Adds function to duplicate a BOM from a parent part

- Improves form validation workflow
- More 'djangoesque'

InvenTree/part/templates/part/bom.html

@@ -39,8 +39,13 @@
             <span class='fas fa-trash-alt'></span>
         </button>
         <button class='btn btn-primary' type='button' title='{% trans "Import BOM data" %}' id='bom-upload'>
-            <span class='fas fa-file-upload'></span> {% trans "Upload" %}
+            <span class='fas fa-file-upload'></span> {% trans "Import from File" %}
         </button>
+        {% if part.variant_of %}
+        <button class='btn btn-default' type='button' title='{% trans "Copy BOM from parent part" %}' id='bom-duplicate'>
+            <span class='fas fa-clone'></span> {% trans "Copy from Parent" %}
+        </button>
+        {% endif %}
         <button class='btn btn-default' type='button' title='{% trans "New BOM Item" %}' id='bom-item-new'>
             <span class='fas fa-plus-circle'></span> {% trans "Add Item" %}
         </button>
@@ -157,6 +162,17 @@
         location.href = "{% url 'upload-bom' part.id %}";
     });
 
+    $('#bom-duplicate').click(function() {
+        launchModalForm(
+            "{% url 'duplicate-bom' part.id %}",
+            {
+                success: function() {
+                    $('#bom-table').bootstrapTable('refresh');
+                }
+            }
+        );
+    });
+
     $("#bom-item-new").click(function () {
         launchModalForm(
             "{% url 'bom-item-create' %}?parent={{ part.id }}",

InvenTree/part/templates/part/bom_duplicate.html

@@ -0,0 +1,17 @@
+{% extends "modal_form.html" %}
+{% load i18n %}
+
+{% block pre_form_content %}
+
+<p>
+    {% trans "Select parent part to copy BOM from" %}
+</p>
+
+{% if part.has_bom %}
+<div class='alert alert-block alert-danger'>
+    <b>{% trans "Warning" %}</b><br>
+    {% trans "This part already has a Bill of Materials" %}<br>
+</div>
+{% endif %}
+
+{% endblock %}