donate: Fix targeted donations form

donate/forms.py

@@ -22,6 +22,15 @@ class DonateForm(forms.Form):
             raise forms.ValidationError("Wrong periodicity!")
         return value
 
+    def clean(self):
+        cleaned_data = super().clean()
+        if (
+            cleaned_data["portal_project_id"] == self.PORTAL_ID_IN_SELECT
+            and cleaned_data["select_portal_project_id"] is None
+        ):
+            raise forms.ValidationError("Není zadán účel daru.")
+        return cleaned_data
+
     def get_amount(self):
         amount = self.cleaned_data["amount"]
         if amount == self.CUSTOM_AMOUNT:

donate/static/donate/assets/js/scripts.js

@@ -92,7 +92,7 @@
   });
 
   $("#other_target_select").change(function () {
-    if ($(this).val() !== "-") {
+    if ($(this).val() !== "") {
       $("#other_target").prop("checked", true);
       updateLink($(this).val());
     }

donate/templates/donate/donate_targeted_donations_page.html

@@ -37,7 +37,7 @@
                   <label class="custom-control-label col-form-label-lg custom-control-label-for-select" for="other_target">
                     Dar pro:
                     <select id="other_target_select" name="select_portal_project_id" class="custom-control-select">
-                      <option value="-">--- vybrat ---</option>
+                      <option value="">--- vybrat ---</option>
                       {% for target in other_targets %}
                         <option value="{{ target.portal_project_id }}">{{ target.title }}</option>
                       {% endfor %}