WIP: implement nodes download endpoint

aiida_restapi/routers/nodes.py

@@ -7,6 +7,7 @@
 from aiida.common.exceptions import EntryPointError
 from aiida.plugins.entry_point import load_entry_point
 from fastapi import APIRouter, Depends, File, HTTPException
+from fastapi.responses import StreamingResponse
 
 from aiida_restapi import models
 
@@ -38,6 +39,56 @@ async def read_node(nodes_id: int) -> Optional[models.Node]:
     return qbobj.dict()[0]['node']
 
 
+@router.get('/nodes/{nodes_id}/download?download_format={download_format}', response_model=StreamingResponse)
+@with_dbenv()
+async def download_node(nodes_id: int, download_format: str | None = None) -> Optional[models.Node]:
+    """Get nodes by id."""
+    qbobj = orm.QueryBuilder()
+    qbobj.append(orm.Node, filters={'id': nodes_id}, project='**', tag='node').limit(1)
+    node = qbobj.dict()[0]['node']
+
+    # TODO that is the behavior in the old REST API but I think we should rather send error message
+    #      since it does not agree with the response_model
+    if len(node) == 0:
+        return {}
+        # raise HTTPException(status_code=404, detail=f"Could no find any node with id {nodes_id}")
+
+    if download_format is None:
+        raise RestInputValidationError(
+            'Please specify the download format. '
+            'The available download formats can be '
+            'queried using the /nodes/download_formats/ endpoint.'
+        )
+
+    elif download_format in node.get_export_formats():
+        # byteobj, dict with {filename: filecontent}
+        import io
+
+        bytes, metadata = node._exportcontent(download_format)[0]
+        return StreamingResponse(
+            io.BytesIO(bytes)
+        )  # , media_type=next(iter(medata.values()))) # Don. know what metadata contains, but could be maybe used to define media_type
+        # try:
+        #    response['data'] =
+        #    response['status'] = 200
+        #    try:
+        #        response['filename'] = node.filename
+        #    except AttributeError:
+        #        response['filename'] = f'{node.uuid}.{download_format}'
+        # except LicensingException as exc:
+        #    response['status'] = 500
+        #    response['data'] = str(exc)
+
+        # return response
+
+    else:
+        raise RestInputValidationError(
+            'The format {} is not supported. '
+            'The available download formats can be '
+            'queried using the /nodes/download_formats/ endpoint.'.format(download_format)
+        )
+
+
 @router.post('/nodes', response_model=models.Node)
 @with_dbenv()
 async def create_node(

docs/source/user_guide/graphql.md

@@ -377,7 +377,7 @@ NOT YET SPECIFICALLY IMPLEMENTED
 http://localhost:5000/api/v4/nodes/download_formats
 ```
 
-NOT YET IMPLEMENTED
+Not implemented for GraphQL, please adapt the URL for this use case.
 
 
 ```html

tests/test_nodes.py

@@ -285,3 +285,11 @@ def test_create_bool_with_extra(client, authenticate):  # pylint: disable=unused
     assert check_response.status_code == 200, response.content
     assert check_response.json()['extras']['extra_one'] == 'value_1'
     assert check_response.json()['extras']['extra_two'] == 'value_2'
+
+
+ def test_get_download_node(default_nodes, client):
+    """Test get projectable properites for nodes."""
+
+    for nodes_id in default_nodes:
+        response = client.get(f'/nodes/{nodes_id}/download?download_format=cif') #TODO download_format is wrong need to check this
+        assert response.status_code == 200