Make Build object into a MPTT tree model

- Builds can have child builds

InvenTree/build/migrations/0013_auto_20200425_0507.py

@@ -0,0 +1,55 @@
+# Generated by Django 3.0.5 on 2020-04-25 05:07
+
+from django.db import migrations, models
+import django.db.models.deletion
+import mptt.fields
+from build.models import Build
+
+
+def update_tree(apps, schema_editor):
+    # Update the Build MPTT model
+    Build.objects.rebuild()
+
+
+def nupdate_tree(apps, schema_editor):
+    pass
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('build', '0012_build_sales_order'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='build',
+            name='level',
+            field=models.PositiveIntegerField(default=0, editable=False),
+            preserve_default=False,
+        ),
+        migrations.AddField(
+            model_name='build',
+            name='lft',
+            field=models.PositiveIntegerField(default=0, editable=False),
+            preserve_default=False,
+        ),
+        migrations.AddField(
+            model_name='build',
+            name='parent',
+            field=mptt.fields.TreeForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.DO_NOTHING, related_name='children', to='build.Build'),
+        ),
+        migrations.AddField(
+            model_name='build',
+            name='rght',
+            field=models.PositiveIntegerField(default=0, editable=False),
+            preserve_default=False,
+        ),
+        migrations.AddField(
+            model_name='build',
+            name='tree_id',
+            field=models.PositiveIntegerField(db_index=True, default=0, editable=False),
+            preserve_default=False,
+        ),
+        migrations.RunPython(update_tree, reverse_code=nupdate_tree),
+    ]

InvenTree/build/models.py

@@ -18,6 +18,8 @@ from django.core.validators import MinValueValidator
 
 from markdownx.models import MarkdownxField
 
+from mptt.models import MPTTModel, TreeForeignKey
+
 from InvenTree.status_codes import BuildStatus
 from InvenTree.fields import InvenTreeURLField
 from InvenTree.helpers import decimal2string
@@ -26,13 +28,14 @@ from stock.models import StockItem
 from part.models import Part, BomItem
 
 
-class Build(models.Model):
+class Build(MPTTModel):
     """ A Build object organises the creation of new parts from the component parts.
 
     Attributes:
         part: The part to be built (from component BOM items)
         title: Brief title describing the build (required)
         quantity: Number of units to be built
+        parent: Reference to a Build object for which this Build is required
         sales_order: References to a SalesOrder object for which this Build is required (e.g. the output of this build will be used to fulfil a sales order)
         take_from: Location to take stock from to make this build (if blank, can take from anywhere)
         status: Build status code
@@ -44,7 +47,7 @@ class Build(models.Model):
     """
 
     def __str__(self):
-        return "Build {q} x {part}".format(q=decimal2string(self.quantity), part=str(self.part))
+        return "{q} x {part}".format(q=decimal2string(self.quantity), part=str(self.part.full_name))
 
     def get_absolute_url(self):
         return reverse('build-detail', kwargs={'pk': self.id})
@@ -55,6 +58,13 @@ class Build(models.Model):
         help_text=_('Brief description of the build')
     )
 
+    parent = TreeForeignKey(
+        'self',
+        on_delete=models.DO_NOTHING,
+        blank=True, null=True,
+        related_name='children'
+    )
+
     part = models.ForeignKey(
         'part.Part',
         on_delete=models.CASCADE,

InvenTree/build/templates/build/build_base.html

@@ -75,6 +75,13 @@ src="{% static 'img/blank_image.png' %}"
         <td>{% trans "Status" %}</td>
         <td>{% build_status_label build.status %}</td>
     </tr>
+    {% if build.parent %}
+    <tr>
+        <td><span class='fas fa-tools'></span></td>
+        <td>{% trans "Parent Build" %}</td>
+        <td><a href="{% url 'build-detail' build.parent.id %}">{{ build.parent }}</a></td>
+    </tr>
+    {% endif %}
     {% if build.sales_order %}
     <tr>
         <td><span class='fas fa-dolly'></span></td>