Skip to main content

DataDictionary

id: py-DataDictionary​

DataDictionary

The DataDictionary provides access to all data structures defined in your layline.io project — message types, record formats, and field definitions. It is available globally as dataDictionary in every Python processor.

Use it to create new messages, navigate type hierarchies, and access field metadata.

At a Glance​

# Navigate to a specific type
detail_type = dataDictionary.type.MyFormat.Detail

# Create a new message from that type
new_message = dataDictionary.createMessage(detail_type)

# Populate and emit
new_message.data.RECORD_TYPE = "D"
stream.emit(new_message, OUTPUT_PORT)

Properties​

PropertyTypeDescription
typeDataDictionaryTypesAccess all data dictionary types defined in your project

type​

Navigate your data dictionary hierarchy through this property. The structure mirrors your project's format and data dictionary definitions.

# Access a specific record type
header_type = dataDictionary.type.MyFormat.Header
detail_type = dataDictionary.type.MyFormat.Detail

# Access nested fields (returns DataDictionaryEntity for use with Message methods)
record_type_field = dataDictionary.type.MyFormat.Detail.RECORD_TYPE
name_field       = dataDictionary.type.MyFormat.Detail.NAME

# Use with Message getters/setters
name = message.getString(name_field)

Methods​

createMessage(entity)​

Creates a new Message from a data dictionary structure. Use this when you need to construct messages for splitting, aggregation, or transformation.

ParameterTypeDescription
entityDataDictionaryEntityThe data dictionary path to the structure you want to instantiate

Returns: Message

# Create a message from a specific type
header = dataDictionary.createMessage(dataDictionary.type.MyFormat.Header)

# Populate fields
header.data.RECORD_TYPE = "HDR"
header.data.TIMESTAMP   = DateTime.now()

# Emit
stream.emit(header, OUTPUT_PORT)

See Also​

Last updated on