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

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