[WIP] Add "Convert to BibTeX format" cleanup

CHANGELOG.md

@@ -22,6 +22,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 - We increased the relative size of the "abstract" field in the entry editor. [Feature request in the forum](http://discourse.jabref.org/t/entry-preview-in-version-4/827)
 - Crossreferenced entries are now used when a BibTex key is generated for an entry with empty fields. [#2811](https://github.com/JabRef/jabref/issues/2811)
 - We now set the `WM_CLASS` of the UI to org-jabref-JabRefMain to allow certain Un*x window managers to properly identify its windows
+- We added an option to convert entries in the biblatex format to BibTeX so that you can again collaborate with these nostalgic diehards. [Feature request in the forum](http://discourse.jabref.org/t/convert-back-from-biblatex-to-bib/)
 - We changed the default paths for the OpenOffice/LibreOffice binaries to the default path for LibreOffice
 - File annotation tab now removes newlines and hyphens before newlines from content and displays an empty String instead of N/A if no contents are found. [#3280](https://github.com/JabRef/jabref/issues/3280)
 - We moved the groups field from the "Other fields" tab to "General" (you may have to reset your editor preferences under Options > Set up general fields)

src/main/java/org/jabref/gui/cleanup/CleanupPresetPanel.java

@@ -6,6 +6,7 @@
 import java.util.Optional;
 import java.util.Set;
 
+import javax.swing.ButtonGroup;
 import javax.swing.JCheckBox;
 import javax.swing.JLabel;
 import javax.swing.JPanel;
@@ -33,6 +34,7 @@ public class CleanupPresetPanel {
     private JCheckBox cleanUpRenamePDFonlyRelativePaths;
     private JCheckBox cleanUpUpgradeExternalLinks;
     private JCheckBox cleanUpBiblatex;
+    private JCheckBox cleanUpBibtex;
     private FieldFormatterCleanupsPanel cleanUpFormatters;
 
     private JPanel panel;
@@ -71,14 +73,19 @@ private void init() {
                 Localization.lang("Upgrade external PDF/PS links to use the '%0' field.", FieldName.FILE));
         cleanUpBiblatex = new JCheckBox(Localization.lang(
                 "Convert to biblatex format (for example, move the value of the 'journal' field to 'journaltitle')"));
+        cleanUpBibtex = new JCheckBox(Localization.lang(
+                "Convert to BibTeX format (for example, move the value of the 'journaltitle' field to 'journal')"));
+        ButtonGroup biblatexConversion = new ButtonGroup(); // Only make "to Biblatex" or "to BibTeX" selectable
+        biblatexConversion.add(cleanUpBiblatex);
+        biblatexConversion.add(cleanUpBibtex);
 
         cleanUpFormatters = new FieldFormatterCleanupsPanel(Localization.lang("Run field formatter:"),
                 Cleanups.DEFAULT_SAVE_ACTIONS);
 
         updateDisplay(cleanupPreset);
 
         FormLayout layout = new FormLayout("left:15dlu, fill:pref:grow",
-                "pref, pref, pref, pref, pref, fill:pref:grow, pref,pref, pref,190dlu, fill:pref:grow,");
+                "pref, pref, pref, pref, pref, fill:pref:grow, pref,pref, pref, pref,190dlu, fill:pref:grow,");
 
         FormBuilder builder = FormBuilder.create().layout(layout);
         builder.add(cleanUpDOI).xyw(1, 1, 2);
@@ -90,9 +97,10 @@ private void init() {
         currentPattern = currentPattern.concat(Globals.prefs.get(JabRefPreferences.IMPORT_FILENAMEPATTERN));
         builder.add(new JLabel(currentPattern)).xy(2, 6);
         builder.add(cleanUpRenamePDFonlyRelativePaths).xy(2, 7);
-        builder.add(cleanUpBiblatex).xyw(1, 8, 2);
-        builder.add(cleanUpISSN).xyw(1, 9, 2);
-        builder.add(cleanUpFormatters).xyw(1, 10, 2);
+        builder.add(cleanUpBibtex).xyw(1, 8, 2);
+        builder.add(cleanUpBiblatex).xyw(1, 9, 2);
+        builder.add(cleanUpISSN).xyw(1, 10, 2);
+        builder.add(cleanUpFormatters).xyw(1, 11, 2);
         panel = builder.build();
         scrollPane = new JScrollPane(panel);
         scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
@@ -111,7 +119,8 @@ private void updateDisplay(CleanupPreset preset) {
         cleanUpRenamePDFonlyRelativePaths.setEnabled(cleanUpRenamePDF.isSelected());
         cleanUpUpgradeExternalLinks.setSelected(preset.isCleanUpUpgradeExternalLinks());
         cleanUpBiblatex.setSelected(preset.isConvertToBiblatex());
-        cleanUpBiblatex.setSelected(preset.isCleanUpISSN());
+        cleanUpBibtex.setSelected(preset.isConvertToBibtex());
+        cleanUpISSN.setSelected(preset.isCleanUpISSN());
         cleanUpFormatters.setValues(preset.getFormatterCleanups());
     }
 
@@ -149,6 +158,9 @@ public CleanupPreset getCleanupPreset() {
         if (cleanUpBiblatex.isSelected()) {
             activeJobs.add(CleanupPreset.CleanupStep.CONVERT_TO_BIBLATEX);
         }
+        if (cleanUpBibtex.isSelected()) {
+            activeJobs.add(CleanupPreset.CleanupStep.CONVERT_TO_BIBTEX);
+        }
 
         activeJobs.add(CleanupPreset.CleanupStep.FIX_FILE_LINKS);
 

src/main/java/org/jabref/logic/cleanup/CleanupPreset.java

@@ -60,6 +60,9 @@ public static CleanupPreset loadFromPreferences(JabRefPreferences preferences) {
         if (preferences.getBoolean(JabRefPreferences.CLEANUP_CONVERT_TO_BIBLATEX)) {
             activeJobs.add(CleanupStep.CONVERT_TO_BIBLATEX);
         }
+        if (preferences.getBoolean(JabRefPreferences.CLEANUP_CONVERT_TO_BIBTEX)) {
+            activeJobs.add(CleanupStep.CONVERT_TO_BIBTEX);
+        }
         if (preferences.getBoolean(JabRefPreferences.CLEANUP_FIX_FILE_LINKS)) {
             activeJobs.add(CleanupStep.FIX_FILE_LINKS);
         }
@@ -102,6 +105,10 @@ public boolean isConvertToBiblatex() {
         return isActive(CleanupStep.CONVERT_TO_BIBLATEX);
     }
 
+    public boolean isConvertToBibtex() {
+        return isActive(CleanupStep.CONVERT_TO_BIBTEX);
+    }
+
     public boolean isRenamePdfOnlyRelativePaths() {
         return isActive(CleanupStep.RENAME_PDF_ONLY_RELATIVE_PATHS);
     }
@@ -117,6 +124,7 @@ public void storeInPreferences(JabRefPreferences preferences) {
         preferences.putBoolean(JabRefPreferences.CLEANUP_UPGRADE_EXTERNAL_LINKS,
                 isActive(CleanupStep.CLEAN_UP_UPGRADE_EXTERNAL_LINKS));
         preferences.putBoolean(JabRefPreferences.CLEANUP_CONVERT_TO_BIBLATEX, isActive(CleanupStep.CONVERT_TO_BIBLATEX));
+        preferences.putBoolean(JabRefPreferences.CLEANUP_CONVERT_TO_BIBTEX, isActive(CleanupStep.CONVERT_TO_BIBTEX));
         preferences.putBoolean(JabRefPreferences.CLEANUP_FIX_FILE_LINKS, isActive(CleanupStep.FIX_FILE_LINKS));
 
         preferences.putStringList(JabRefPreferences.CLEANUP_FORMATTERS, formatterCleanups.getAsStringList(OS.NEWLINE));
@@ -146,6 +154,10 @@ public enum CleanupStep {
          * Converts to biblatex format
          */
         CONVERT_TO_BIBLATEX,
+        /**
+         * Converts to bibtex format
+         */
+        CONVERT_TO_BIBTEX,
         MOVE_PDF,
         FIX_FILE_LINKS,
         CLEAN_UP_ISSN

src/main/java/org/jabref/logic/cleanup/CleanupWorker.java

@@ -51,7 +51,10 @@ private List<CleanupJob> determineCleanupActions(CleanupPreset preset) {
         List<CleanupJob> jobs = new ArrayList<>();
 
         if (preset.isConvertToBiblatex()) {
-            jobs.add(new BiblatexCleanup());
+            jobs.add(new ConvertToBiblatexCleanup());
+        }
+        if (preset.isConvertToBibtex()) {
+            jobs.add(new ConvertToBibtexCleanup());
         }
         if (preset.getFormatterCleanups().isEnabled()) {
             jobs.addAll(preset.getFormatterCleanups().getConfiguredActions());

src/main/java/org/jabref/logic/cleanup/BiblatexCleanup.java → src/main/java/org/jabref/logic/cleanup/ConvertToBiblatexCleanup.java

@@ -14,7 +14,7 @@
 /**
  * Converts the entry to biblatex format.
  */
-public class BiblatexCleanup implements CleanupJob {
+public class ConvertToBiblatexCleanup implements CleanupJob {
 
     @Override
     public List<FieldChange> cleanup(BibEntry entry) {

src/main/java/org/jabref/logic/cleanup/ConvertToBibtexCleanup.java

@@ -0,0 +1,52 @@
+package org.jabref.logic.cleanup;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import org.jabref.model.FieldChange;
+import org.jabref.model.cleanup.CleanupJob;
+import org.jabref.model.entry.BibEntry;
+import org.jabref.model.entry.EntryConverter;
+import org.jabref.model.entry.FieldName;
+import org.jabref.model.strings.StringUtil;
+
+/**
+ * Converts the entry to biblatex format.
+ */
+public class ConvertToBibtexCleanup implements CleanupJob {
+
+    @Override
+    public List<FieldChange> cleanup(BibEntry entry) {
+        List<FieldChange> changes = new ArrayList<>();
+
+        // Dates: get date and fill year and month
+        // If there already exists a non blank/empty value for the field, then it is not overwritten
+        entry.getPublicationDate().ifPresent(date -> {
+            if (StringUtil.isBlank(entry.getField(FieldName.YEAR))) {
+                date.getYear().flatMap(year -> entry.setField(FieldName.YEAR, year.toString())).ifPresent(changes::add);
+            }
+
+            if (StringUtil.isBlank(entry.getField(FieldName.MONTH))) {
+                date.getMonth().flatMap(month -> entry.setField(FieldName.MONTH, month.getJabRefFormat())).ifPresent(changes::add);
+            }
+
+            if (changes.size() > 0) {
+                entry.clearField(FieldName.DATE).ifPresent(changes::add);
+            }
+        });
+
+        for (Map.Entry<String, String> alias : EntryConverter.FIELD_ALIASES_TEX_TO_LTX.entrySet()) {
+            String oldFieldName = alias.getValue();
+            String newFieldName = alias.getKey();
+            entry.getField(oldFieldName).ifPresent(oldValue -> {
+                if (!oldValue.isEmpty() && (!entry.getField(newFieldName).isPresent())) {
+                    // There is content in the old field and no value in the new, so just copy
+                    entry.setField(newFieldName, oldValue).ifPresent(changes::add);
+                    entry.clearField(oldFieldName).ifPresent(changes::add);
+                }
+            });
+        }
+        return changes;
+    }
+}

src/main/java/org/jabref/logic/importer/fileformat/BibtexParser.java

@@ -124,6 +124,10 @@ public List<BibEntry> parseEntries(String bibtexString) throws ParseException {
         return parseEntries(new StringReader(bibtexString));
     }
 
+    public Optional<BibEntry> parseSingleEntry(String bibtexString) throws ParseException {
+        return parseEntries(bibtexString).stream().findFirst();
+    }
+
     /**
      * Will parse the BibTex-Data found when reading from reader. Ignores any encoding supplied in the file by
      * "Encoding: myEncoding".

src/main/java/org/jabref/logic/xmp/XMPUtil.java

@@ -629,7 +629,7 @@ private static void writeToDCSchema(XMPSchemaDublinCore dcSchema, BibEntry entry
                  *
                  * Bibtex-Fields used: year, month
                  */
-                entry.getPublicationDate()
+                entry.getFieldOrAlias(FieldName.DATE)
                         .ifPresent(publicationDate -> dcSchema.addSequenceValue("dc:date", publicationDate));
                 continue;
             }

src/main/java/org/jabref/model/entry/BibEntry.java

@@ -588,8 +588,8 @@ public Optional<String> getTitle() {
      *
      * @return will return the publication date of the entry or null if no year was found.
      */
-    public Optional<String> getPublicationDate() {
-        return getFieldOrAlias(FieldName.DATE);
+    public Optional<Date> getPublicationDate() {
+        return getFieldOrAlias(FieldName.DATE).flatMap(Date::parse);
     }
 
     public String getParsedSerialization() {

src/main/java/org/jabref/model/entry/Date.java

@@ -16,6 +16,18 @@ public class Date {
 
     private final TemporalAccessor date;
 
+    public Date(int year, int month, int dayOfMonth) {
+        this(LocalDate.of(year, month, dayOfMonth));
+    }
+
+    public Date(int year, int month) {
+        this(YearMonth.of(year, month));
+    }
+
+    public Date(int year) {
+        this(Year.of(year));
+    }
+
     public Date(TemporalAccessor date) {
         this.date = date;
     }

src/main/java/org/jabref/preferences/JabRefPreferences.java

@@ -304,6 +304,7 @@ public class JabRefPreferences implements PreferencesService {
     public static final String CLEANUP_RENAME_PDF_ONLY_RELATIVE_PATHS = "CleanUpRenamePDFonlyRelativePaths";
     public static final String CLEANUP_UPGRADE_EXTERNAL_LINKS = "CleanUpUpgradeExternalLinks";
     public static final String CLEANUP_CONVERT_TO_BIBLATEX = "CleanUpConvertToBiblatex";
+    public static final String CLEANUP_CONVERT_TO_BIBTEX = "CleanUpConvertToBibtex";
     public static final String CLEANUP_FIX_FILE_LINKS = "CleanUpFixFileLinks";
     public static final String CLEANUP_FORMATTERS = "CleanUpFormatters";
     public static final String IMPORT_DEFAULT_PDF_IMPORT_STYLE = "importDefaultPDFimportStyle";
@@ -909,12 +910,13 @@ private static Optional<String> getNextUnit(Reader data) throws IOException {
     }
 
     private static void insertDefaultCleanupPreset(Map<String, Object> storage) {
-        EnumSet<CleanupPreset.CleanupStep> deactivedJobs = EnumSet.of(
+        EnumSet<CleanupPreset.CleanupStep> deactivatedJobs = EnumSet.of(
                 CleanupPreset.CleanupStep.CLEAN_UP_UPGRADE_EXTERNAL_LINKS,
                 CleanupPreset.CleanupStep.RENAME_PDF_ONLY_RELATIVE_PATHS,
-                CleanupPreset.CleanupStep.CONVERT_TO_BIBLATEX);
+                CleanupPreset.CleanupStep.CONVERT_TO_BIBLATEX,
+                CleanupPreset.CleanupStep.CONVERT_TO_BIBTEX);
 
-        CleanupPreset preset = new CleanupPreset(EnumSet.complementOf(deactivedJobs), Cleanups.DEFAULT_SAVE_ACTIONS);
+        CleanupPreset preset = new CleanupPreset(EnumSet.complementOf(deactivatedJobs), Cleanups.DEFAULT_SAVE_ACTIONS);
 
         storage.put(CLEANUP_DOI, preset.isCleanUpDOI());
         storage.put(CLEANUP_ISSN, preset.isCleanUpISSN());
@@ -924,6 +926,7 @@ private static void insertDefaultCleanupPreset(Map<String, Object> storage) {
         storage.put(CLEANUP_RENAME_PDF_ONLY_RELATIVE_PATHS, preset.isRenamePdfOnlyRelativePaths());
         storage.put(CLEANUP_UPGRADE_EXTERNAL_LINKS, preset.isCleanUpUpgradeExternalLinks());
         storage.put(CLEANUP_CONVERT_TO_BIBLATEX, preset.isConvertToBiblatex());
+        storage.put(CLEANUP_CONVERT_TO_BIBTEX, preset.isConvertToBibtex());
         storage.put(CLEANUP_FIX_FILE_LINKS, preset.isFixFileLinks());
         storage.put(CLEANUP_FORMATTERS, convertListToString(preset.getFormatterCleanups().getAsStringList(OS.NEWLINE)));
     }

src/main/resources/l10n/JabRef_en.properties

@@ -1892,6 +1892,7 @@ value=value
 Show\ preferences=Show preferences
 Save\ actions=Save actions
 Enable\ save\ actions=Enable save actions
+Convert\ to\ BibTeX\ format\ (for\ example,\ move\ the\ value\ of\ the\ 'journaltitle'\ field\ to\ 'journal')=Convert to BibTeX format (for example, move the value of the 'journaltitle' field to 'journal')
 
 Other\ fields=Other fields
 Show\ remaining\ fields=Show remaining fields

src/test/java/org/jabref/logic/cleanup/BibtexBiblatexRoundtripTest.java

@@ -0,0 +1,62 @@
+package org.jabref.logic.cleanup;
+
+import org.jabref.model.entry.BibEntry;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class BibtexBiblatexRoundtripTest {
+    private BibEntry bibtex;
+    private BibEntry biblatex;
+
+    @BeforeEach
+    void setUp() {
+        bibtex = new BibEntry("article");
+        bibtex.setField("author", "Frame, J. S. and Robinson, G. de B. and Thrall, R. M.");
+        bibtex.setField("title", "The hook graphs of the symmetric groups");
+        bibtex.setField("journal", "Canadian J. Math.");
+        bibtex.setField("fjournal", "Canadian Journal of Mathematics. Journal Canadien de Math\\'ematiques");
+        bibtex.setField("volume", "6");
+        bibtex.setField("year", "1954");
+        bibtex.setField("pages", "316--324");
+        bibtex.setField("issn", "0008-414X");
+        bibtex.setField("mrclass", "20.0X");
+        bibtex.setField("mrnumber", "0062127");
+        bibtex.setField("mrreviewer", "D. E. Littlewood");
+
+        biblatex = new BibEntry("article");
+        biblatex.setField("author", "Frame, J. S. and Robinson, G. de B. and Thrall, R. M.");
+        biblatex.setField("title", "The hook graphs of the symmetric groups");
+        biblatex.setField("journaltitle", "Canadian J. Math.");
+        biblatex.setField("fjournal", "Canadian Journal of Mathematics. Journal Canadien de Math\\'ematiques");
+        biblatex.setField("volume", "6");
+        biblatex.setField("date", "1954");
+        biblatex.setField("pages", "316--324");
+        biblatex.setField("issn", "0008-414X");
+        biblatex.setField("mrclass", "20.0X");
+        biblatex.setField("mrnumber", "0062127");
+        biblatex.setField("mrreviewer", "D. E. Littlewood");
+    }
+
+    @Test
+    void roundTripBibtexToBiblatexIsIdentity() {
+        BibEntry clone = (BibEntry) bibtex.clone();
+        new ConvertToBiblatexCleanup().cleanup(clone);
+        assertEquals(biblatex, clone);
+        new ConvertToBibtexCleanup().cleanup(clone);
+
+        assertEquals(bibtex, clone);
+    }
+
+    @Test
+    void roundTripBiblatexToBibtexIsIdentity() {
+        BibEntry clone = (BibEntry) biblatex.clone();
+        new ConvertToBibtexCleanup().cleanup(clone);
+        assertEquals(bibtex, clone);
+        new ConvertToBiblatexCleanup().cleanup(clone);
+
+        assertEquals(biblatex, clone);
+    }
+}