ENH: Allow required value in reportlet configs.

nireports/assembler/report.py

@@ -36,6 +36,7 @@
 
 from nireports.assembler import data
 from nireports.assembler.reportlet import Reportlet
+from nireports.exceptions import NiReportsException, ReportletException
 
 # Add a new figures spec
 try:
@@ -339,6 +340,7 @@ def index(self, config):
 
         This method also places figures in their final location.
         """
+        exceptions = []
         # Initialize a BIDS layout
         _indexer = BIDSLayoutIndexer(
             config_filename=data.load("nipreps.json"),
@@ -361,22 +363,25 @@ def index(self, config):
             orderings = [s for s in subrep_cfg.get("ordering", "").strip().split(",") if s]
             entities, list_combos = self._process_orderings(orderings, layout.get(**bids_filters))
 
+            reportlets = []
+
             if not list_combos:  # E.g. this is an anatomical reportlet
-                reportlets = [
-                    Reportlet(
-                        layout,
-                        config=cfg,
-                        out_dir=out_dir,
-                        bids_filters=bids_filters,
-                        metadata=metadata,
-                    )
-                    for cfg in subrep_cfg["reportlets"]
-                ]
+                for cfg in subrep_cfg["reportlets"]:
+                    try:
+                        rlet = Reportlet(
+                            layout,
+                            config=cfg,
+                            out_dir=out_dir,
+                            bids_filters=bids_filters,
+                            metadata=metadata,
+                        )
+                        reportlets.append(rlet)
+                    except ReportletException as e:
+                        exceptions.append(e)
                 list_combos = subrep_cfg.get("nested", False)
             else:
                 # Do not use dictionary for queries, as we need to preserve ordering
                 # of ordering columns.
-                reportlets = []
                 for c in list_combos:
                     # do not display entities with the value None.
                     c_filt = [
@@ -389,20 +394,30 @@ def index(self, config):
 
                     for cfg in subrep_cfg["reportlets"]:
                         cfg["bids"].update({entities[i]: c[i] for i in range(len(c))})
-                        rlet = Reportlet(
-                            layout,
-                            config=cfg,
-                            out_dir=out_dir,
-                            bids_filters=bids_filters,
-                            metadata=metadata,
-                        )
-                        if not rlet.is_empty():
-                            rlet.title = title
-                            title = None
-                            reportlets.append(rlet)
+                        try:
+                            rlet = Reportlet(
+                                layout,
+                                config=cfg,
+                                out_dir=out_dir,
+                                bids_filters=bids_filters,
+                                metadata=metadata,
+                            )
+                            if not rlet.is_empty():
+                                rlet.title = title
+                                title = None
+                                reportlets.append(rlet)
+                        except ReportletException as e:
+                            exceptions.append(e)
 
             # Filter out empty reportlets
             reportlets = [r for r in reportlets if not r.is_empty()]
+
+            # When support python < 3.11 dropped we can use ExceptionGroups
+            if exceptions:
+                raise NiReportsException(
+                    ("There were errors generating report {self}", *exceptions)
+                )
+
             if reportlets:
                 sub_report = SubReport(
                     subrep_cfg["name"],
@@ -445,6 +460,9 @@ def process_plugins(self, config, metadata=None):
                     ],
                 )
 
+    def __str__(self):
+        return f"<Report {self.title}>"
+
     def generate_report(self):
         """Once the Report has been indexed, the final HTML can be generated"""
         env = jinja2.Environment(

nireports/assembler/reportlet.py

@@ -32,6 +32,7 @@
 
 from nireports.assembler import data
 from nireports.assembler.misc import dict2html, read_crashfile
+from nireports.exceptions import RequiredReportletException
 
 IMG_SNIPPET = """\
 <div class="reportlet">
@@ -446,6 +447,9 @@ def __init__(self, layout, config=None, out_dir=None, bids_filters=None, metadat
                     boiler_tabs.append("</ul>")
                     self.components.append(("\n".join(boiler_tabs + boiler_body), desc_text))
 
+        if config.get("required", False) and self.is_empty():
+            raise RequiredReportletException(config)
+
     def is_empty(self):
         """Determine whether the reportlet has no components."""
         return len(self.components) == 0

nireports/assembler/tests/test_report.py

@@ -36,6 +36,7 @@
 
 from nireports.assembler import data
 from nireports.assembler.report import Report
+from nireports.exceptions import NiReportsException
 
 summary_meta = {
     "Summary": {
@@ -141,6 +142,19 @@ def test_report2(bids_sessions):
     )
 
 
+def test_missing_reportlet(test_report1, bids_sessions):
+    out_dir = tempfile.mkdtemp()
+    report = test_report1
+    settings = yaml.safe_load(data.load.readable("default.yml").read_text())
+    settings["root"] = str(Path(bids_sessions) / "nireports")
+    settings["out_dir"] = str(Path(out_dir) / "nireports")
+    settings["run_uuid"] = "fakeuuid"
+    settings["sections"][0]["reportlets"][0]["required"] = True
+    settings["sections"][0]["reportlets"][0]["bids"] = {"datatype": "fake"}
+    with pytest.raises(NiReportsException, match="No content found"):
+        report.index(settings)
+
+
 @pytest.mark.parametrize(
     "orderings,expected_entities,expected_value_combos",
     [

nireports/exceptions.py

@@ -0,0 +1,37 @@
+# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
+# vi: set ft=python sts=4 ts=4 sw=4 et:
+#
+# Copyright 2024 The NiPreps Developers <[email protected]>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# We support and encourage derived works from this project, please read
+# about our expectations at
+#
+#     https://www.nipreps.org/community/licensing/
+#
+"""Exceptions issued by the assembler."""
+
+class NiReportsException(Exception):
+    pass
+
+
+class ReportletException(NiReportsException):
+    pass
+
+
+class RequiredReportletException(ReportletException):
+    def __init__(self, config):
+        message = (f"No content found while generated reportlet listed as required with the"
+        f"following config: {config}")
+        self.args = (message)