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

   1 /*
   2  * Sone - ParserFilter.java - Copyright © 2011–2012 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.Writer;
  24 import java.util.ArrayList;
  25 import java.util.List;
  26 import java.util.Map;
  27
  28 import net.pterodactylus.sone.core.Core;
  29 import net.pterodactylus.sone.data.Sone;
  30 import net.pterodactylus.sone.text.FreenetLinkPart;
  31 import net.pterodactylus.sone.text.LinkPart;
  32 import net.pterodactylus.sone.text.Part;
  33 import net.pterodactylus.sone.text.PlainTextPart;
  34 import net.pterodactylus.sone.text.PostPart;
  35 import net.pterodactylus.sone.text.SonePart;
  36 import net.pterodactylus.sone.text.SoneTextParser;
  37 import net.pterodactylus.sone.text.SoneTextParserContext;
  38 import net.pterodactylus.sone.web.page.FreenetRequest;
  39 import net.pterodactylus.util.number.Numbers;
  40 import net.pterodactylus.util.template.Filter;
  41 import net.pterodactylus.util.template.Template;
  42 import net.pterodactylus.util.template.TemplateContext;
  43 import net.pterodactylus.util.template.TemplateContextFactory;
  44 import net.pterodactylus.util.template.TemplateParser;
  45
  46 /**
  47  * Filter that filters a given text through a {@link SoneTextParser}.
  48  *
  49  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  50  */
  51 public class ParserFilter implements Filter {
  52
  53         /** The core. */
  54         private final Core core;
  55
  56         /** The link parser. */
  57         private final SoneTextParser soneTextParser;
  58
  59         /** The template context factory. */
  60         private final TemplateContextFactory templateContextFactory;
  61
  62         /** The template for {@link PlainTextPart}s. */
  63         private final Template plainTextTemplate = TemplateParser.parse(new StringReader("<%text|html>"));
  64
  65         /** The template for {@link FreenetLinkPart}s. */
  66         private final Template linkTemplate = TemplateParser.parse(new StringReader("<a class=\"<%cssClass|html>\" href=\"<%link|html>\" title=\"<%title|html>\"><%text|html></a>"));
  67
  68         /**
  69          * Creates a new filter that runs its input through a {@link SoneTextParser}
  70          * .
  71          *
  72          * @param core
  73          *            The core
  74          * @param templateContextFactory
  75          *            The context factory for rendering the parts
  76          * @param soneTextParser
  77          *            The Sone text parser
  78          */
  79         public ParserFilter(Core core, TemplateContextFactory templateContextFactory, SoneTextParser soneTextParser) {
  80                 this.core = core;
  81                 this.templateContextFactory = templateContextFactory;
  82                 this.soneTextParser = soneTextParser;
  83         }
  84
  85         /**
  86          * {@inheritDoc}
  87          */
  88         @Override
  89         public Object format(TemplateContext templateContext, Object data, Map<String, Object> parameters) {
  90                 String text = String.valueOf(data);
  91                 int length = Numbers.safeParseInteger(parameters.get("length"), Numbers.safeParseInteger(templateContext.get(String.valueOf(parameters.get("length"))), -1));
  92                 int cutOffLength = Numbers.safeParseInteger(parameters.get("cut-off-length"), Numbers.safeParseInteger(templateContext.get(String.valueOf(parameters.get("cut-off-length"))), length));
  93                 Object sone = parameters.get("sone");
  94                 if (sone instanceof String) {
  95                         sone = core.getSone((String) sone, false);
  96                 }
  97                 FreenetRequest request = (FreenetRequest) templateContext.get("request");
  98                 SoneTextParserContext context = new SoneTextParserContext(request, (Sone) sone);
  99                 StringWriter parsedTextWriter = new StringWriter();
 100                 try {
 101                         Iterable<Part> parts = soneTextParser.parse(context, new StringReader(text));
 102                         if (length > -1) {
 103                                 int allPartsLength = 0;
 104                                 List<Part> shortenedParts = new ArrayList<Part>();
 105                                 for (Part part : parts) {
 106                                         if (part instanceof PlainTextPart) {
 107                                                 String longText = ((PlainTextPart) part).getText();
 108                                                 if (allPartsLength < cutOffLength) {
 109                                                         if ((allPartsLength + longText.length()) > cutOffLength) {
 110                                                                 shortenedParts.add(new PlainTextPart(longText.substring(0, cutOffLength - allPartsLength) + "…"));
 111                                                         } else {
 112                                                                 shortenedParts.add(part);
 113                                                         }
 114                                                 }
 115                                                 allPartsLength += longText.length();
 116                                         } else if (part instanceof LinkPart) {
 117                                                 if (allPartsLength < cutOffLength) {
 118                                                         shortenedParts.add(part);
 119                                                 }
 120                                                 allPartsLength += ((LinkPart) part).getText().length();
 121                                         } else {
 122                                                 if (allPartsLength < cutOffLength) {
 123                                                         shortenedParts.add(part);
 124                                                 }
 125                                         }
 126                                 }
 127                                 if (allPartsLength >= length) {
 128                                         parts = shortenedParts;
 129                                 }
 130                         }
 131                         render(parsedTextWriter, parts);
 132                 } catch (IOException ioe1) {
 133                         /* no exceptions in a StringReader or StringWriter, ignore. */
 134                 }
 135                 return parsedTextWriter.toString();
 136         }
 137
 138         //
 139         // PRIVATE METHODS
 140         //
 141
 142         /**
 143          * Renders the given parts.
 144          *
 145          * @param writer
 146          *            The writer to render the parts to
 147          * @param parts
 148          *            The parts to render
 149          */
 150         private void render(Writer writer, Iterable<Part> parts) {
 151                 for (Part part : parts) {
 152                         render(writer, part);
 153                 }
 154         }
 155
 156         /**
 157          * Renders the given part.
 158          *
 159          * @param writer
 160          *            The writer to render the part to
 161          * @param part
 162          *            The part to render
 163          */
 164         @SuppressWarnings("unchecked")
 165         private void render(Writer writer, Part part) {
 166                 if (part instanceof PlainTextPart) {
 167                         render(writer, (PlainTextPart) part);
 168                 } else if (part instanceof FreenetLinkPart) {
 169                         render(writer, (FreenetLinkPart) part);
 170                 } else if (part instanceof LinkPart) {
 171                         render(writer, (LinkPart) part);
 172                 } else if (part instanceof SonePart) {
 173                         render(writer, (SonePart) part);
 174                 } else if (part instanceof PostPart) {
 175                         render(writer, (PostPart) part);
 176                 } else if (part instanceof Iterable<?>) {
 177                         render(writer, (Iterable<Part>) part);
 178                 }
 179         }
 180
 181         /**
 182          * Renders the given plain-text part.
 183          *
 184          * @param writer
 185          *            The writer to render the part to
 186          * @param plainTextPart
 187          *            The part to render
 188          */
 189         private void render(Writer writer, PlainTextPart plainTextPart) {
 190                 TemplateContext templateContext = templateContextFactory.createTemplateContext();
 191                 templateContext.set("text", plainTextPart.getText());
 192                 plainTextTemplate.render(templateContext, writer);
 193         }
 194
 195         /**
 196          * Renders the given freenet link part.
 197          *
 198          * @param writer
 199          *            The writer to render the part to
 200          * @param freenetLinkPart
 201          *            The part to render
 202          */
 203         private void render(Writer writer, FreenetLinkPart freenetLinkPart) {
 204                 renderLink(writer, "/" + freenetLinkPart.getLink(), freenetLinkPart.getText(), freenetLinkPart.getTitle(), freenetLinkPart.isTrusted() ? "freenet-trusted" : "freenet");
 205         }
 206
 207         /**
 208          * Renders the given link part.
 209          *
 210          * @param writer
 211          *            The writer to render the part to
 212          * @param linkPart
 213          *            The part to render
 214          */
 215         private void render(Writer writer, LinkPart linkPart) {
 216                 renderLink(writer, "/?_CHECKED_HTTP_=" + linkPart.getLink(), linkPart.getText(), linkPart.getTitle(), "internet");
 217         }
 218
 219         /**
 220          * Renders the given Sone part.
 221          *
 222          * @param writer
 223          *            The writer to render the part to
 224          * @param sonePart
 225          *            The part to render
 226          */
 227         private void render(Writer writer, SonePart sonePart) {
 228                 if ((sonePart.getSone() != null) && (sonePart.getSone().getName() != null)) {
 229                         renderLink(writer, "viewSone.html?sone=" + sonePart.getSone().getId(), SoneAccessor.getNiceName(sonePart.getSone()), SoneAccessor.getNiceName(sonePart.getSone()), "in-sone");
 230                 } else {
 231                         renderLink(writer, "/WebOfTrust/ShowIdentity?id=" + sonePart.getSone().getId(), sonePart.getSone().getId(), sonePart.getSone().getId(), "in-sone");
 232                 }
 233         }
 234
 235         /**
 236          * Renders the given post part.
 237          *
 238          * @param writer
 239          *            The writer to render the part to
 240          * @param postPart
 241          *            The part to render
 242          */
 243         private void render(Writer writer, PostPart postPart) {
 244                 renderLink(writer, "viewPost.html?post=" + postPart.getPost().getId(), getExcerpt(postPart.getPost().getText(), 20), SoneAccessor.getNiceName(postPart.getPost().getSone()), "in-sone");
 245         }
 246
 247         /**
 248          * Renders the given link.
 249          *
 250          * @param writer
 251          *            The writer to render the link to
 252          * @param link
 253          *            The link to render
 254          * @param text
 255          *            The text of the link
 256          * @param title
 257          *            The title of the link
 258          * @param cssClass
 259          *            The CSS class of the link
 260          */
 261         private void renderLink(Writer writer, String link, String text, String title, String cssClass) {
 262                 TemplateContext templateContext = templateContextFactory.createTemplateContext();
 263                 templateContext.set("cssClass", cssClass);
 264                 templateContext.set("link", link);
 265                 templateContext.set("text", text);
 266                 templateContext.set("title", title);
 267                 linkTemplate.render(templateContext, writer);
 268         }
 269
 270         //
 271         // STATIC METHODS
 272         //
 273
 274         /**
 275          * Returns up to {@code length} characters from the given text, appending
 276          * “…” if the text is longer.
 277          *
 278          * @param text
 279          *            The text to get an excerpt from
 280          * @param length
 281          *            The maximum length of the excerpt (without the ellipsis)
 282          * @return The excerpt of the text
 283          */
 284         private static String getExcerpt(String text, int length) {
 285                 String filteredText = text.replaceAll("(\r\n)+", "\r\n").replaceAll("\n+", "\n").replace("\r\n", " ").replace('\n', ' ');
 286                 if (filteredText.length() > length) {
 287                         return filteredText.substring(0, length) + "…";
 288                 }
 289                 return filteredText;
 290         }
 291
 292 }