add uuid check

app/views/exercises/_export_actions.html.slim

@@ -0,0 +1,20 @@
+- if error
+    = button_tag type: 'button', class:'btn btn-primary pull-right export-button', onclick: "exportExerciseStart(#{exercise.id})" do
+      i.fa.fa-refresh.confirm-icon
+      = ' Retry'
+- else
+  - if exercise_found
+    - if update_right
+      = button_tag type: 'button', class:'btn btn-primary pull-right export-action export-button', data: {'export-type' => 'export'} do
+        i.fa.fa-check.confirm-icon
+        = ' Overwrite'
+    = button_tag type: 'button', class:'btn btn-primary pull-right export-action export-button', data: {'export-type' => 'create_new'} do
+      i.fa.fa-check.confirm-icon-alt
+      = ' Create new'
+  - else
+    = button_tag type: 'button', class:'btn btn-primary pull-right export-action export-button', data: {'export-type' => 'export'} do
+      i.fa.fa-check.confirm-icon
+      = ' Export'
+= button_tag type: 'submit', class:'btn btn-secondary pull-right export-button', data: {dismiss: 'modal'} do
+  i.fa.fa-remove.abort-icon
+  = ' Abort'

app/views/exercises/_export_dialogcontent.html.slim

@@ -0,0 +1,5 @@
+#export-exercise
+  .export-message
+    = 'This should not be seen'
+  .export-exercise-actions
+    = 'This neither'

app/views/exercises/index.html.slim

@@ -46,7 +46,9 @@ h1 = Exercise.model_name.human(count: 2)
                 li = link_to(t('activerecord.models.user_exercise_feedback.other'), feedback_exercise_path(exercise), class: 'dropdown-item') if policy(exercise).feedback?
                 li = link_to(t('shared.destroy'), exercise, data: {confirm: t('shared.confirm_destroy')}, method: :delete, class: 'dropdown-item') if policy(exercise).destroy?
                 li = link_to(t('.clone'), clone_exercise_path(exercise), data: {confirm: t('shared.confirm_destroy')}, method: :post, class: 'dropdown-item') if policy(exercise).clone?
-                li = link_to(t('exercises.export_codeharbor.label'), push_proforma_xml_exercise_path(exercise), method: :post, class: 'dropdown-item') if policy(exercise).push_proforma_xml?
+                li = link_to(t('exercises.export_codeharbor.label'), '', class: 'dropdown-item export-start', data: {'exercise-id' => exercise.id}) if policy(exercise).push_proforma_xml?
 
 = render('shared/pagination', collection: @exercises)
 p = render('shared/new_button', model: Exercise)
+
+= render('shared/modal', id: 'export-modal', title: t('exercises.export_codeharbor.dialogtitle'), template: 'exercises/_export_dialogcontent')