Add regex search option for text searches

Allow user to select to use regex search for student form contents
and teacher response. This is done by checking a checkbox by the field.
Implement filter, field and widget that allow selecting between default
search method and a regex search.
Implement simple validation and error handling (also for exercise identifier,
which didn't validate regex) for regex.
Change form styling to use flex, so the checkbox and label can also be
positioned well.

Fix #87

feedback/filters.py

@@ -1,8 +1,11 @@
 import datetime
+import re
+from typing import Optional, Union
 
 from django.db import models
 import django_filters
 from django import forms
+from django.core.exceptions import ValidationError
 from django.utils.translation import gettext_lazy as _
 
 from django_colortag.filters import ColortagIEAndOrFilter
@@ -32,6 +35,17 @@ def is_empty_value(value):
     )
 
 
+def validate_regex(value: str):
+    """Check if the value is a valid regex pattern."""
+    try:
+        re.compile(value)
+    except re.error as exc:
+        raise ValidationError(
+            _("Not a valid regex pattern"),
+            code="invalid"
+        ) from exc
+
+
 class SplitDateTimeRangeWidget(forms.MultiWidget):
     """Add support to get widgets as parameter"""
     # NOTE: 'wants to be' a reimplementation of django_filters.widgets.DateRangeWidget
@@ -156,6 +170,76 @@ def filter(self, qs, value):
         return qs.filter_flags(*value)
 
 
+class ComboTextSearchWidget(forms.MultiWidget):
+    """Widget for displaying a text search field with a checkbox
+    that allows using another search method.
+    The checkbox label and helptext need to be defined through widget
+    attributes 'bool_label' and 'bool_helptext'.
+    """
+    template_name = "feedback/widgets/combo_textsearch_widget.html"
+
+    def __init__(self, attrs=None) -> None:
+        widgets = {
+            'text': forms.TextInput(attrs=attrs),
+            'regex': forms.CheckboxInput(attrs=attrs),
+        }
+        super().__init__(widgets, attrs)
+
+    def decompress(self, value: Optional[tuple[str, bool]]) -> Union[tuple[str, bool], tuple[None, None]]:
+        if value:
+            return value
+        return (None, None)
+
+
+class ComboTextSearchField(forms.MultiValueField):
+    widget = ComboTextSearchWidget
+
+    def __init__(self, *args, **kwargs) -> None:
+        fields = (
+            forms.CharField(required=False),
+            forms.BooleanField(required=False),
+        )
+        kwargs.setdefault('require_all_fields', False)
+        super().__init__(fields, *args, **kwargs)
+
+    def compress(self, data_list: tuple[str, bool]) -> tuple[str, bool]:
+        return data_list
+
+    def validate(self, value: tuple[str, bool]) -> None:
+        """Validate field value, especially when regex search is used.
+        If an another search method is used as alternative instead of
+        regex or iregex, this method should be overwritten.
+        """
+        super().validate(value)
+        # if regex search is selected, check that string is valid regex
+        if value[1]:
+            validate_regex(value[0])
+
+
+class ComboTextSearchFilter(django_filters.CharFilter):
+    """Text search filter that supports two different search methods.
+    By default, the filter uses the filter_text method of the queryset.
+    However, if the checkbox is selected, uses alternative method for
+    searching (which is by default case-insensitive regex search).
+    """
+    field_class = ComboTextSearchField
+
+    def __init__(self, *args, lookup_expr=None, **kwargs) -> None:
+        if lookup_expr is None:
+            lookup_expr = 'iregex'
+        super().__init__(*args, lookup_expr=lookup_expr, **kwargs)
+
+    def filter(self, qs: FeedbackQuerySet, value: tuple[str, bool]) -> FeedbackQuerySet:
+        text_val, cb_val = value
+        if text_val:
+            if cb_val: # checkbox selected, use alternative search method
+                lookup = "%s__%s" % (self.field_name, self.lookup_expr)
+                return qs.filter(**{lookup: text_val})
+            # use our default method
+            return qs.filter_text(self.field_name, text_val)
+        return qs
+
+
 class ContainsTextFilter(django_filters.BooleanFilter):
     field_class = forms.BooleanField
 
@@ -241,15 +325,15 @@ class FeedbackFilter(django_filters.FilterSet):
     path_key = django_filters.CharFilter(
         lookup_expr='iregex',
         label=_("Exercise identifier"),
+        validators=[validate_regex],
         help_text=_(
             "Filter based on the exercise path key (typically of the "
             "format 'modulekey_chapterkey_exercisekey'). "
             "The filter uses case-insensitive regular expression match."
         )
     )
-    student_text = django_filters.CharFilter(
+    student_text = ComboTextSearchFilter(
         field_name='form_data',
-        method='filter_text',
         label=_("Student content"),
         help_text=_(
             "Filter conversations based on content of the student "
@@ -259,16 +343,25 @@ class FeedbackFilter(django_filters.FilterSet):
             "Otherwise the search is case-insensitive."
         ),
     )
-    teacher_text = django_filters.CharFilter(
+    student_text.field.widget.attrs.update({
+        'bool_label': _('Use regex search'),
+        'bool_helptext': _('Override default search method and use case-insensitive regex search instead.'),
+        'class': 'combosearch',
+    })
+    teacher_text = ComboTextSearchFilter(
         field_name='response_msg',
-        method='filter_text',
         label=_("Teacher content"),
         help_text=_(
             "Filter conversations based on text in the teacher responses. "
             "The operators 'AND', 'OR' and 'NOT' (case-sensitive) are supported. "
             "Otherwise the search is case-insensitive."
         ),
     )
+    teacher_text.field.widget.attrs.update({
+        'bool_label': _('Use regex search'),
+        'bool_helptext': _('Override default search method and use case-insensitive regex search instead.'),
+        'class': 'combosearch',
+    })
     contains_text = ContainsTextFilter(
         label=_("Display only feedback with text content"),
         help_text=_(
@@ -330,7 +423,3 @@ def form(self):
         form.fields['student_tags'].set_queryset(studenttags)
         form.fields['paginate_by'].initial = self.data.get('paginate_by', None)
         return form
-
-    @staticmethod
-    def filter_text(queryset, name, value):
-        return queryset.filter_text(name, value)

feedback/locale/fi/LC_MESSAGES/django.po

@@ -17,6 +17,10 @@ msgstr ""
 "Plural-Forms: nplurals=2; plural=(n != 1);\n"
 "X-Generator: Lokalize 2.0\n"
 
+#: feedback/filters.py
+msgid "Not a valid regex pattern"
+msgstr "Ei säännöllinen lauseke"
+
 #: feedback/filters.py
 msgid "Oldest first"
 msgstr "Vanhemmat ensin"
@@ -81,6 +85,17 @@ msgstr ""
 "'AND', 'OR' ja 'NOT' käyttöä. (Operaattorit ovat aakkoskoosta riippuvia, "
 "mutta muutoin haku on aakkoskoosta riippumaton.)"
 
+#: feedback/filters.py
+msgid "Use regex search"
+msgstr "Käytä regex-hakua"
+
+#: feedback/filters.py
+msgid ""
+"Override default search method and use case-insensitive regex search instead."
+msgstr
+"Etsi tavallisen hakumenetelmän sijaan säännöllisellä lausekkeella "
+"(case-insensitive regex)."
+
 #: feedback/filters.py
 msgid "Teacher content"
 msgstr "Opettajan vastaus"

feedback/static/feedback.css

@@ -14,6 +14,7 @@ body {
 	margin-top: 0.7em;
 	margin-bottom: 0.7em;
 	align-items: center;
+	display: flex;
 }
 .feedback-filter > label {
 	margin-bottom: 0;
@@ -27,9 +28,12 @@ body {
 .fb-filter-field {
 	display: inline;
 }
+.fb-filter-field.input-flex {
+	width: max(min(65%, 350px), 200px) !important;
+}
 .input-flex > div,
 .input-flex > input {
-	width: max(min(65%, 350px), 200px) !important;
+	width: max(100%, 200px) !important;
 }
 #filter-panel-bottom {
 	display: flex;
@@ -43,6 +47,19 @@ body {
 	float: right;
 }
 
+/* combo textsearch filter */
+label:has(~ .fb-filter-field > .combosearch) {
+	align-self: start;
+	margin-top: 0.5em;
+}
+input[type="checkbox"].combosearch {
+	margin-right: 0.3em;
+	margin-left: 0.3em;
+}
+input[type="checkbox"].combosearch + label {
+	margin-bottom: 0;
+}
+
 /* timestamp filter */
 #extra-filter-pane > div:first-child {
 	display: flex;
@@ -53,6 +70,30 @@ body {
 	width: calc(100% - min(30%, 150px) - 0.5em)
 }
 
+/* tag filters */
+.tag-filter-pane > .feedback-filter {
+	display: inline;
+}
+
+/* flag filters */
+.fb-filter-field:has(> #id_feedbackfilter_flags) {
+	width: 100%;
+}
+
+/* Displaying errors */
+.feedback-filter:has(> .errorlist) {
+	flex-wrap: wrap;
+	border: 1px #ebccd1;
+	background-color: #f2dede;
+	border-radius: 4px;
+}
+.feedback-filter > .errorlist {
+	width: 100%;
+	margin-bottom: 0;
+}
+
+/* responsive for different widths */
+
 @media (min-width: 750px) {
 	#filter-container {
 		display: grid;
@@ -133,10 +174,20 @@ body {
 }
 
 @media (max-width: 450px) {
+	.feedback-filter:has(> label.right-align),
+	.feedback-filter:has( #id_feedbackfilter_response_grade) {
+		flex-direction: column;
+	}
 	.feedback-filter label.right-align {
 		width: 100%;
 		text-align: left;
 	}
+	.feedback-filter:has( #id_feedbackfilter_response_grade) {
+		align-items: start;
+	}
+	.fb-filter-field.input-flex {
+		width: 100% !important;
+	}
 	.input-flex > div,
 	.input-flex > input {
 		width: 100% !important;

feedback/templates/feedback/widgets/combo_textsearch_widget.html

@@ -0,0 +1,18 @@
+{% spaceless %}
+{% for widget in widget.subwidgets %}
+	{% if not forloop.last %}
+		{% include widget.template_name %}
+	{% else %}
+		<div>
+			{% include widget.template_name %}
+			<label{% if widget.attrs.id %} for="{{ widget.attrs.id }}"{% endif %}
+				{% if widget.attrs.bool_helptext %}
+					data-toggle="tooltip" data-placement="right"
+					data-original-title="{{ widget.attrs.bool_helptext }}"
+				{% endif %}
+			>
+				{{ widget.attrs.bool_label }}
+			</label>
+		</div>
+	{% endif %}
+{% endfor %}{% endspaceless %}