Update TO route helper function to catch error and display flash message when a user tries to save a TO with an existing number.

Update TaskOrderForm so that it converts empty string for number into None, this was causing an issue where new TOs were being saved with an empty string for the number, which violated the unique constraint.

atst/routes/task_orders/new.py

@@ -10,7 +10,7 @@ from flask import (
 
 from .blueprint import task_orders_bp
 from atst.domain.authz.decorator import user_can_access_decorator as user_can
-from atst.domain.exceptions import NoAccessError
+from atst.domain.exceptions import NoAccessError, AlreadyExistsError
 from atst.domain.task_orders import TaskOrders
 from atst.forms.task_order import TaskOrderForm, SignatureForm
 from atst.models.permissions import Permissions
@@ -50,7 +50,26 @@ def render_task_orders_edit(
     return render_template(template, **render_args)
 
 
-def update_task_order(
+def update_task_order(form, portfolio_id=None, task_order_id=None, flash_invalid=True):
+    if form.validate(flash_invalid=flash_invalid):
+        task_order = None
+        try:
+            if task_order_id:
+                task_order = TaskOrders.update(task_order_id, **form.data)
+                portfolio_id = task_order.portfolio_id
+            else:
+                task_order = TaskOrders.create(portfolio_id, **form.data)
+
+            return task_order
+
+        except AlreadyExistsError:
+            flash("task_order_number_error", to_number=form.data["number"])
+            return False
+    else:
+        return False
+
+
+def update_and_render_next(
     form_data, next_page, current_template, portfolio_id=None, task_order_id=None
 ):
     form = None
@@ -60,14 +79,8 @@ def update_task_order(
     else:
         form = TaskOrderForm(form_data)
 
-    if form.validate():
-        task_order = None
-        if task_order_id:
-            task_order = TaskOrders.update(task_order_id, **form.data)
-            portfolio_id = task_order.portfolio_id
-        else:
-            task_order = TaskOrders.create(portfolio_id, **form.data)
-
+    task_order = update_task_order(form, portfolio_id, task_order_id)
+    if task_order:
         return redirect(url_for(next_page, task_order_id=task_order.id))
     else:
         return (
@@ -149,7 +162,7 @@ def submit_form_step_one_add_pdf(portfolio_id=None, task_order_id=None):
     next_page = "task_orders.form_step_two_add_number"
     current_template = "task_orders/step_1.html"
 
-    return update_task_order(
+    return update_and_render_next(
         form_data,
         next_page,
         current_template,
@@ -176,12 +189,8 @@ def cancel_edit(task_order_id=None, portfolio_id=None):
         else:
             form = TaskOrderForm(form_data)
 
-        if form.validate(flash_invalid=False):
-            task_order = None
-            if task_order_id:
-                task_order = TaskOrders.update(task_order_id, **form.data)
-            else:
-                task_order = TaskOrders.create(portfolio_id, **form.data)
+        update_task_order(form, portfolio_id, task_order_id, flash_invalid=False)
+
     elif not save and task_order_id:
         TaskOrders.delete(task_order_id)
 
@@ -205,7 +214,7 @@ def submit_form_step_two_add_number(task_order_id):
     next_page = "task_orders.form_step_three_add_clins"
     current_template = "task_orders/step_2.html"
 
-    return update_task_order(
+    return update_and_render_next(
         form_data, next_page, current_template, task_order_id=task_order_id
     )
 
@@ -225,7 +234,7 @@ def submit_form_step_three_add_clins(task_order_id):
     next_page = "task_orders.form_step_four_review"
     current_template = "task_orders/step_3.html"
 
-    return update_task_order(
+    return update_and_render_next(
         form_data, next_page, current_template, task_order_id=task_order_id
     )