Add UnavailableDataset as a default dataset for lite mode (#2083)

* sync remote

* fallback dataset for lite

* update file permissions

* update release note

* fix tests

RELEASE.md

@@ -16,6 +16,7 @@ Please follow the established format:
 
 - Fixes design issues in metadata panel. (#2009)
 - Fix missing run command in metadata panel for task nodes. (#2055)
+- Add `UnavailableDataset` as a default dataset for `--lite` mode. (#2083)
 
 # Release 9.2.0
 

package/kedro_viz/api/rest/responses.py

@@ -144,7 +144,7 @@ class DataNodeMetadataAPIResponse(BaseAPIResponse):
 
 
 class TranscodedDataNodeMetadataAPIReponse(BaseAPIResponse):
-    filepath: str
+    filepath: Optional[str] = None
     original_type: str
     transcoded_types: List[str]
     run_command: Optional[str] = None

package/kedro_viz/data_access/managers.py

@@ -8,12 +8,12 @@
 import networkx as nx
 from kedro.io import DataCatalog
 from kedro.io.core import DatasetError
-from kedro.io.memory_dataset import MemoryDataset
 from kedro.pipeline import Pipeline as KedroPipeline
 from kedro.pipeline.node import Node as KedroNode
 from sqlalchemy.orm import sessionmaker
 
 from kedro_viz.constants import DEFAULT_REGISTERED_PIPELINE_ID, ROOT_MODULAR_PIPELINE_ID
+from kedro_viz.integrations.utils import UnavailableDataset
 from kedro_viz.models.flowchart import (
     DataNode,
     GraphEdge,
@@ -325,9 +325,7 @@ def add_dataset(
             # Kedro Viz in lite mode. The `get_dataset` function
             # of DataCatalog calls AbstractDataset.from_config
             # which tries to create a Dataset instance from the pattern
-
-            # pylint: disable=abstract-class-instantiated
-            obj = MemoryDataset()  # type: ignore[abstract]
+            obj = UnavailableDataset()
 
         layer = self.catalog.get_layer_for_dataset(dataset_name)
         graph_node: Union[DataNode, TranscodedDataNode, ParametersNode]

package/kedro_viz/integrations/kedro/data_catalog_lite.py

@@ -7,7 +7,8 @@
 
 from kedro.io.core import AbstractDataset, DatasetError, generate_timestamp
 from kedro.io.data_catalog import DataCatalog, _resolve_credentials
-from kedro.io.memory_dataset import MemoryDataset
+
+from kedro_viz.integrations.utils import UnavailableDataset
 
 
 class DataCatalogLite(DataCatalog):
@@ -54,11 +55,9 @@ def from_config(
                             ds_name, ds_config, load_versions.get(ds_name), save_version
                         )
                     except DatasetError:
-                        # pylint: disable=abstract-class-instantiated
-                        datasets[ds_name] = MemoryDataset()  # type: ignore[abstract]
+                        datasets[ds_name] = UnavailableDataset()
             except KeyError:
-                # pylint: disable=abstract-class-instantiated
-                datasets[ds_name] = MemoryDataset()  # type: ignore[abstract]
+                datasets[ds_name] = UnavailableDataset()
 
         sorted_patterns = cls._sort_patterns(dataset_patterns)
         if sorted_patterns:

package/kedro_viz/integrations/kedro/data_loader.py

@@ -23,30 +23,11 @@
 from kedro_viz.constants import VIZ_METADATA_ARGS
 from kedro_viz.integrations.kedro.data_catalog_lite import DataCatalogLite
 from kedro_viz.integrations.kedro.lite_parser import LiteParser
+from kedro_viz.integrations.utils import _VizNullPluginManager
 
 logger = logging.getLogger(__name__)
 
 
-class _VizNullPluginManager:
-    """This class creates an empty ``hook_manager`` that will ignore all calls to hooks
-    and registered plugins allowing the runner to function if no ``hook_manager``
-    has been instantiated.
-
-    NOTE: _VizNullPluginManager is a clone of _NullPluginManager class in Kedro.
-    This was introduced to support the earliest version of Kedro which does not
-    have _NullPluginManager defined
-    """
-
-    def __init__(self, *args, **kwargs):
-        pass
-
-    def __getattr__(self, name):
-        return self
-
-    def __call__(self, *args, **kwargs):
-        pass
-
-
 def _get_dataset_stats(project_path: Path) -> Dict:
     """Return the stats saved at stats.json as a dictionary if found.
     If not, return an empty dictionary

package/kedro_viz/integrations/utils.py

@@ -0,0 +1,54 @@
+"""`kedro_viz.integrations.utils` provides utility functions and classes
+to integrate Kedro-Viz with external data sources.
+"""
+
+from typing import Any, Union
+
+from kedro.io.core import AbstractDataset
+
+_EMPTY = object()
+
+
+class _VizNullPluginManager:  # pragma: no cover
+    """This class creates an empty ``hook_manager`` that will ignore all calls to hooks
+    and registered plugins allowing the runner to function if no ``hook_manager``
+    has been instantiated.
+
+    NOTE: _VizNullPluginManager is a clone of _NullPluginManager class in Kedro.
+    This was introduced to support the earliest version of Kedro which does not
+    have _NullPluginManager defined
+    """
+
+    def __init__(self, *args, **kwargs):
+        pass
+
+    def __getattr__(self, name):
+        return self
+
+    def __call__(self, *args, **kwargs):
+        pass
+
+
+class UnavailableDataset(AbstractDataset):  # pragma: no cover
+    """This class is a custom dataset implementation for `Kedro Viz Lite`
+    when kedro-datasets are unavailable"""
+
+    def __init__(
+        self,
+        data: Any = _EMPTY,
+        metadata: Union[dict[str, Any], None] = None,
+    ):
+        self._data = data
+        self.metadata = metadata
+
+    def load(self, *args, **kwargs):
+        pass
+
+    def save(self, *args, **kwargs):
+        pass
+
+    def _exists(self):
+        pass
+
+    def _describe(self) -> dict[str, Any]:
+        return {"data": self._data}

package/tests/test_data_access/test_managers.py

@@ -14,6 +14,7 @@
 from kedro_viz.data_access.repositories.modular_pipelines import (
     ModularPipelinesRepository,
 )
+from kedro_viz.integrations.utils import UnavailableDataset
 from kedro_viz.models.flowchart import (
     DataNode,
     GraphEdge,
@@ -381,7 +382,7 @@ def test_add_dataset_with_unresolved_pattern(
                 "my_pipeline", dataset_name, example_modular_pipelines_repo_obj
             )
 
-        assert isinstance(dataset_obj.kedro_obj, MemoryDataset)
+        assert isinstance(dataset_obj.kedro_obj, UnavailableDataset)
 
     def test_add_all_parameters(
         self,

src/components/metadata/metadata.js

@@ -206,6 +206,7 @@ const MetaData = ({
                 <MetaDataRow
                   label="File Path:"
                   kind="path"
+                  empty="N/A"
                   value={removeInitialSlash(metadata.filepath)}
                 />
                 {hasTrackingData && (

src/components/metadata/metadata.test.js

@@ -504,7 +504,7 @@ describe('MetaData', () => {
         mockMetadata: nodeParameters,
       });
       const row = rowByLabel(wrapper, 'File Path:');
-      expect(textOf(rowValue(row))).toEqual(['-']);
+      expect(textOf(rowValue(row))).toEqual(['N/A']);
     });
 
     it('shows the first line (number of parameters) displayed in json viewer for parameter object', () => {