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.Page.Request;
  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 = -1;
  91                 try {
  92                         length = Integer.parseInt(parameters.get("length"));
  93                 } catch (NumberFormatException nfe1) {
  94                         /* ignore. */
  95                 }
  96                 if ((length == -1) && (parameters.get("length") != null)) {
  97                         try {
  98                                 length = Integer.parseInt(String.valueOf(templateContext.get(parameters.get("length"))));
  99                         } catch (NumberFormatException nfe1) {
 100                                 /* ignore. */
 101                         }
 102                 }
 103                 String soneKey = parameters.get("sone");
 104                 if (soneKey == null) {
 105                         soneKey = "sone";
 106                 }
 107                 Sone sone = (Sone) templateContext.get(soneKey);
 108                 if (sone == null) {
 109                         sone = core.getSone(soneKey, false);
 110                 }
 111                 Request request = (Request) templateContext.get("request");
 112                 SoneTextParserContext context = new SoneTextParserContext(request, sone);
 113                 StringWriter parsedTextWriter = new StringWriter();
 114                 try {
 115                         Iterable<Part> parts = soneTextParser.parse(context, new StringReader(text));
 116                         if (length > -1) {
 117                                 List<Part> shortenedParts = new ArrayList<Part>();
 118                                 for (Part part : parts) {
 119                                         if (part instanceof PlainTextPart) {
 120                                                 String longText = ((PlainTextPart) part).getText();
 121                                                 if (length >= longText.length()) {
 122                                                         shortenedParts.add(part);
 123                                                 } else {
 124                                                         shortenedParts.add(new PlainTextPart(longText.substring(0, length) + "…"));
 125                                                 }
 126                                                 length -= longText.length();
 127                                         } else if (part instanceof LinkPart) {
 128                                                 shortenedParts.add(part);
 129                                                 length -= ((LinkPart) part).getText().length();
 130                                         } else {
 131                                                 shortenedParts.add(part);
 132                                         }
 133                                         if (length <= 0) {
 134                                                 break;
 135                                         }
 136                                 }
 137                                 parts = shortenedParts;
 138                         }
 139                         render(parsedTextWriter, parts);
 140                 } catch (IOException ioe1) {
 141                         /* no exceptions in a StringReader or StringWriter, ignore. */
 142                 }
 143                 return parsedTextWriter.toString();
 144         }
 145
 146         //
 147         // PRIVATE METHODS
 148         //
 149
 150         /**
 151          * Renders the given parts.
 152          *
 153          * @param writer
 154          *            The writer to render the parts to
 155          * @param parts
 156          *            The parts to render
 157          */
 158         private void render(Writer writer, Iterable<Part> parts) {
 159                 for (Part part : parts) {
 160                         render(writer, part);
 161                 }
 162         }
 163
 164         /**
 165          * Renders the given part.
 166          *
 167          * @param writer
 168          *            The writer to render the part to
 169          * @param part
 170          *            The part to render
 171          */
 172         @SuppressWarnings("unchecked")
 173         private void render(Writer writer, Part part) {
 174                 if (part instanceof PlainTextPart) {
 175                         render(writer, (PlainTextPart) part);
 176                 } else if (part instanceof FreenetLinkPart) {
 177                         render(writer, (FreenetLinkPart) part);
 178                 } else if (part instanceof LinkPart) {
 179                         render(writer, (LinkPart) part);
 180                 } else if (part instanceof SonePart) {
 181                         render(writer, (SonePart) part);
 182                 } else if (part instanceof PostPart) {
 183                         render(writer, (PostPart) part);
 184                 } else if (part instanceof Iterable<?>) {
 185                         render(writer, (Iterable<Part>) part);
 186                 }
 187         }
 188
 189         /**
 190          * Renders the given plain-text part.
 191          *
 192          * @param writer
 193          *            The writer to render the part to
 194          * @param plainTextPart
 195          *            The part to render
 196          */
 197         private void render(Writer writer, PlainTextPart plainTextPart) {
 198                 TemplateContext templateContext = templateContextFactory.createTemplateContext();
 199                 templateContext.set("text", plainTextPart.getText());
 200                 plainTextTemplate.render(templateContext, writer);
 201         }
 202
 203         /**
 204          * Renders the given freenet link part.
 205          *
 206          * @param writer
 207          *            The writer to render the part to
 208          * @param freenetLinkPart
 209          *            The part to render
 210          */
 211         private void render(Writer writer, FreenetLinkPart freenetLinkPart) {
 212                 renderLink(writer, "/" + freenetLinkPart.getLink(), freenetLinkPart.getText(), freenetLinkPart.getTitle(), freenetLinkPart.isTrusted() ? "freenet-trusted" : "freenet");
 213         }
 214
 215         /**
 216          * Renders the given link part.
 217          *
 218          * @param writer
 219          *            The writer to render the part to
 220          * @param linkPart
 221          *            The part to render
 222          */
 223         private void render(Writer writer, LinkPart linkPart) {
 224                 renderLink(writer, "/?_CHECKED_HTTP_=" + linkPart.getLink(), linkPart.getText(), linkPart.getTitle(), "internet");
 225         }
 226
 227         /**
 228          * Renders the given Sone part.
 229          *
 230          * @param writer
 231          *            The writer to render the part to
 232          * @param sonePart
 233          *            The part to render
 234          */
 235         private void render(Writer writer, SonePart sonePart) {
 236                 renderLink(writer, "viewSone.html?sone=" + sonePart.getSone().getId(), SoneAccessor.getNiceName(sonePart.getSone()), SoneAccessor.getNiceName(sonePart.getSone()), "in-sone");
 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                 renderLink(writer, "viewPost.html?post=" + postPart.getPost().getId(), getExcerpt(postPart.getPost().getText(), 20), SoneAccessor.getNiceName(postPart.getPost().getSone()), "in-sone");
 249         }
 250
 251         /**
 252          * Renders the given link.
 253          *
 254          * @param writer
 255          *            The writer to render the link to
 256          * @param link
 257          *            The link to render
 258          * @param text
 259          *            The text of the link
 260          * @param title
 261          *            The title of the link
 262          * @param cssClass
 263          *            The CSS class of the link
 264          */
 265         private void renderLink(Writer writer, String link, String text, String title, String cssClass) {
 266                 TemplateContext templateContext = templateContextFactory.createTemplateContext();
 267                 templateContext.set("cssClass", cssClass);
 268                 templateContext.set("link", link);
 269                 templateContext.set("text", text);
 270                 templateContext.set("title", title);
 271                 linkTemplate.render(templateContext, writer);
 272         }
 273
 274         //
 275         // STATIC METHODS
 276         //
 277
 278         /**
 279          * Returns up to {@code length} characters from the given text, appending
 280          * “…” if the text is longer.
 281          *
 282          * @param text
 283          *            The text to get an excerpt from
 284          * @param length
 285          *            The maximum length of the excerpt (without the ellipsis)
 286          * @return The excerpt of the text
 287          */
 288         private static String getExcerpt(String text, int length) {
 289                 if (text.length() > length) {
 290                         return text.substring(0, length) + "…";
 291                 }
 292                 return text;
 293         }
 294
 295 }