Tag Parser 10.3.1
C++ library for reading and writing MP4 (iTunes), ID3, Vorbis, Opus, FLAC and Matroska tags
fieldbasedtag.h
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1#ifndef TAG_PARSER_FIELDBASEDTAG_H
2#define TAG_PARSER_FIELDBASEDTAG_H
3
4#include "./tag.h"
5
6#include <functional>
7#include <map>
8
9namespace TagParser {
10
17template <typename ImplementationType> class FieldMapBasedTagTraits {
18};
19
31template <class ImplementationType> class FieldMapBasedTag : public Tag {
32 friend class FieldMapBasedTagTraits<ImplementationType>;
33
34public:
38
40
41 TagType type() const;
42 std::string_view typeName() const;
44 const TagValue &value(const IdentifierType &id) const;
45 const TagValue &value(KnownField field) const;
46 std::vector<const TagValue *> values(const IdentifierType &id) const;
47 std::vector<const TagValue *> values(KnownField field) const;
48 bool setValue(const IdentifierType &id, const TagValue &value);
49 bool setValue(KnownField field, const TagValue &value);
50 bool setValues(const IdentifierType &id, const std::vector<TagValue> &values);
51 bool setValues(KnownField field, const std::vector<TagValue> &values);
52 bool hasField(KnownField field) const;
53 bool hasField(const IdentifierType &id) const;
55 const std::multimap<IdentifierType, FieldType, Compare> &fields() const;
56 std::multimap<IdentifierType, FieldType, Compare> &fields();
57 std::size_t fieldCount() const;
60 bool supportsField(KnownField field) const;
63 std::size_t insertFields(const FieldMapBasedTag<ImplementationType> &from, bool overwrite);
64 std::size_t insertValues(const Tag &from, bool overwrite);
66
67protected:
69
71 void internallyGetValuesFromField(const FieldType &field, std::vector<const TagValue *> &values) const;
72 std::vector<const TagValue *> internallyGetValues(const IdentifierType &id) const;
74 bool internallySetValues(const IdentifierType &id, const std::vector<TagValue> &values);
75 bool internallyHasField(const IdentifierType &id) const;
76 // no default implementation: IdentifierType internallyGetFieldId(KnownField field) const;
77 // no default implementation: KnownField internallyGetKnownField(const IdentifierType &id) const;
79
80private:
81 std::multimap<IdentifierType, FieldType, Compare> m_fields;
82};
83
102{
103}
104
105template <class ImplementationType> TagType FieldMapBasedTag<ImplementationType>::type() const
106{
107 return ImplementationType::tagType;
108}
109
110template <class ImplementationType> std::string_view FieldMapBasedTag<ImplementationType>::typeName() const
111{
112 return ImplementationType::tagName;
113}
114
116{
117 return ImplementationType::defaultTextEncoding;
118}
119
124template <class ImplementationType> const TagValue &FieldMapBasedTag<ImplementationType>::internallyGetValue(const IdentifierType &id) const
125{
126 auto i = m_fields.find(id);
127 return i != m_fields.end() ? i->second.value() : TagValue::empty();
128}
129
134template <class ImplementationType>
136 const FieldMapBasedTag<ImplementationType>::FieldType &field, std::vector<const TagValue *> &values) const
137{
138 if (!field.value().isEmpty()) {
139 values.emplace_back(&field.value());
140 }
141}
142
147template <class ImplementationType>
149{
150 auto range = m_fields.equal_range(id);
151 std::vector<const TagValue *> values;
152 for (auto i = range.first; i != range.second; ++i) {
153 static_cast<const ImplementationType *>(this)->internallyGetValuesFromField(i->second, values);
154 }
155 return values;
156}
157
162template <class ImplementationType> inline const TagValue &FieldMapBasedTag<ImplementationType>::value(const IdentifierType &id) const
163{
164 return static_cast<const ImplementationType *>(this)->internallyGetValue(id);
165}
166
167template <class ImplementationType> inline const TagValue &FieldMapBasedTag<ImplementationType>::value(KnownField field) const
168{
169 return value(fieldId(field));
170}
171
176template <class ImplementationType> inline std::vector<const TagValue *> FieldMapBasedTag<ImplementationType>::values(const IdentifierType &id) const
177{
178 return static_cast<const ImplementationType *>(this)->internallyGetValues(id);
179}
180
181template <class ImplementationType> inline std::vector<const TagValue *> FieldMapBasedTag<ImplementationType>::values(KnownField field) const
182{
183 return static_cast<const ImplementationType *>(this)->values(fieldId(field));
184}
185
186template <class ImplementationType> inline bool FieldMapBasedTag<ImplementationType>::setValue(KnownField field, const TagValue &value)
187{
188 return setValue(fieldId(field), value);
189}
190
195template <class ImplementationType> bool FieldMapBasedTag<ImplementationType>::internallySetValue(const IdentifierType &id, const TagValue &value)
196{
197 auto i = m_fields.find(id);
198 if (i != m_fields.end()) { // field already exists -> set its value
199 i->second.setValue(value);
200 } else if (!value.isEmpty()) { // field doesn't exist -> create new one if value is not null
201 m_fields.insert(std::make_pair(id, FieldType(id, value)));
202 } else { // otherwise return false
203 return false;
204 }
205 return true;
206}
207
212template <class ImplementationType>
214{
215 auto valuesIterator = values.cbegin();
216 auto range = m_fields.equal_range(id);
217 // iterate through all specified and all existing values
218 for (; valuesIterator != values.cend() && range.first != range.second; ++valuesIterator) {
219 // replace existing value with non-empty specified value
220 if (!valuesIterator->isEmpty()) {
221 auto &field = range.first->second;
222 field.clearValue();
223 field.setValue(*valuesIterator);
224 ++range.first;
225 }
226 }
227 // add remaining specified values (there are more specified values than existing ones)
228 for (; valuesIterator != values.cend(); ++valuesIterator) {
229 m_fields.insert(std::make_pair(id, FieldType(id, *valuesIterator)));
230 }
231 // remove remaining existing values (there are more existing values than specified ones)
232 for (; range.first != range.second; ++range.first) {
233 range.first->second.clearValue();
234 }
235 return true;
236}
237
242template <class ImplementationType> bool FieldMapBasedTag<ImplementationType>::setValue(const IdentifierType &id, const TagParser::TagValue &value)
243{
244 return static_cast<ImplementationType *>(this)->internallySetValue(id, value);
245}
246
253template <class ImplementationType>
254bool FieldMapBasedTag<ImplementationType>::setValues(const IdentifierType &id, const std::vector<TagValue> &values)
255{
256 return static_cast<ImplementationType *>(this)->internallySetValues(id, values);
257}
258
265template <class ImplementationType> bool FieldMapBasedTag<ImplementationType>::setValues(KnownField field, const std::vector<TagValue> &values)
266{
267 return setValues(fieldId(field), values);
268}
269
270template <class ImplementationType> inline bool FieldMapBasedTag<ImplementationType>::hasField(KnownField field) const
271{
272 return hasField(fieldId(field));
273}
274
279template <class ImplementationType> bool FieldMapBasedTag<ImplementationType>::internallyHasField(const IdentifierType &id) const
280{
281 for (auto range = m_fields.equal_range(id); range.first != range.second; ++range.first) {
282 if (!range.first->second.value().isEmpty()) {
283 return true;
284 }
285 }
286 return false;
287}
288
292template <class ImplementationType> inline bool FieldMapBasedTag<ImplementationType>::hasField(const IdentifierType &id) const
293{
294 return static_cast<const ImplementationType *>(this)->internallyHasField(id);
295}
296
297template <class ImplementationType> inline void FieldMapBasedTag<ImplementationType>::removeAllFields()
298{
299 m_fields.clear();
300}
301
305template <class ImplementationType>
307{
308 return m_fields;
309}
310
314template <class ImplementationType> inline auto FieldMapBasedTag<ImplementationType>::fields() -> std::multimap<IdentifierType, FieldType, Compare> &
315{
316 return m_fields;
317}
318
319template <class ImplementationType> std::size_t FieldMapBasedTag<ImplementationType>::fieldCount() const
320{
321 auto count = std::size_t(0);
322 for (const auto &field : m_fields) {
323 if (!field.second.value().isEmpty()) {
324 ++count;
325 }
326 }
327 return count;
328}
329
334template <class ImplementationType>
336{
337 return static_cast<const ImplementationType *>(this)->internallyGetFieldId(value);
338}
339
344template <class ImplementationType> inline KnownField FieldMapBasedTag<ImplementationType>::knownField(const IdentifierType &id) const
345{
346 return static_cast<const ImplementationType *>(this)->internallyGetKnownField(id);
347}
348
349template <class ImplementationType> inline bool FieldMapBasedTag<ImplementationType>::supportsField(KnownField field) const
350{
351 static IdentifierType def;
352 return fieldId(field) != def;
353}
354
359template <class ImplementationType>
361{
362 return Tag::proposedDataType(knownField(id));
363}
364
368template <class ImplementationType> inline TagDataType FieldMapBasedTag<ImplementationType>::proposedDataType(const IdentifierType &id) const
369{
370 return static_cast<ImplementationType *>(this)->determineProposedDataType(id);
371}
372
379template <class ImplementationType>
381{
382 auto fieldsInserted = std::size_t(0);
383 for (const auto &pair : from.fields()) {
384 const FieldType &fromField = pair.second;
385 if (fromField.value().isEmpty()) {
386 continue;
387 }
388 bool fieldInserted = false;
389 auto range = fields().equal_range(fromField.id());
390 for (auto i = range.first; i != range.second; ++i) {
391 FieldType &ownField = i->second;
392 if ((fromField.isTypeInfoAssigned() && ownField.isTypeInfoAssigned() && fromField.typeInfo() == ownField.typeInfo())
393 || (!fromField.isTypeInfoAssigned() && !ownField.isTypeInfoAssigned())) {
394 if (overwrite || ownField.value().isEmpty()) {
395 ownField = fromField;
396 ++fieldsInserted;
397 }
398 fieldInserted = true;
399 continue;
400 }
401 }
402 if (!fieldInserted) {
403 fields().insert(std::make_pair(fromField.id(), fromField));
404 ++fieldsInserted;
405 }
406 }
407 return fieldsInserted;
408}
409
410template <class ImplementationType> std::size_t FieldMapBasedTag<ImplementationType>::insertValues(const Tag &from, bool overwrite)
411{
412 if (type() == from.type()) {
413 // the tags are of the same type, we can insert the fields directly
414 return insertFields(static_cast<const FieldMapBasedTag<ImplementationType> &>(from), overwrite);
415 } else {
416 return Tag::insertValues(from, overwrite);
417 }
418}
419
421{
422 for (auto &field : fields()) {
423 field.second.value().convertDataEncodingForTag(this);
424 }
425}
426
427} // namespace TagParser
428
429#endif // TAG_PARSER_FIELDBASEDTAG_H
Defines traits for the specified ImplementationType.
Definition: fieldbasedtag.h:17
The FieldMapBasedTag provides a generic implementation of Tag which stores the tag fields using std::...
Definition: fieldbasedtag.h:31
bool hasField(const IdentifierType &id) const
Returns an indication whether the field with the specified id is present.
bool setValue(const IdentifierType &id, const TagValue &value)
Assigns the given value to the field with the specified id.
void ensureTextValuesAreProperlyEncoded()
Ensures the encoding of all assigned text values is supported by the tag by converting the character ...
bool setValue(KnownField field, const TagValue &value)
Assigns the given value to the specified field.
bool hasField(KnownField field) const
Returns an indication whether the specified field is present.
std::vector< const TagValue * > values(KnownField field) const
Returns the values of the specified field.
std::multimap< IdentifierType, FieldType, Compare > & fields()
Returns the fields of the tag by providing direct access to the field map of the tag.
std::vector< const TagValue * > internallyGetValues(const IdentifierType &id) const
Default implementation for values().
typename FieldMapBasedTagTraits< ImplementationType >::Compare Compare
Definition: fieldbasedtag.h:37
std::string_view typeName() const
Returns the type name of the tag as C-style string.
typename FieldMapBasedTagTraits< ImplementationType >::FieldType::IdentifierType IdentifierType
Definition: fieldbasedtag.h:36
const TagValue & value(KnownField field) const
Returns the value of the specified field.
FieldMapBasedTag()
Constructs a new FieldMapBasedTag.
TagTextEncoding proposedTextEncoding() const
Returns the proposed text encoding.
const TagValue & value(const IdentifierType &id) const
Returns the value of the field with the specified id.
void removeAllFields()
Removes all fields from the tag.
const std::multimap< IdentifierType, FieldType, Compare > & fields() const
Returns the fields of the tag by providing direct access to the field map of the tag.
TagDataType proposedDataType(const IdentifierType &id) const
Returns the proposed data type for the field with the specified id.
bool internallySetValues(const IdentifierType &id, const std::vector< TagValue > &values)
Default implementation for setValues().
TagType type() const
Returns the type of the tag as TagParser::TagType.
std::size_t insertFields(const FieldMapBasedTag< ImplementationType > &from, bool overwrite)
Inserts all fields from another tag of the same field type and compare function.
typename FieldMapBasedTagTraits< ImplementationType >::FieldType FieldType
Definition: fieldbasedtag.h:35
TagDataType internallyGetProposedDataType(const IdentifierType &id) const
Default implementation for proposedDataType().
void internallyGetValuesFromField(const FieldType &field, std::vector< const TagValue * > &values) const
Default way to gather values from a field in internallyGetValues().
KnownField knownField(const IdentifierType &id) const
Returns the field for the specified ID.
std::vector< const TagValue * > values(const IdentifierType &id) const
Returns the values of the field with the specified id.
const TagValue & internallyGetValue(const IdentifierType &id) const
Default implementation for value().
bool internallyHasField(const IdentifierType &id) const
Default implementation for hasField().
bool setValues(const IdentifierType &id, const std::vector< TagValue > &values)
Assigns the given values to the field with the specified id.
std::size_t fieldCount() const
Returns the number of present fields.
bool supportsField(KnownField field) const
Returns an indication whether the specified field is supported by the tag.
bool setValues(KnownField field, const std::vector< TagValue > &values)
Assigns the given values to the field with the specified id.
IdentifierType fieldId(KnownField value) const
Returns the ID for the specified field.
std::size_t insertValues(const Tag &from, bool overwrite)
Inserts all compatible values from another Tag.
bool internallySetValue(const IdentifierType &id, const TagValue &value)
Default implementation for setValue().
The TagValue class wraps values of different types.
Definition: tagvalue.h:95
static const TagValue & empty()
Returns a default-constructed TagValue where TagValue::isNull() and TagValue::isEmpty() both return t...
Definition: tagvalue.cpp:958
bool isEmpty() const
Returns whether no or an empty value is assigned.
Definition: tagvalue.h:527
The Tag class is used to store, read and write tag information.
Definition: tag.h:108
virtual std::size_t insertValues(const Tag &from, bool overwrite)
Inserts all compatible values from another Tag.
Definition: tag.cpp:86
virtual TagType type() const
Returns the type of the tag as TagParser::TagType.
Definition: tag.h:149
virtual TagDataType proposedDataType(KnownField field) const
Returns the proposed data type for the specified field as TagDataType.
Definition: tag.h:214
Contains all classes and functions of the TagInfo library.
Definition: aaccodebook.h:10
KnownField
Specifies the field.
Definition: tag.h:42
TagTextEncoding
Specifies the text encoding.
Definition: tagvalue.h:28
TagType
Specifies the tag type.
Definition: tag.h:20
TagDataType
Specifies the data type.
Definition: tagvalue.h:74