| 1 | /* |
| 2 | * Copyright (c) 2009 The JOMC Project |
| 3 | * Copyright (c) 2005 Christian Schulte <cs@jomc.org> |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * |
| 10 | * o Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * |
| 13 | * o Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in |
| 15 | * the documentation and/or other materials provided with the |
| 16 | * distribution. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE JOMC PROJECT AND CONTRIBUTORS "AS IS" |
| 19 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| 20 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 21 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE JOMC PROJECT OR |
| 22 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 23 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 24 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| 25 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 26 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| 27 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| 28 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | * |
| 30 | * $Id: SectionEditor.java 891 2009-11-02 03:40:00Z schulte2005 $ |
| 31 | * |
| 32 | */ |
| 33 | package org.jomc.util; |
| 34 | |
| 35 | import java.io.IOException; |
| 36 | import java.text.MessageFormat; |
| 37 | import java.util.ResourceBundle; |
| 38 | import java.util.Stack; |
| 39 | |
| 40 | /** |
| 41 | * Interface to section based editing. |
| 42 | * <p>Section based editing is a two phase process of parsing the editor's input into a corresponding hierarchy of |
| 43 | * {@code Section} instances, followed by rendering the parsed sections to produce the output of the editor. Method |
| 44 | * {@code editLine} returns {@code null} during parsing and the output of the editor on end of input, rendered by |
| 45 | * calling method {@code getOutput}. Parsing is backed by methods {@code getSection} and {@code isSectionFinished}.</p> |
| 46 | * |
| 47 | * @author <a href="mailto:cs@jomc.org">Christian Schulte</a> |
| 48 | * @version $Id: SectionEditor.java 891 2009-11-02 03:40:00Z schulte2005 $ |
| 49 | * |
| 50 | * @see #edit(java.lang.String) |
| 51 | */ |
| 52 | public class SectionEditor extends LineEditor |
| 53 | { |
| 54 | |
| 55 | /** Marker indicating the start of a section. */ |
| 56 | private static final String DEFAULT_SECTION_START = "SECTION-START["; |
| 57 | |
| 58 | /** Marker indicating the end of a section. */ |
| 59 | private static final String DEFAULT_SECTION_END = "SECTION-END"; |
| 60 | |
| 61 | /** Stack of sections. */ |
| 62 | private Stack<Section> stack; |
| 63 | |
| 64 | /** Creates a new {@code SectionEditor} instance. */ |
| 65 | public SectionEditor() |
| 66 | { |
| 67 | super(); |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Creates a new {@code SectionEditor} instance taking a string to use for separating lines. |
| 72 | * |
| 73 | * @param lineSeparator String to use for separating lines. |
| 74 | */ |
| 75 | public SectionEditor( final String lineSeparator ) |
| 76 | { |
| 77 | super( lineSeparator ); |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * Creates a new {@code SectionEditor} instance taking an editor to chain. |
| 82 | * |
| 83 | * @param editor The editor to chain. |
| 84 | */ |
| 85 | public SectionEditor( final LineEditor editor ) |
| 86 | { |
| 87 | super( editor ); |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * Creates a new {@code SectionEditor} instance taking an editor to chain and a string to use for separating lines. |
| 92 | * |
| 93 | * @param editor The editor to chain. |
| 94 | * @param lineSeparator String to use for separating lines. |
| 95 | */ |
| 96 | public SectionEditor( final LineEditor editor, final String lineSeparator ) |
| 97 | { |
| 98 | super( editor, lineSeparator ); |
| 99 | } |
| 100 | |
| 101 | @Override |
| 102 | protected final String editLine( final String line ) throws IOException |
| 103 | { |
| 104 | if ( this.stack == null ) |
| 105 | { |
| 106 | final Section root = new Section(); |
| 107 | root.setMode( Section.MODE_HEAD ); |
| 108 | this.stack = new Stack<Section>(); |
| 109 | this.stack.push( root ); |
| 110 | } |
| 111 | |
| 112 | Section current = this.stack.peek(); |
| 113 | String replacement = null; |
| 114 | |
| 115 | if ( line != null ) |
| 116 | { |
| 117 | final Section child = this.getSection( line ); |
| 118 | |
| 119 | if ( child != null ) |
| 120 | { |
| 121 | child.setStartingLine( line ); |
| 122 | child.setMode( Section.MODE_HEAD ); |
| 123 | |
| 124 | if ( current.getMode() == Section.MODE_TAIL && current.getTailContent().length() > 0 ) |
| 125 | { |
| 126 | final Section s = new Section(); |
| 127 | s.getHeadContent().append( current.getTailContent() ); |
| 128 | current.getTailContent().setLength( 0 ); |
| 129 | current.getSections().add( s ); |
| 130 | current = s; |
| 131 | this.stack.push( current ); |
| 132 | } |
| 133 | |
| 134 | current.getSections().add( child ); |
| 135 | current.setMode( Section.MODE_TAIL ); |
| 136 | this.stack.push( child ); |
| 137 | } |
| 138 | else if ( this.isSectionFinished( line ) ) |
| 139 | { |
| 140 | final Section s = this.stack.pop(); |
| 141 | s.setEndingLine( line ); |
| 142 | |
| 143 | if ( this.stack.isEmpty() ) |
| 144 | { |
| 145 | this.stack = null; |
| 146 | throw new IOException( this.getMessage( "unexpectedEndOfSection", new Object[] |
| 147 | { |
| 148 | s.getName() == null ? "/" : s.getName() |
| 149 | } ) ); |
| 150 | |
| 151 | } |
| 152 | |
| 153 | if ( this.stack.peek().getName() == null && this.stack.size() > 1 ) |
| 154 | { |
| 155 | this.stack.pop(); |
| 156 | } |
| 157 | } |
| 158 | else |
| 159 | { |
| 160 | switch ( current.getMode() ) |
| 161 | { |
| 162 | case Section.MODE_HEAD: |
| 163 | current.getHeadContent().append( line ).append( this.getLineSeparator() ); |
| 164 | break; |
| 165 | |
| 166 | case Section.MODE_TAIL: |
| 167 | current.getTailContent().append( line ).append( this.getLineSeparator() ); |
| 168 | break; |
| 169 | |
| 170 | default: |
| 171 | throw new AssertionError( current.getMode() ); |
| 172 | |
| 173 | } |
| 174 | } |
| 175 | } |
| 176 | else |
| 177 | { |
| 178 | final Section root = this.stack.pop(); |
| 179 | |
| 180 | if ( !this.stack.isEmpty() ) |
| 181 | { |
| 182 | this.stack = null; |
| 183 | throw new IOException( this.getMessage( "unexpectedEndOfSection", new Object[] |
| 184 | { |
| 185 | root.getName() == null ? "/" : root.getName() |
| 186 | } ) ); |
| 187 | |
| 188 | } |
| 189 | |
| 190 | replacement = this.getOutput( root ); |
| 191 | this.stack = null; |
| 192 | } |
| 193 | |
| 194 | return replacement; |
| 195 | } |
| 196 | |
| 197 | /** |
| 198 | * Parses the given line to mark the start of a new section. |
| 199 | * |
| 200 | * @param line The line to parse. |
| 201 | * |
| 202 | * @return The section starting at {@code line} or {@code null} if {@code line} does not mark the start of a |
| 203 | * section. |
| 204 | */ |
| 205 | protected Section getSection( final String line ) |
| 206 | { |
| 207 | Section s = null; |
| 208 | |
| 209 | if ( line != null ) |
| 210 | { |
| 211 | final int startIndex = line.indexOf( DEFAULT_SECTION_START ); |
| 212 | if ( startIndex != -1 ) |
| 213 | { |
| 214 | final String name = line.substring( startIndex + DEFAULT_SECTION_START.length(), |
| 215 | line.indexOf( ']', startIndex + DEFAULT_SECTION_START.length() ) ); |
| 216 | |
| 217 | s = new Section(); |
| 218 | s.setName( name ); |
| 219 | } |
| 220 | } |
| 221 | |
| 222 | return s; |
| 223 | } |
| 224 | |
| 225 | /** |
| 226 | * Parses the given line to mark the end of a section. |
| 227 | * |
| 228 | * @param line The line to parse. |
| 229 | * |
| 230 | * @return {@code true} if {@code line} marks the end of a section; {@code false} if {@code line} does not mark the |
| 231 | * end of a section. |
| 232 | */ |
| 233 | protected boolean isSectionFinished( final String line ) |
| 234 | { |
| 235 | return line != null && line.indexOf( DEFAULT_SECTION_END ) != -1; |
| 236 | } |
| 237 | |
| 238 | /** |
| 239 | * Edits a section. |
| 240 | * <p>This method does not change any content by default. Overriding classes may use this method for editing |
| 241 | * sections prior to rendering.</p> |
| 242 | * |
| 243 | * @param section The section to edit. |
| 244 | * |
| 245 | * @throws NullPointerException if {@code section} is {@code null}. |
| 246 | * @throws IOException if editing fails. |
| 247 | */ |
| 248 | protected void editSection( final Section section ) throws IOException |
| 249 | { |
| 250 | if ( section == null ) |
| 251 | { |
| 252 | throw new NullPointerException( "section" ); |
| 253 | } |
| 254 | } |
| 255 | |
| 256 | /** |
| 257 | * Edits a section recursively. |
| 258 | * |
| 259 | * @param section The section to edit recursively. |
| 260 | * |
| 261 | * @throws NullPointerException if {@code section} is {@code null}. |
| 262 | * @throws IOException if editing fails. |
| 263 | */ |
| 264 | private void editSections( final Section section ) throws IOException |
| 265 | { |
| 266 | if ( section == null ) |
| 267 | { |
| 268 | throw new NullPointerException( "section" ); |
| 269 | } |
| 270 | |
| 271 | this.editSection( section ); |
| 272 | for ( Section child : section.getSections() ) |
| 273 | { |
| 274 | this.editSections( child ); |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | /** |
| 279 | * Gets the output of the editor. |
| 280 | * <p>This method calls method {@code editSection()} for each section of the editor prior to rendering the sections |
| 281 | * to produce the output of the editor.</p> |
| 282 | * |
| 283 | * @param section The section to start rendering the editor's output with. |
| 284 | * |
| 285 | * @return The output of the editor. |
| 286 | * |
| 287 | * @throws NullPointerException if {@code section} is {@code null}. |
| 288 | * @throws IOException if editing or rendering fails. |
| 289 | */ |
| 290 | protected String getOutput( final Section section ) throws IOException |
| 291 | { |
| 292 | if ( section == null ) |
| 293 | { |
| 294 | throw new NullPointerException( "section" ); |
| 295 | } |
| 296 | |
| 297 | this.editSections( section ); |
| 298 | return this.renderSections( section, new StringBuilder() ).toString(); |
| 299 | } |
| 300 | |
| 301 | /** |
| 302 | * Appends the content of a given section to a given buffer. |
| 303 | * |
| 304 | * @param section The section to render. |
| 305 | * @param buffer The buffer to append the content of {@code section} to. |
| 306 | * |
| 307 | * @return {@code buffer} with content of {@code section} appended. |
| 308 | */ |
| 309 | private StringBuilder renderSections( final Section section, final StringBuilder buffer ) |
| 310 | { |
| 311 | if ( section.getStartingLine() != null ) |
| 312 | { |
| 313 | buffer.append( section.getStartingLine() ).append( this.getLineSeparator() ); |
| 314 | } |
| 315 | |
| 316 | buffer.append( section.getHeadContent() ); |
| 317 | |
| 318 | for ( Section child : section.getSections() ) |
| 319 | { |
| 320 | this.renderSections( child, buffer ); |
| 321 | } |
| 322 | |
| 323 | buffer.append( section.getTailContent() ); |
| 324 | |
| 325 | if ( section.getEndingLine() != null ) |
| 326 | { |
| 327 | buffer.append( section.getEndingLine() ).append( this.getLineSeparator() ); |
| 328 | } |
| 329 | |
| 330 | return buffer; |
| 331 | } |
| 332 | |
| 333 | private String getMessage( final String key, final Object arguments ) |
| 334 | { |
| 335 | return new MessageFormat( ResourceBundle.getBundle( SectionEditor.class.getName(). |
| 336 | replace( '.', '/' ) ).getString( key ) ).format( arguments ); |
| 337 | |
| 338 | } |
| 339 | |
| 340 | } |