gooddata

GoodData Apache Ossie Converter

Bidirectional converter between GoodData's declarative Logical Data Model (LDM) and the Apache Ossie semantic model specification.

Features

• GoodData → Ossie: Convert a GoodData declarative LDM JSON to Ossie semantic model YAML
• Ossie → GoodData: Convert an Ossie semantic model YAML to GoodData declarative LDM JSON
• Preserves GoodData-specific metadata (labels, date granularities, geo types) via Ossie custom_extensions
• Generates dual-dialect expressions (ANSI_SQL + MAQL) for fields

Usage

import json
import yaml
from ossie_gooddata import gooddata_to_osi, osi_to_gooddata
from ossie_gooddata.models import gd_model_from_dict, gd_model_to_dict

# GoodData → Apache Ossie
with open("gooddata_ldm.json") as f:
    gd_model = gd_model_from_dict(json.load(f))
osi_model = gooddata_to_osi(gd_model, model_name="my_model")
with open("osi_model.yaml", "w") as f:
    yaml.dump(osi_model, f, default_flow_style=False)

# Apache Ossie → GoodData
with open("osi_model.yaml") as f:
    osi_data = yaml.safe_load(f)
gd_model = osi_to_gooddata(osi_data, data_source_id="my_datasource")
with open("gooddata_ldm.json", "w") as f:
    json.dump(gd_model_to_dict(gd_model), f, indent=2)

Development

uv sync --group dev
uv run pytest

Concept Mapping

GoodData LDM	Ossie Semantic Model
Dataset	Dataset
Attribute (+ Labels)	Field with dimension metadata
Fact	Field without dimension metadata
Source column data type	Field datatype
Reference (FK)	Relationship
Date Instance	Dataset with GOODDATA custom_extension (date_dimension: true)
MAQL expression	Dialect entry (dialect: MAQL)

Data Types

GoodData source type	Ossie DataType
STRING	String
INT	Integer
NUMERIC	Decimal
BOOLEAN	Boolean
DATE	Date
TIMESTAMP	DateTime
TIMESTAMP_TZ	DateTimeTz

Only an explicitly present GoodData sourceColumnDataType becomes an Ossie datatype. If GoodData omits the source type, the Ossie datatype remains unspecified rather than being inferred from whether the field is an attribute or fact.

Unknown GoodData source types become Opaque and their exact value is retained in a GOODDATA custom extension for lossless round trips. Regular GoodData attributes remain explicitly non-time dimensions even when their source column has a temporal data type; GoodData date instances continue to carry the time-dimension role.

Limitations

• Metrics are not converted. GoodData metrics use MAQL, a context-aware metric language where dimensionality and filters are applied at report time. The current Ossie metric model is SQL-expression-based and cannot represent this paradigm.
• AggregatedFacts are not yet supported.
• Workspace data filters are not mapped.
• GoodData has only one NUMERIC source type, so exporting Ossie Float loses the distinction between approximate and exact numeric values.
• GoodData has no time-only source type. Ossie Time fields retain the existing attribute or fact default and emit a warning when exported.
• Ossie Opaque fields require an exact GoodData source type in their GOODDATA extension for lossless export; otherwise the role default is used with a warning.