Added Part Templates

InvenTree/part/models.py

@@ -2,7 +2,7 @@ from __future__ import unicode_literals
 
 from django.db import models
 from django.db.models import Sum
-from django.core.exceptions import ObjectDoesNotExist
+from django.core.exceptions import ObjectDoesNotExist, ValidationError
 
 from InvenTree.models import InvenTreeTree
 
@@ -75,7 +75,67 @@ class Part(models.Model):
                 projects.append(pp.project)
                 
         return projects
+    
+class PartParameterTemplate(models.Model):
+    """ A PartParameterTemplate pre-defines a parameter field,
+    ready to be copied for use with a given Part.
+    A PartParameterTemplate can be optionally associated with a PartCategory
+    """
+    
+    category = models.ForeignKey(PartCategory, on_delete=models.CASCADE, blank=True, null=True)
+    
+    name = models.CharField(max_length=20)
+    description = models.CharField(max_length=100, blank=True)
+    units = models.CharField(max_length=10, blank=True)
+    
+    default_value = models.CharField(max_length=50, blank=True)
+    default_min = models.CharField(max_length=50, blank=True)
+    default_max = models.CharField(max_length=50, blank=True)
+    
+    def __str__(self):
+        return "{name} ({units})".format(
+            name=self.name,
+            units=self.units)
+    
+    class Meta:
+        verbose_name = "Parameter Template"
+        verbose_name_plural = "Parameter Templates"
+    
 
+class PartParameter(models.Model):
+    """ PartParameter is associated with a single part
+    """
+    
+    part = models.ForeignKey(Part, on_delete=models.CASCADE)
+    
+    template = models.ForeignKey(PartParameterTemplate)
+    
+    # Value data
+    value = models.CharField(max_length=50, blank=True)
+    min_value = models.CharField(max_length=50, blank=True)
+    max_value = models.CharField(max_length=50, blank=True)
+    
+    # Prevent multiple parameters of the same template
+    # from being added to the same part
+    def save(self, *args, **kwargs):
+        params = PartParameter.objects.filter(part=self.part, template=self.template)
+        if len(params) > 0:
+            raise ValidationError("Parameter '{param}' already exists for {part}".format(
+                param=self.template.name,
+                part=self.part.name))
+            
+        super(PartParameter, self).save(*args, **kwargs)
+    
+    def __str__(self):
+        return "{name} : {val}{units}".format(
+            name=self.template.name,
+            val=self.value,
+            units=self.template.units)
+            
+    class Meta:
+        verbose_name = "Part Parameter"
+        verbose_name_plural = "Part Parameters"
+    
 
 class PartRevision(models.Model):
     """ A PartRevision represents a change-notification to a Part