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                 String soneKey = parameters.get("sone");
  97                 if (soneKey == null) {
  98                         soneKey = "sone";
  99                 }
 100                 Sone sone = (Sone) templateContext.get(soneKey);
 101                 if (sone == null) {
 102                         sone = core.getSone(soneKey, false);
 103                 }
 104                 Request request = (Request) templateContext.get("request");
 105                 SoneTextParserContext context = new SoneTextParserContext(request, sone);
 106                 StringWriter parsedTextWriter = new StringWriter();
 107                 try {
 108                         Iterable<Part> parts = soneTextParser.parse(context, new StringReader(text));
 109                         if (length > -1) {
 110                                 List<Part> shortenedParts = new ArrayList<Part>();
 111                                 for (Part part : parts) {
 112                                         if (part instanceof PlainTextPart) {
 113                                                 String longText = ((PlainTextPart) part).getText();
 114                                                 if (length >= longText.length()) {
 115                                                         shortenedParts.add(part);
 116                                                 } else {
 117                                                         shortenedParts.add(new PlainTextPart(longText.substring(0, length) + "…"));
 118                                                 }
 119                                                 length -= longText.length();
 120                                         } else if (part instanceof LinkPart) {
 121                                                 shortenedParts.add(part);
 122                                                 length -= ((LinkPart) part).getText().length();
 123                                         } else {
 124                                                 shortenedParts.add(part);
 125                                         }
 126                                         if (length <= 0) {
 127                                                 break;
 128                                         }
 129                                 }
 130                                 parts = shortenedParts;
 131                         }
 132                         render(parsedTextWriter, parts);
 133                 } catch (IOException ioe1) {
 134                         /* no exceptions in a StringReader or StringWriter, ignore. */
 135                 }
 136                 return parsedTextWriter.toString();
 137         }
 138
 139         //
 140         // PRIVATE METHODS
 141         //
 142
 143         /**
 144          * Renders the given parts.
 145          *
 146          * @param writer
 147          *            The writer to render the parts to
 148          * @param parts
 149          *            The parts to render
 150          */
 151         private void render(Writer writer, Iterable<Part> parts) {
 152                 for (Part part : parts) {
 153                         render(writer, part);
 154                 }
 155         }
 156
 157         /**
 158          * Renders the given part.
 159          *
 160          * @param writer
 161          *            The writer to render the part to
 162          * @param part
 163          *            The part to render
 164          */
 165         @SuppressWarnings("unchecked")
 166         private void render(Writer writer, Part part) {
 167                 if (part instanceof PlainTextPart) {
 168                         render(writer, (PlainTextPart) part);
 169                 } else if (part instanceof FreenetLinkPart) {
 170                         render(writer, (FreenetLinkPart) part);
 171                 } else if (part instanceof LinkPart) {
 172                         render(writer, (LinkPart) part);
 173                 } else if (part instanceof SonePart) {
 174                         render(writer, (SonePart) part);
 175                 } else if (part instanceof PostPart) {
 176                         render(writer, (PostPart) part);
 177                 } else if (part instanceof Iterable<?>) {
 178                         render(writer, (Iterable<Part>) part);
 179                 }
 180         }
 181
 182         /**
 183          * Renders the given plain-text part.
 184          *
 185          * @param writer
 186          *            The writer to render the part to
 187          * @param plainTextPart
 188          *            The part to render
 189          */
 190         private void render(Writer writer, PlainTextPart plainTextPart) {
 191                 TemplateContext templateContext = templateContextFactory.createTemplateContext();
 192                 templateContext.set("text", plainTextPart.getText());
 193                 plainTextTemplate.render(templateContext, writer);
 194         }
 195
 196         /**
 197          * Renders the given freenet link part.
 198          *
 199          * @param writer
 200          *            The writer to render the part to
 201          * @param freenetLinkPart
 202          *            The part to render
 203          */
 204         private void render(Writer writer, FreenetLinkPart freenetLinkPart) {
 205                 renderLink(writer, "/" + freenetLinkPart.getLink(), freenetLinkPart.getText(), freenetLinkPart.getTitle(), freenetLinkPart.isTrusted() ? "freenet-trusted" : "freenet");
 206         }
 207
 208         /**
 209          * Renders the given link part.
 210          *
 211          * @param writer
 212          *            The writer to render the part to
 213          * @param linkPart
 214          *            The part to render
 215          */
 216         private void render(Writer writer, LinkPart linkPart) {
 217                 renderLink(writer, "/?_CHECKED_HTTP_=" + linkPart.getLink(), linkPart.getText(), linkPart.getTitle(), "internet");
 218         }
 219
 220         /**
 221          * Renders the given Sone part.
 222          *
 223          * @param writer
 224          *            The writer to render the part to
 225          * @param sonePart
 226          *            The part to render
 227          */
 228         private void render(Writer writer, SonePart sonePart) {
 229                 renderLink(writer, "viewSone.html?sone=" + sonePart.getSone().getId(), SoneAccessor.getNiceName(sonePart.getSone()), SoneAccessor.getNiceName(sonePart.getSone()), "in-sone");
 230         }
 231
 232         /**
 233          * Renders the given post part.
 234          *
 235          * @param writer
 236          *            The writer to render the part to
 237          * @param postPart
 238          *            The part to render
 239          */
 240         private void render(Writer writer, PostPart postPart) {
 241                 renderLink(writer, "viewPost.html?post=" + postPart.getPost().getId(), getExcerpt(postPart.getPost().getText(), 20), SoneAccessor.getNiceName(postPart.getPost().getSone()), "in-sone");
 242         }
 243
 244         /**
 245          * Renders the given link.
 246          *
 247          * @param writer
 248          *            The writer to render the link to
 249          * @param link
 250          *            The link to render
 251          * @param text
 252          *            The text of the link
 253          * @param title
 254          *            The title of the link
 255          * @param cssClass
 256          *            The CSS class of the link
 257          */
 258         private void renderLink(Writer writer, String link, String text, String title, String cssClass) {
 259                 TemplateContext templateContext = templateContextFactory.createTemplateContext();
 260                 templateContext.set("cssClass", cssClass);
 261                 templateContext.set("link", link);
 262                 templateContext.set("text", text);
 263                 templateContext.set("title", title);
 264                 linkTemplate.render(templateContext, writer);
 265         }
 266
 267         //
 268         // STATIC METHODS
 269         //
 270
 271         /**
 272          * Returns up to {@code length} characters from the given text, appending
 273          * “…” if the text is longer.
 274          *
 275          * @param text
 276          *            The text to get an excerpt from
 277          * @param length
 278          *            The maximum length of the excerpt (without the ellipsis)
 279          * @return The excerpt of the text
 280          */
 281         private static String getExcerpt(String text, int length) {
 282                 if (text.length() > length) {
 283                         return text.substring(0, length) + "…";
 284                 }
 285                 return text;
 286         }
 287
 288 }