Added form validation

* Asset IDs must be unique
* Asset IDs that are legacy and unchange have no validation applied
* Asset IDs must be alphanumeric
* Values must be >=0
* Lengths, CSAs, Circuits and Cores of cables must all be >0

assets/forms.py

@@ -1,16 +1,12 @@
 from django import forms
 from django.core.exceptions import ValidationError
+import re
 
 from assets import models
 
 
 class AssetForm(forms.ModelForm):
     
-
-    def clean_date_sold(self):
-        if self.cleaned_data["date_sold"] and self.cleaned_data["date_acquired"] > self.cleaned_data["date_sold"]:
-            raise ValidationError("Cannot sell an item before it is acquired")
-        return self.cleaned_data["date_sold"]
     
     class Meta:
         model = models.Asset
@@ -19,10 +15,61 @@ class AssetForm(forms.ModelForm):
             'is_cable' : forms.CheckboxInput()
         }
 
+    def clean_date_sold(self):
+        if self.cleaned_data["date_sold"] and self.cleaned_data["date_acquired"] > self.cleaned_data["date_sold"]:
+            raise ValidationError("Cannot sell an item before it is acquired")
+        return self.cleaned_data["date_sold"]
+    
+    def clean_asset_id(self):
+        # If the asset ID has been changed
+        if self.instance.asset_id and self.instance.asset_id == self.cleaned_data["asset_id"]: #If the item was not changed
+            return self.cleaned_data["asset_id"]
+        else:
+            if re.search("^[a-zA-Z0-9]+$", self.cleaned_data["asset_id"]) == None:
+                raise ValidationError("An Asset ID can only consist of letters and numbers")
+            return self.cleaned_data["asset_id"]
+
+    def clean_purchase_price(self):
+        purchase_price = self.cleaned_data["purchase_price"]
+        if purchase_price and purchase_price < 0:
+            raise ValidationError("A price cannot be negative")
+        return purchase_price
+
+    def clean_salvage_value(self):
+        salvage_value = self.cleaned_data["salvage_value"]
+        if salvage_value and salvage_value < 0:
+            raise ValidationError("A price cannot be negative")
+        return salvage_value
+
+
 class CableForm(AssetForm):
     class Meta(AssetForm.Meta):
         model = models.Cable
 
+    def clean_length(self):
+        length = self.cleaned_data["length"]
+        if length <= 0:
+            raise ValidationError("The length of a cable must be more than 0")
+        return length
+
+    def clean_csa(self):
+        csa = self.cleaned_data["csa"]
+        if csa <= 0:
+            raise ValidationError("The CSA of a cable must be more than 0")
+        return csa
+
+    def clean_circuits(self):
+        circuits = self.cleaned_data["circuits"]
+        if circuits <= 0:
+            raise ValidationError("There must be at least one circuit")
+        return circuits
+    
+    def clean_cores(self):
+        cores = self.cleaned_data["cores"]
+        if cores <= 0:
+            raise ValidationError("There must be at least one core")
+        return cores
+
 class SupplierForm(forms.Form):
     class Meta:
         model = models.Supplier