Introduce ReviewStep block and allow adding it to new mentoring

block (step builder).

problem_builder/__init__.py

 from .mentoring import MentoringBlock, MentoringWithExplicitStepsBlock
-from .step import MentoringStepBlock
+from .step import MentoringStepBlock, ReviewStepBlock
 from .answer import AnswerBlock, AnswerRecapBlock
 from .choice import ChoiceBlock
 from .dashboard import DashboardBlock

problem_builder/mentoring.py

@@ -905,9 +905,10 @@ class MentoringWithExplicitStepsBlock(BaseMentoringBlock, StudioContainerWithNes
         NestedXBlockSpec allows explicitly setting disabled/enabled state, disabled reason (if any) and single/multiple
         instances
         """
-        from .step import MentoringStepBlock  # Import here to avoid circular dependency
+        from .step import MentoringStepBlock, ReviewStepBlock  # Import here to avoid circular dependency
         return [
             MentoringStepBlock,
+            ReviewStepBlock,
             NestedXBlockSpec(CompletedMentoringMessageShim, boilerplate='completed'),
             NestedXBlockSpec(IncompleteMentoringMessageShim, boilerplate='incomplete'),
             NestedXBlockSpec(MaxAttemptsReachedMentoringMessageShim, boilerplate='max_attempts_reached'),

problem_builder/step.py

@@ -207,3 +207,28 @@ class MentoringStepBlock(
         fragment.initialize_js('MentoringStepBlock')
 
         return fragment
+
+
+class ReviewStepBlock(XBlockWithPreviewMixin, XBlock):
+    """ A dedicated step for reviewing results for a mentoring block """
+    CATEGORY = 'sb-review-step'
+    STUDIO_LABEL = _("Review Step")
+
+    display_name = String(
+        default="Review Step"
+    )
+
+    def mentoring_view(self, context=None):
+        """ Mentoring View """
+        return self._render_view(context)
+
+    def student_view(self, context=None):
+        """ Student View """
+        return self._render_view(context)
+
+    def _render_view(self, context):
+        fragment = Fragment()
+        fragment.add_content(loader.render_template('templates/html/review_step.html', {
+            'self': self,
+        }))
+        return fragment

problem_builder/templates/html/review_step.html

+<div class="sb-review-step">
+
+  <h3>...</h3>
+
+</div>

setup.py

@@ -43,6 +43,7 @@ BLOCKS = [
     'problem-builder = problem_builder:MentoringBlock',
     'step-builder = problem_builder:MentoringWithExplicitStepsBlock',
     'sb-step = problem_builder:MentoringStepBlock',
+    'sb-review-step = problem_builder:ReviewStepBlock',
 
     'pb-table = problem_builder:MentoringTableBlock',
     'pb-column = problem_builder:MentoringTableColumn',