About

A DataDescriptionDefinition represents the "raw" description of data attributes. Such a definition is stored e.g. in a static file and loaded by Cinema 4D. The description definition is the base for the final, "resolved" data description, see DataDescription Manual.

Description

General information (maxon::DESCRIPTION::DATA::INFO) is accessed with:

maxon::DataDescriptionDefinitionInterface::GetInfo(): Returns the info dictionary.
maxon::DataDescriptionDefinitionInterface::SetInfo(): Sets the info dictionary.

The various attribute descriptions in the definition are stored as DataDictionaries (using the alias maxon::DataDescriptionEntry):

maxon::DataDescriptionDefinitionInterface::GetEntryCount(): Returns the number of stored entries.
maxon::DataDescriptionDefinitionInterface::GetEntries(): Returns all entries.
maxon::DataDescriptionDefinitionInterface::GetEntry(): Returns the entry at the given index.
maxon::DataDescriptionDefinitionInterface::AddEntry(): Adds an entry to the definition.
maxon::DataDescriptionDefinitionInterface::ReplaceEntry(): Replaces the entry at the given index.
maxon::DataDescriptionDefinitionInterface::EraseEntry(): Deletes the entry at the given index.
maxon::DataDescriptionDefinitionInterface::Reset(): Deletes all entries.

Usable observables are:

ObservableDescriptionChanged: Is fired on any change of the definition.

  // This example loads the data description definition of the given data type.
 
  // data type ID
  const maxon::IdAndVersion dataType = { "net.maxonexample.class.descriptionElement", maxon::Id() };
 
  // load data description definition
  const maxon::Id                  category = maxon::DATADESCRIPTION_CATEGORY_DATA;
  const maxon::LanguageRef         language = maxon::LanguageRef::Create() iferr_return;
  const maxon::LOADDESCRIPTIONMODE mode = maxon::LOADDESCRIPTIONMODE::COMPLETE;
  maxon::DataDescriptionDefinition definition = maxon::DataDescriptionDefinitionDatabaseInterface::LoadDescription(mode, category, language, dataType) iferr_return;
 
  // get all attributes
  const auto attributes = definition.GetEntries() iferr_return;
 
  // list all attributes
  for (auto& attribute : attributes)
  {
    const maxon::InternedId ID = attribute.Get(maxon::DESCRIPTION::BASE::IDENTIFIER) iferr_return;
    const maxon::Id         attributeDataType = attribute.Get(maxon::DESCRIPTION::DATA::BASE::DATATYPE) iferr_return;
    const maxon::Data       defaultData = attribute.Get(maxon::DESCRIPTION::DATA::BASE::DEFAULTVALUE) iferr_return;
 
    DiagnosticOutput("Attribute \"@\" of type @. Default value: @", ID, attributeDataType, defaultData);
  }

Database

DataDescriptionDefinitions are stored in databases. These databases are managed with maxon::DataDescriptionDefinitionDatabaseInterface.

Description definition databases can be stored in JSON files. These files are loaded with RegisterDatabaseWithUrl().

The databases are accessed with:

maxon::DataDescriptionDefinitionDatabaseInterface::RegisterDatabaseWithUrl(): Loads a database from the given maxon::Url.
maxon::DataDescriptionDefinitionDatabaseInterface::RegisterDatabase(): Registers a special database.
maxon::DataDescriptionDefinitionDatabaseInterface::GetRegisteredDatabases(): Returns the IDs of all registered databases.
maxon::DataDescriptionDefinitionDatabaseInterface::WriteDataBases(): Save all databases to file.
maxon::DataDescriptionDefinitionDatabaseInterface::QueryNeedsWriteDataBases(): Returns true if changes to the databases are pending and not saved.

For an example see Loading Data Descriptions.

The descriptions stored in the databases are accessed with:

maxon::DataDescriptionDefinitionDatabaseInterface::LoadDescription(): Loads the description definition of the given data type.
maxon::DataDescriptionDefinitionDatabaseInterface::StoreDescription(): Stores the description definition of the given data type in the given database.
maxon::DataDescriptionDefinitionDatabaseInterface::DeleteDescription(): Deletes the description definition of the given data type.
maxon::DataDescriptionDefinitionDatabaseInterface::GetRegisteredDescriptions(): Returns all description definitions of the given database or all databases.

A stored description definition can be updated with:

maxon::DataDescriptionDefinitionDatabaseInterface::UpdateDescription(): Updates the description definition of the given data type.
maxon::DataDescriptionDefinitionDatabaseInterface::UpdateDescriptionI(): Updates the description definition of the given data type.

It is possible to directly access attributes stored in the description definitions:

maxon::DataDescriptionDefinitionDatabaseInterface::RenameId(): Renames the given ID in all databases.
maxon::DataDescriptionDefinitionDatabaseInterface::RenameAttribute(): Renames the given attribute in all databases.
maxon::DataDescriptionDefinitionDatabaseInterface::CheckUniqueAttributeName(): Returns true if the given ID is unique in all databases.

A callback function can be registered:

maxon::DataDescriptionDefinitionDatabaseInterface::RegisterMessage(): Registers the callback functions for the given data type and attribute.
maxon::DataDescriptionDefinitionDatabaseInterface::FindNodeMessage(): Returns the callback function for the given data type and attribute.

Table of Contents

About

Description

Database

Further Reading