Basic frontend uploader component

atst/forms/task_order.py

@@ -1,6 +1,7 @@
-from wtforms.fields import BooleanField, DecimalField, StringField
+from wtforms.fields import BooleanField, DecimalField, FileField, StringField
 from wtforms.fields.html5 import DateField
 from wtforms.validators import Required, Optional
+from flask_wtf.file import FileAllowed
 
 from .forms import BaseForm
 from atst.utils.localization import translate
@@ -12,6 +13,13 @@ class TaskOrderForm(BaseForm):
         description=translate("forms.task_order.number_description"),
         validators=[Required()],
     )
+    pdf = FileField(
+        None,
+        validators=[
+            FileAllowed(["pdf"], translate("forms.task_order.file_format_not_allowed"))
+        ],
+        render_kw={"accept": ".pdf,application/pdf"},
+    )
 
 
 class FundingForm(BaseForm):