File indexing completed on 2024-05-12 16:46:35

 /***************************************************************************
     Copyright (C) 2008-2009 Robby Stephenson <robby@periapsis.org>
  ***************************************************************************/
 
 /***************************************************************************
  *                                                                         *
  *   This program is free software; you can redistribute it and/or         *
  *   modify it under the terms of the GNU General Public License as        *
  *   published by the Free Software Foundation; either version 2 of        *
  *   the License or (at your option) version 3 or any later version        *
  *   accepted by the membership of KDE e.V. (or its successor approved     *
  *   by the membership of KDE e.V.), which shall act as a proxy            *
  *   defined in Section 14 of version 3 of the license.                    *
  *                                                                         *
  *   This program is distributed in the hope that it will be useful,       *
  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  *   GNU General Public License for more details.                          *
  *                                                                         *
  *   You should have received a copy of the GNU General Public License     *
  *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  *                                                                         *
  ***************************************************************************/
 
 #include "xmlstatehandler.h"
 #include "tellico_xml.h"
 #include "../collection.h"
 #include "../collectionfactory.h"
 #include "../collections/bibtexcollection.h"
 #include "../fieldformat.h"
 #include "../images/image.h"
 #include "../images/imageinfo.h"
 #include "../images/imagefactory.h"
 #include "../utils/isbnvalidator.h"
 #include "../utils/string_utils.h"
 #include "../tellico_debug.h"
 
 #include <KLocalizedString>
 
 #include <QRegularExpression>
 
 namespace {
 
 inline
 QString attValue(const QXmlStreamAttributes& atts, const char* name, const QString& defaultValue=QString()) {
   return atts.hasAttribute(QLatin1String(name)) ? atts.value(QLatin1String(name)).toString() : defaultValue;
 }
 
 inline
 QString attValue(const QXmlStreamAttributes& atts, const char* name, const char* defaultValue) {
   Q_ASSERT(defaultValue);
   return attValue(atts, name, QLatin1String(defaultValue));
 }
 
 inline
 QString realFieldName(int syntaxVersion, const QStringRef& localName) {
   return (syntaxVersion < 2 && localName == QLatin1String("keywords")) ?
     QStringLiteral("keyword") :
     localName.toString();
 }
 
 }
 
 using Tellico::Import::SAX::StateHandler;
 using Tellico::Import::SAX::NullHandler;
 using Tellico::Import::SAX::RootHandler;
 using Tellico::Import::SAX::DocumentHandler;
 using Tellico::Import::SAX::CollectionHandler;
 using Tellico::Import::SAX::FieldsHandler;
 using Tellico::Import::SAX::FieldHandler;
 using Tellico::Import::SAX::FieldPropertyHandler;
 using Tellico::Import::SAX::BibtexPreambleHandler;
 using Tellico::Import::SAX::BibtexMacrosHandler;
 using Tellico::Import::SAX::BibtexMacroHandler;
 using Tellico::Import::SAX::EntryHandler;
 using Tellico::Import::SAX::FieldValueContainerHandler;
 using Tellico::Import::SAX::FieldValueHandler;
 using Tellico::Import::SAX::DateValueHandler;
 using Tellico::Import::SAX::TableColumnHandler;
 using Tellico::Import::SAX::ImagesHandler;
 using Tellico::Import::SAX::ImageHandler;
 using Tellico::Import::SAX::FiltersHandler;
 using Tellico::Import::SAX::FilterHandler;
 using Tellico::Import::SAX::FilterRuleHandler;
 using Tellico::Import::SAX::BorrowersHandler;
 using Tellico::Import::SAX::BorrowerHandler;
 using Tellico::Import::SAX::LoanHandler;
 
 StateHandler* StateHandler::nextHandler(const QStringRef& ns_, const QStringRef& localName_) {
   StateHandler* handler = nextHandlerImpl(ns_, localName_);
   if(!handler) {
     myWarning() << "no handler for" << localName_;
   }
   return handler ? handler : new NullHandler(d);
 }
 
 StateHandler* RootHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(localName_ == QLatin1String("tellico") || localName_ == QLatin1String("bookcase")) {
     return new DocumentHandler(d);
   }
   return new RootHandler(d);
 }
 
 StateHandler* DocumentHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(localName_ == QLatin1String("collection")) {
     return new CollectionHandler(d);
   } else if(localName_ == QLatin1String("filters")) {
     return new FiltersHandler(d);
   } else if(localName_ == QLatin1String("borrowers")) {
     return new BorrowersHandler(d);
   }
   return nullptr;
 }
 
 bool DocumentHandler::start(const QStringRef&, const QStringRef& localName_, const QXmlStreamAttributes& atts_) {
   // the syntax version field name changed from "version" to "syntaxVersion" in version 3
   QStringRef syntaxVersion = atts_.value(QLatin1String("syntaxVersion"));
   if(syntaxVersion.isEmpty()) {
     syntaxVersion = atts_.value(QLatin1String("version"));
     if(syntaxVersion.isEmpty()) {
       myWarning() << "no syntax version";
       return false;
     }
   }
   d->syntaxVersion = syntaxVersion.toUInt();
   if(d->syntaxVersion > Tellico::XML::syntaxVersion) {
     d->error = i18n("It is from a future version of Tellico.");
     return false;
   }
   if((d->syntaxVersion > 6 && localName_ != QLatin1String("tellico")) ||
      (d->syntaxVersion < 7 && localName_ != QLatin1String("bookcase"))) {
     // no error message
     myWarning() << "bad root element name";
     return false;
   }
   d->ns = d->syntaxVersion > 6 ? Tellico::XML::nsTellico : Tellico::XML::nsBookcase;
   return true;
 }
 
 bool DocumentHandler::end(const QStringRef&, const QStringRef&) {
   return true;
 }
 
 StateHandler* CollectionHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if((d->syntaxVersion > 3 && localName_ == QLatin1String("fields")) ||
      (d->syntaxVersion < 4 && localName_ == QLatin1String("attributes"))) {
     return new FieldsHandler(d);
   } else if(localName_ == QLatin1String("bibtex-preamble")) {
     return new BibtexPreambleHandler(d);
   } else if(localName_ == QLatin1String("macros")) {
     return new BibtexMacrosHandler(d);
   } else if(localName_ == d->entryName) {
     return new EntryHandler(d);
   } else if(localName_ == QLatin1String("images")) {
     return new ImagesHandler(d);
   }
   return nullptr;
 }
 
 bool CollectionHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes& atts_) {
   d->collTitle = attValue(atts_, "title");
   d->collType = atts_.value(QLatin1String("type")).toInt();
   if(d->syntaxVersion > 6) {
     d->entryName = QStringLiteral("entry");
   } else {
     // old attribute
     d->entryName = attValue(atts_, "unit");
     // for error recovery, assume entry name is default if empty for now
     if(d->entryName.isEmpty()) {
       d->entryName = QLatin1String("entry");
     }
   }
   return true;
 }
 
 bool CollectionHandler::end(const QStringRef&, const QStringRef&) {
   if(!d->coll) {
     myWarning() << "no collection created";
     return false;
   }
   d->coll->addEntries(d->entries);
 
   // a little hidden capability was to just have a local path as an image file name
   // and on reading the xml file, Tellico would load the image file, too
   // here, we need to scan all the image values in all the entries and check
   // maybe this is too costly, especially since the capability wasn't advertised?
 
   const int maxImageWarnings = 3;
   int imageWarnings = 0;
 
   Data::FieldList fields = d->coll->imageFields();
   foreach(Data::EntryPtr entry, d->entries) {
     foreach(Data::FieldPtr field, fields) {
       QString value = entry->field(field);
       if(value.isEmpty()) {
         continue;
       }
       // image info should have already been loaded
       // if not, then there was no <image> in the XML
       // so it's a url, but maybe link only
       if(!ImageFactory::hasImageInfo(value)) {
         const QUrl u = QUrl::fromUserInput(value);
         // the image file name is a valid URL, but I want it to be a local URL or non empty remote one
         if(u.isValid() && (u.isLocalFile() || !u.host().isEmpty())) {
           const QString result = ImageFactory::addImage(u, !d->showImageLoadErrors || imageWarnings >= maxImageWarnings /* quiet */);
           if(result.isEmpty()) {
             // clear value for the field in this case
             value.clear();
             ++imageWarnings;
           } else {
             value = result;
           }
         } else {
           value = Data::Image::idClean(value);
         }
         // reset the image id to be whatever was loaded
         entry->setField(field->name(), value, false /* no modified date update */);
       }
     }
   }
   return true;
 }
 
 StateHandler* FieldsHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if((d->syntaxVersion > 3 && localName_ == QLatin1String("field")) ||
      (d->syntaxVersion < 4 && localName_ == QLatin1String("attribute"))) {
     return new FieldHandler(d);
   }
   return nullptr;
 }
 
 bool FieldsHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes&) {
   d->defaultFields = false;
   return true;
 }
 
 bool FieldsHandler::end(const QStringRef&, const QStringRef&) {
   // add default fields if there was a default field name, or no names at all
   const bool addFields = d->defaultFields || d->fields.isEmpty();
   // in syntax 4, the element name was changed to "entry", always, rather than depending on
   // on the entryName of the collection.
   if(d->syntaxVersion > 3) {
     d->entryName = QStringLiteral("entry");
     Data::Collection::Type type = static_cast<Data::Collection::Type>(d->collType);
     d->coll = CollectionFactory::collection(type, addFields);
   } else {
     d->coll = CollectionFactory::collection(d->entryName, addFields);
   }
 
   if(!d->collTitle.isEmpty()) {
     d->coll->setTitle(d->collTitle);
   }
 
   // add a default field for ID
   // checking the defaultFields bool since if it is true, we already added these default fields
   // even for old syntax versions
   if(d->syntaxVersion < 11 && !d->defaultFields) {
     d->coll->addField(Data::Field::createDefaultField(Data::Field::IDField));
   }
   // now add all the new fields
   d->coll->addFields(d->fields);
   if(d->syntaxVersion < 11 && !d->defaultFields) {
     d->coll->addField(Data::Field::createDefaultField(Data::Field::CreatedDateField));
     d->coll->addField(Data::Field::createDefaultField(Data::Field::ModifiedDateField));
   }
 
 //  as a special case, for old book collections with a bibtex-id field, convert to Bibtex
   if(d->syntaxVersion < 4 && d->collType == Data::Collection::Book
      && d->coll->hasField(QStringLiteral("bibtex-id"))) {
     d->coll = Data::BibtexCollection::convertBookCollection(d->coll);
   }
 
   return true;
 }
 
 StateHandler* FieldHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(localName_ == QLatin1String("prop")) {
     return new FieldPropertyHandler(d);
   }
   return nullptr;
 }
 
 bool FieldHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes& atts_) {
   // special case: if the i18n attribute equals true, then translate the title, description, category, and allowed
   const bool isI18n = atts_.value(QLatin1String("i18n")) == QLatin1String("true");
 
   const QString name = attValue(atts_, "name", "unknown");
   if(name == QLatin1String("_default")) {
     d->defaultFields = true;
     return true;
   }
 
   QString title  = attValue(atts_, "title", i18n("Unknown"));
   if(isI18n && !title.isEmpty()) {
     title = i18n(title.toUtf8().constData());
   }
 
   QString typeStr = attValue(atts_, "type", QString::number(Data::Field::Line));
   Data::Field::Type type = static_cast<Data::Field::Type>(typeStr.toInt());
 
   Data::FieldPtr field;
   if(type == Data::Field::Choice) {
     QStringList allowed = FieldFormat::splitValue(attValue(atts_, "allowed"), FieldFormat::RegExpSplit);
     if(isI18n) {
       for(QStringList::Iterator word = allowed.begin(); word != allowed.end(); ++word) {
         (*word) = i18n((*word).toUtf8().constData());
       }
     }
     field = new Data::Field(name, title, allowed);
   } else {
     field = new Data::Field(name, title, type);
   }
 
   QString cat = attValue(atts_, "category");
   // at one point, the categories had keyboard accels
   if(d->syntaxVersion < 9) {
     cat.remove(QLatin1Char('&'));
   }
   if(isI18n && !cat.isEmpty()) {
     cat = i18n(cat.toUtf8().constData());
   }
   field->setCategory(cat);
 
   int flags = atts_.value(QLatin1String("flags")).toInt();
   // I also changed the enum values for syntax 3, but the only custom field
   // would have been bibtex-id
   if(d->syntaxVersion < 3 && name == QLatin1String("bibtex-id")) {
     flags = 0;
   }
 
   // in syntax version 4, added a flag to disallow deleting attributes
   // if it's a version before that and is the title, then add the flag
   if(d->syntaxVersion < 4 && name == QLatin1String("title")) {
     flags |= Data::Field::NoDelete;
   }
   // some of the flags may have been set in the constructor
   // in the case of old Dependent fields changing, for example
   // so combine with the existing flags
   field->setFlags(field->flags() | flags);
 
   QString formatStr = attValue(atts_, "format", QString::number(FieldFormat::FormatNone));
   FieldFormat::Type formatType = static_cast<FieldFormat::Type>(formatStr.toInt());
   field->setFormatType(formatType);
 
   QString desc = attValue(atts_, "description");
   if(isI18n && !desc.isEmpty()) {
     desc = i18n(desc.toUtf8().constData());
   }
   field->setDescription(desc);
 
   if(d->syntaxVersion < 5 && atts_.hasAttribute(QLatin1String("bibtex-field"))) {
     field->setProperty(QStringLiteral("bibtex"), attValue(atts_, "bibtex-field"));
   }
 
   // for syntax 8, rating fields got their own type
   if(d->syntaxVersion < 8) {
     Data::Field::convertOldRating(field); // does all its own checking
   }
   d->fields.append(field);
 
   return true;
 }
 
 bool FieldHandler::end(const QStringRef&, const QStringRef&) {
   // the value template for derived values used to be the field description
   // now it is the 'template' property
   // for derived value fields, if there is no property and the description has a '%'
   // move it to the property
   //
   // might be empty is we're only adding default fields
   if(!d->fields.isEmpty()) {
     Data::FieldPtr field = d->fields.back();
     if(field->hasFlag(Data::Field::Derived) &&
        field->property(QStringLiteral("template")).isEmpty() &&
        field->description().contains(QLatin1Char('%'))) {
       field->setProperty(QStringLiteral("template"), field->description());
       field->setDescription(QString());
     }
   }
 
   return true;
 }
 
 bool FieldPropertyHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes& atts_) {
   // there should be at least one field already so we can add properties to it
   Q_ASSERT(!d->fields.isEmpty());
   Data::FieldPtr field = d->fields.back();
 
   m_propertyName = attValue(atts_, "name");
 
   // all track fields in music collections prior to version 9 get converted to three columns
   if(d->syntaxVersion < 9) {
     if(d->collType == Data::Collection::Album && field->name() == QLatin1String("track")) {
       field->setProperty(QStringLiteral("columns"), QStringLiteral("3"));
       field->setProperty(QStringLiteral("column1"), i18n("Title"));
       field->setProperty(QStringLiteral("column2"), i18n("Artist"));
       field->setProperty(QStringLiteral("column3"), i18n("Length"));
     } else if(d->collType == Data::Collection::Video && field->name() == QLatin1String("cast")) {
       field->setProperty(QStringLiteral("column1"), i18n("Actor/Actress"));
       field->setProperty(QStringLiteral("column2"), i18n("Role"));
     }
   }
 
   return true;
 }
 
 bool FieldPropertyHandler::end(const QStringRef&, const QStringRef&) {
   Q_ASSERT(!m_propertyName.isEmpty());
   // add the previous property
   Data::FieldPtr field = d->fields.back();
   field->setProperty(m_propertyName, d->text);
   return true;
 }
 
 bool BibtexPreambleHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes&) {
   return true;
 }
 
 bool BibtexPreambleHandler::end(const QStringRef&, const QStringRef&) {
   Q_ASSERT(d->coll);
   if(d->coll && d->collType == Data::Collection::Bibtex && !d->text.isEmpty()) {
     Data::BibtexCollection* c = static_cast<Data::BibtexCollection*>(d->coll.data());
     c->setPreamble(d->text);
   }
   return true;
 }
 
 StateHandler* BibtexMacrosHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(localName_ == QLatin1String("macro")) {
     return new BibtexMacroHandler(d);
   }
   return nullptr;
 }
 
 bool BibtexMacrosHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes&) {
   return true;
 }
 
 bool BibtexMacrosHandler::end(const QStringRef&, const QStringRef&) {
   return true;
 }
 
 bool BibtexMacroHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes& atts_) {
   m_macroName = attValue(atts_, "name");
   return true;
 }
 
 bool BibtexMacroHandler::end(const QStringRef&, const QStringRef&) {
   if(d->coll && d->collType == Data::Collection::Bibtex && !m_macroName.isEmpty() && !d->text.isEmpty()) {
     Data::BibtexCollection* c = static_cast<Data::BibtexCollection*>(d->coll.data());
     c->addMacro(m_macroName, d->text);
   }
   return true;
 }
 
 StateHandler* EntryHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(d->coll->hasField(realFieldName(d->syntaxVersion, localName_))) {
     return new FieldValueHandler(d);
   }
   return new FieldValueContainerHandler(d);
 }
 
 bool EntryHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes& atts_) {
   // the entries must come after the fields
   if(!d->coll || d->coll->fields().isEmpty()) {
     // special case for very old versions which did not have user-editable fields
     // also maybe a new version has bad formatting, try to recover by assuming default fields
     d->defaultFields = true;
     FieldsHandler handler(d);
     // fake the end of a fields element, which will add the default fields
     handler.end(QStringRef(), QStringRef());
     myWarning() << "entries should come after fields are defined, attempting to recover";
   }
   bool ok;
   const int id = atts_.value(QLatin1String("id")).toInt(&ok);
   Data::EntryPtr entry;
   if(ok && id > -1) {
     entry = new Data::Entry(d->coll, id);
   } else {
     entry = new Data::Entry(d->coll);
   }
   d->entries.append(entry);
   return true;
 }
 
 bool EntryHandler::end(const QStringRef&, const QStringRef&) {
   Data::EntryPtr entry = d->entries.back();
   Q_ASSERT(entry);
   if(!d->modifiedDate.isEmpty() && d->coll->hasField(QStringLiteral("mdate"))) {
     entry->setField(QStringLiteral("mdate"), d->modifiedDate);
     d->modifiedDate.clear();
   }
   return true;
 }
 
 StateHandler* FieldValueContainerHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(d->coll->hasField(realFieldName(d->syntaxVersion, localName_))) {
     return new FieldValueHandler(d);
   }
   return new FieldValueContainerHandler(d);
 }
 
 bool FieldValueContainerHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes&) {
   return true;
 }
 
 bool FieldValueContainerHandler::end(const QStringRef&, const QStringRef&) {
   Data::FieldPtr f = d->currentField;
   if(f && f->type() == Data::Field::Table) {
     Data::EntryPtr entry = d->entries.back();
     Q_ASSERT(entry);
     QString fieldValue = entry->field(f->name());
     // don't allow table value to end with empty row
     while(fieldValue.endsWith(FieldFormat::rowDelimiterString())) {
       fieldValue.chop(FieldFormat::rowDelimiterString().length());
       // no need to update the modified date when setting the entry's field value
       entry->setField(f->name(), fieldValue, false /* no modified date update */);
     }
   }
 
   return true;
 }
 
 StateHandler* FieldValueHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(localName_ == QLatin1String("year") ||
      localName_ == QLatin1String("month") ||
      localName_ == QLatin1String("day")) {
     return new DateValueHandler(d);
   } else if(localName_ == QLatin1String("column")) {
     return new TableColumnHandler(d);
   }
   return nullptr;
 }
 
 bool FieldValueHandler::start(const QStringRef&, const QStringRef& localName_, const QXmlStreamAttributes& atts_) {
   d->currentField = d->coll->fieldByName(realFieldName(d->syntaxVersion, localName_));
   Q_ASSERT(d->currentField);
   m_i18n = atts_.value(QLatin1String("i18n")) == QLatin1String("true");
   m_validateISBN = (localName_ == QLatin1String("isbn")) &&
                    (atts_.value(QLatin1String("validate")) != QLatin1String("no"));
   return true;
 }
 
 bool FieldValueHandler::end(const QStringRef&, const QStringRef& localName_) {
   Data::EntryPtr entry = d->entries.back();
   Q_ASSERT(entry);
   QString fieldName = d->currentField ? d->currentField->name() : realFieldName(d->syntaxVersion, localName_);
 
   Data::FieldPtr f = d->currentField;
   if(!f) {
     myWarning() << "no field named " << fieldName;
     return true;
   }
   // if it's a derived value, no field value is added
   if(f->hasFlag(Data::Field::Derived)) {
     return true;
   }
 
   QString fieldValue = d->text;
   if(d->syntaxVersion < 4 && f->type() == Data::Field::Bool) {
     // in version 3 and prior, checkbox attributes had no text(), set it to "true"
     fieldValue = QStringLiteral("true");
   } else if(d->syntaxVersion < 8 && f->type() == Data::Field::Rating) {
     // in version 8, old rating fields get changed
     bool ok;
     uint i = Tellico::toUInt(fieldValue, &ok);
     if(ok) {
       fieldValue = QString::number(i);
     }
   } else if(!d->textBuffer.isEmpty()) {
     // for dates and tables, the value is built up from child elements
     if(!d->text.isEmpty()) {
       myWarning() << "ignoring value for field" << localName_ << ":" << d->text;
     }
     fieldValue = d->textBuffer;
     // the text buffer has the column delimiter at the end, remove it
     if(f->type() == Data::Field::Table) {
       fieldValue.chop(FieldFormat::columnDelimiterString().length());
     }
     d->textBuffer.clear();
   } else if(fieldValue.isEmpty() && f->type() == Data::Field::Table) {
     // allow for empty table rows
     fieldValue = FieldFormat::rowDelimiterString();
   }
   // this is not an else branch, the data may be in the textBuffer
   if(d->syntaxVersion < 9 && d->coll->type() == Data::Collection::Album && fieldName == QLatin1String("track")) {
     // yes, this assumes the artist has already been set
     fieldValue += FieldFormat::columnDelimiterString();
     fieldValue += entry->field(QStringLiteral("artist"));
   }
   if(fieldValue.isEmpty()) {
     return true;
   }
 
   // special case: if the i18n attribute equals true, then translate the title, description, and category
   if(m_i18n) {
     fieldValue = i18n(fieldValue.toUtf8().constData());
   }
   // special case for isbn fields, go ahead and validate
   if(m_validateISBN) {
     ISBNValidator val(nullptr);
     val.fixup(fieldValue);
   }
   if(f->type() == Data::Field::Table) {
     QString oldValue = entry->field(fieldName);
     if(!oldValue.isEmpty()) {
       if(!oldValue.endsWith(FieldFormat::rowDelimiterString())) {
         oldValue += FieldFormat::rowDelimiterString();
       }
       fieldValue.prepend(oldValue);
     }
   } else if(f->hasFlag(Data::Field::AllowMultiple)) {
     // for fields with multiple values, we need to add on the new value
     const QString oldValue = entry->field(fieldName);
     if(!oldValue.isEmpty()) {
       fieldValue = oldValue + FieldFormat::delimiterString() + fieldValue;
     }
   }
 
   // since the modified date value in the entry gets changed every time we set a new value
   // we have to save it and set it after changing all the others
   if(fieldName == QLatin1String("mdate")) {
     d->modifiedDate = fieldValue;
   } else {
     // no need to update the modified date when setting the entry's field value
     entry->setField(fieldName, fieldValue, false /* no modified date update */);
   }
   return true;
 }
 
 bool DateValueHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes&) {
   return true;
 }
 
 bool DateValueHandler::end(const QStringRef&, const QStringRef& localName_) {
   QStringList tokens;
   if(d->textBuffer.isEmpty()) {
     // the data value is y-m-d even if there are no date values, so create list of blank tokens
     tokens = QStringList() << QString() << QString() << QString();
   } else {
 #if (QT_VERSION < QT_VERSION_CHECK(5, 14, 0))
     tokens = d->textBuffer.split(QLatin1Char('-'), QString::KeepEmptyParts);
 #else
     tokens = d->textBuffer.split(QLatin1Char('-'), Qt::KeepEmptyParts);
 #endif
   }
   Q_ASSERT(tokens.size() == 3);
   while(tokens.size() < 3) {
     tokens += QString();
   }
   if(localName_ == QLatin1String("year")) {
     tokens[0] = d->text;
   } else if(localName_ == QLatin1String("month")) {
     // enforce two digits for month
     while(d->text.length() < 2) {
       d->text.prepend(QLatin1Char('0'));
     }
     tokens[1] = d->text;
   } else if(localName_ == QLatin1String("day")) {
     // enforce two digits for day
     while(d->text.length() < 2) {
       d->text.prepend(QLatin1Char('0'));
     }
     tokens[2] = d->text;
   }
   d->textBuffer = tokens.join(QLatin1String("-"));
   return true;
 }
 
 bool TableColumnHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes&) {
   return true;
 }
 
 bool TableColumnHandler::end(const QStringRef&, const QStringRef&) {
   // for old collections, if the second column holds the track length, bump it to next column
   if(d->syntaxVersion < 9 &&
      d->coll->type() == Data::Collection::Album &&
      d->currentField->name() == QLatin1String("track") &&
      !d->textBuffer.isEmpty() &&
      d->textBuffer.contains(FieldFormat::columnDelimiterString()) == 0) {
     const QRegularExpression rx(QLatin1String("^\\d+:\\d\\d$"));
     if(rx.match(d->text).hasMatch()) {
       d->text += FieldFormat::columnDelimiterString();
       d->text += d->entries.back()->field(QStringLiteral("artist"));
     }
   }
 
   d->textBuffer += d->text + FieldFormat::columnDelimiterString();
   return true;
 }
 
 StateHandler* ImagesHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(localName_ == QLatin1String("image")) {
     return new ImageHandler(d);
   }
   return nullptr;
 }
 
 bool ImagesHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes&) {
   // reset variable that gets updated in the image handler
   d->hasImages = false;
   return true;
 }
 
 bool ImagesHandler::end(const QStringRef&, const QStringRef&) {
   return true;
 }
 
 bool ImageHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes& atts_) {
   m_format = attValue(atts_, "format");
   m_link = atts_.value(QLatin1String("link")) == QLatin1String("true");
   // idClean() already calls shareString()
   m_imageId = m_link ? shareString(attValue(atts_, "id"))
                      : Data::Image::idClean(attValue(atts_, "id"));
   m_width = atts_.value(QLatin1String("width")).toInt();
   m_height = atts_.value(QLatin1String("height")).toInt();
   return true;
 }
 
 bool ImageHandler::end(const QStringRef&, const QStringRef&) {
   bool needToAddInfo = true;
   if(d->loadImages && !d->text.isEmpty()) {
     QByteArray ba = QByteArray::fromBase64(d->text.toLatin1());
     if(!ba.isEmpty()) {
       QString result = ImageFactory::addImage(ba, m_format, m_imageId);
       if(result.isEmpty()) {
         myDebug() << "null image for" << m_imageId;
       }
       d->hasImages = true;
       needToAddInfo = false;
     }
   }
   if(needToAddInfo) {
     // a width or height of 0 is ok here
     Data::ImageInfo info(m_imageId, m_format.toLatin1(), m_width, m_height, m_link);
     ImageFactory::cacheImageInfo(info);
   }
   return true;
 }
 
 StateHandler* FiltersHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(localName_ == QLatin1String("filter")) {
     return new FilterHandler(d);
   }
   return nullptr;
 }
 
 bool FiltersHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes&) {
   return true;
 }
 
 bool FiltersHandler::end(const QStringRef&, const QStringRef&) {
   return true;
 }
 
 StateHandler* FilterHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(localName_ == QLatin1String("rule")) {
     return new FilterRuleHandler(d);
   }
   return nullptr;
 }
 
 bool FilterHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes& atts_) {
   d->filter = new Filter(Filter::MatchAny);
   d->filter->setName(attValue(atts_, "name"));
 
   if(atts_.value(QLatin1String("match")) == QLatin1String("all")) {
     d->filter->setMatch(Filter::MatchAll);
   }
   return true;
 }
 
 bool FilterHandler::end(const QStringRef&, const QStringRef&) {
   if(d->coll && !d->filter->isEmpty()) {
     d->coll->addFilter(d->filter);
   }
   d->filter = FilterPtr();
   return true;
 }
 
 bool FilterRuleHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes& atts_) {
   QString field = attValue(atts_, "field");
   // empty field means match any of them
   QString pattern = attValue(atts_, "pattern");
   // empty pattern is bad
   if(pattern.isEmpty()) {
     myWarning() << "empty rule!";
     return true;
   }
   /* If anything is updated here, be sure to update tellicoxmlexporter */
   QString function = attValue(atts_, "function").toLower();
   FilterRule::Function func;
   if(function == QLatin1String("contains")) {
     func = FilterRule::FuncContains;
   } else if(function == QLatin1String("notcontains")) {
     func = FilterRule::FuncNotContains;
   } else if(function == QLatin1String("equals")) {
     func = FilterRule::FuncEquals;
   } else if(function == QLatin1String("notequals")) {
     func = FilterRule::FuncNotEquals;
   } else if(function == QLatin1String("regexp")) {
     func = FilterRule::FuncRegExp;
   } else if(function == QLatin1String("notregexp")) {
     func = FilterRule::FuncNotRegExp;
   } else if(function == QLatin1String("before")) {
     func = FilterRule::FuncBefore;
   } else if(function == QLatin1String("after")) {
     func = FilterRule::FuncAfter;
   } else if(function == QLatin1String("greaterthan")) {
     func = FilterRule::FuncGreater;
   } else if(function == QLatin1String("lessthan")) {
     func = FilterRule::FuncLess;
   } else {
     myWarning() << "invalid rule function:" << function;
     return true;
   }
   d->filter->append(new FilterRule(field, pattern, func));
   return true;
 }
 
 bool FilterRuleHandler::end(const QStringRef&, const QStringRef&) {
   return true;
 }
 
 StateHandler* BorrowersHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(localName_ == QLatin1String("borrower")) {
     return new BorrowerHandler(d);
   }
   return nullptr;
 }
 
 bool BorrowersHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes&) {
   return true;
 }
 
 bool BorrowersHandler::end(const QStringRef&, const QStringRef&) {
   return true;
 }
 
 StateHandler* BorrowerHandler::nextHandlerImpl(const QStringRef&, const QStringRef& localName_) {
   if(localName_ == QLatin1String("loan")) {
     return new LoanHandler(d);
   }
   return nullptr;
 }
 
 bool BorrowerHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes& atts_) {
   QString name = attValue(atts_, "name");
   QString uid = attValue(atts_, "uid");
   d->borrower = new Data::Borrower(name, uid);
 
   return true;
 }
 
 bool BorrowerHandler::end(const QStringRef&, const QStringRef&) {
   if(d->coll && !d->borrower->isEmpty()) {
     d->coll->addBorrower(d->borrower);
   }
   d->borrower = Data::BorrowerPtr();
   return true;
 }
 
 bool LoanHandler::start(const QStringRef&, const QStringRef&, const QXmlStreamAttributes& atts_) {
   m_id = attValue(atts_, "entryRef").toInt();
   m_uid = attValue(atts_, "uid");
   m_loanDate = attValue(atts_, "loanDate");
   m_dueDate = attValue(atts_, "dueDate");
   m_inCalendar = atts_.value(QLatin1String("calendar")) == QLatin1String("true");
   return true;
 }
 
 bool LoanHandler::end(const QStringRef&, const QStringRef&) {
   Data::EntryPtr entry = d->coll->entryById(m_id);
   if(!entry) {
     myWarning() << "no entry with id = " << m_id;
     return true;
   }
   QDate loanDate, dueDate;
   if(!m_loanDate.isEmpty()) {
     loanDate = QDate::fromString(m_loanDate, Qt::ISODate);
   }
   if(!m_dueDate.isEmpty()) {
     dueDate = QDate::fromString(m_dueDate, Qt::ISODate);
   }
 
   Data::LoanPtr loan(new Data::Loan(entry, loanDate, dueDate, d->text));
   loan->setUID(m_uid);
   loan->setInCalendar(m_inCalendar);
   d->borrower->addLoan(loan);
   return true;
 }