         renderLink(writer, "viewSone.html?sone=" + sonePart.getSone().getId(), SoneAccessor.getNiceName(sonePart.getSone()), SoneAccessor.getNiceName(sonePart.getSone()), "in-sone");
 234                 } else {
 235                         renderLink(writer, "/WebOfTrust/ShowIdentity?id=" + sonePart.getSone().getId(), sonePart.getSone().getId(), sonePart.getSone().getId(), "in-sone");
 236                 }
 237         }
 238
 239         /**
 240          * Renders the given post part.
 241          *
 242          * @param writer
 243          *            The writer to render the part to
 244          * @param postPart
 245          *            The part to render
 246          */
 247         private void render(Writer writer, PostPart postPart) {
 248                 SoneTextParser parser = new SoneTextParser(core.getDatabase());
 249                 SoneTextParserContext parserContext = new SoneTextParserContext(null, postPart.getPost().getSone());
 250                 try {
 251                         Iterable<Part> parts = parser.parse(parserContext, new StringReader(postPart.getPost().getText()));
 252                         StringBuilder excerpt = new StringBuilder();
 253                         for (Part part : parts) {
 254                                 excerpt.append(part.getText());
 255                                 if (excerpt.length() > 20) {
 256                                         int lastSpace = excerpt.lastIndexOf(" ", 20);
 257                                         if (lastSpace > -1) {
 258                                                 excerpt.setLength(lastSpace);
 259                                         } else {
 260                                                 excerpt.setLength(20);
 261                                         }
 262                                         excerpt.append("…");
 263                                         break;
 264                                 }
 265                         }
 266                         renderLink(writer, "viewPost.html?post=" + postPart.getPost().getId(), excerpt.toString(), SoneAccessor.getNiceName(postPart.getPost().getSone()), "in-sone");
 267                 } catch (IOException ioe1) {
 268                         /* StringReader shouldn’t throw. */
 269                 }
 270         }
 271
 272         /**
 273          * Renders the given link.
 274          *
 275          * @param writer
 276          *            The writer to render the link to
 277          * @param link
 278          *            The link to render
 279          * @param text
 280          *            The text of the link
 281          * @param title
 282          *            The title of the link
 283          * @param cssClass
 284          *            The CSS class of the link
 285          */
 286         private void renderLink(Writer writer, String link, String text, String title, String cssClass) {
 287                 TemplateContext templateContext = templateContextFactory.createTemplateContext();
 288                 templateContext.set("cssClass", cssClass);
 289                 templateContext.set("link", link);
 290                 templateContext.set("text", text);
 291                 templateContext.set("title", title);
 292                 linkTemplate.render(templateContext, writer);
 293         }
 294
 295 }