dynamically construct crispy layout in graphs plot

scipost_django/graphs/forms.py

@@ -8,7 +8,8 @@ from graphs.graphs.plotter import ModelFieldPlotter
 
 from .graphs import ALL_PLOTTERS, ALL_PLOT_KINDS, AVAILABLE_MPL_THEMES
 
-import matplotlib.pyplot as plt
+from crispy_forms.helper import FormHelper, Layout
+from crispy_forms.layout import Div, Field
 
 
 class ModelFieldPlotterSelectForm(forms.Form):
@@ -92,6 +93,51 @@ class PlotOptionsForm(forms.Form):
             self.fields.update(self.plot_kind_select_form.fields)
             self.fields.update(self.generic_plot_options_form.fields)
 
+        self.helper = FormHelper()
+        self.helper.layout = Layout()
+
+        def get_layout_field_names(layout):
+            """Recurse through a layout to get all field names."""
+            field_names = []
+            for field in layout:
+                if isinstance(field, str):
+                    field_names.append(field)
+                else:
+                    field_names.extend(get_layout_field_names(field.fields))
+            return field_names
+
+        # Iterate over all forms and construct the form layout
+        # either by extending the layout with the preferred layout from the object class
+        # or by creating a row with all fields that are not already in the layout
+        for form, object_class in {
+            self.model_field_select_form: self.model_field_select_form.plotter.__class__,
+            self.plot_kind_select_form: self.plot_kind_select_form.kind_class,
+            self.generic_plot_options_form: None,
+        }.items():
+
+            layout = Layout()
+            if object_class not in (None, None.__class__):
+                principal_field_name = next(iter(form.fields.keys()))
+                layout.append(Div(Field(principal_field_name), css_class="col-12"))
+
+                row_constructor = getattr(
+                    object_class, "get_plot_options_form_layout_row_content"
+                )
+                if row_constructor:
+                    layout.extend(row_constructor())
+
+            layout.extend(
+                [
+                    Div(Field(field_name), css_class="col-12")
+                    for field_name in form.fields.keys()
+                    if field_name not in get_layout_field_names(layout)
+                ],
+            )
+
+            self.helper.layout.append(layout)
+
+        self.helper.all().wrap(Div, css_class="row")
+
     def clean(self):
         cleaned_data = super().clean()
 

scipost_django/graphs/graphs/plotkind.py

@@ -7,6 +7,7 @@ from matplotlib.figure import Figure
 import pandas as pd
 
 from .options import BaseOptions
+from crispy_forms.layout import Layout, Div, Field
 
 from typing import TYPE_CHECKING, Any
 
@@ -69,10 +70,23 @@ class PlotKind:
         ax = fig.add_subplot(111)
         ax.set_title(f"{self.get_name()} plot of {self.plotter.model.__name__}")
 
-        x, y = self.get_data()
-        ax.plot(x, y)
+        try:
+            x, y = self.get_data()
+            ax.plot(x, y)
+        except ValueError as e:
+            self.display_plotting_error(ax)
+
         return fig
 
+    def display_plotting_error(self, ax):
+        ax.text(0.5, 0.5, f"No data to plot", ha="center", va="center")
+        ax.grid(False)
+        ax.axis("off")
+
+    @classmethod
+    def get_plot_options_form_layout_row_content(cls):
+        return Div()
+
 
 class TimelinePlot(PlotKind):
     name = "timeline"
@@ -124,6 +138,38 @@ class TimelinePlot(PlotKind):
             widget=forms.DateTimeInput(attrs={"type": "date"}),
         )
 
+    @classmethod
+    def get_plot_options_form_layout_row_content(cls):
+        layout = Layout(
+            Div(Field("y_key"), css_class="col-12"),
+            Div(Field("x_lim_min"), css_class="col-6"),
+            Div(Field("x_lim_max"), css_class="col-6"),
+        )
+
+        # Prefix every field in the layout with the prefix
+        def prefix_field(field):
+            """
+            Recursively prefix the fields in a layout.
+            Return type is irrelevant, as it modifies the argument directly.
+            """
+            contained_fields = getattr(field, "fields", None)
+            if contained_fields is None:
+                return
+
+            # If the crispy field is a Field type with a single string identifier, prefix it
+            if (
+                isinstance(field, Field)
+                and len(contained_fields) == 1
+                and isinstance(field_key := contained_fields[0], str)
+            ):
+                field.fields = [cls.Options.prefix + field_key]
+            else:
+                return [prefix_field(f) for f in contained_fields]
+
+        prefix_field(layout)
+
+        return layout
+
 
 class MapPlot(PlotKind):
     name = "map"

scipost_django/graphs/graphs/plotter.py

@@ -19,6 +19,8 @@ from submissions.models import Report, Submission
 
 from .options import BaseOptions
 
+from crispy_forms.layout import Div
+
 OptionDict = dict[str, Any]
 
 if TYPE_CHECKING:
@@ -80,10 +82,15 @@ class ModelFieldPlotter(ABC):
         )
 
         fig = kind.plot()
-        fig.suptitle(options.get("title", None))
+        if title := options.get("title", None):
+            fig.axes[0].set_title(title)
 
         return fig
 
+    @classmethod
+    def get_plot_options_form_layout_row_content(cls):
+        return Div()
+
 
 class PublicationPlotter(ModelFieldPlotter):
     model = Publication