Fixes #4598: Display error message when invalid cable length is specified

docs/release-notes/version-2.8.md

@@ -1,5 +1,13 @@
 # NetBox v2.8
 
+v2.8.4 (FUTURE)
+
+### Bug Fixes
+
+* [#4598](https://github.com/netbox-community/netbox/issues/4598) - Display error message when invalid cable length is specified
+
+---
+
 ## v2.8.3 (2020-05-06)
 
 ### Bug Fixes

netbox/dcim/forms.py

@@ -3659,6 +3659,11 @@ class CableForm(BootstrapMixin, forms.ModelForm):
             'type': StaticSelect2,
             'length_unit': StaticSelect2,
         }
+        error_messages = {
+            'length': {
+                'max_value': 'Maximum length is 32767 (any unit)'
+            }
+        }
 
 
 class CableCSVForm(CSVModelForm):

netbox/templates/dcim/inc/cable_form.html

@@ -10,9 +10,23 @@
             <label class="col-md-3 control-label" for="id_length">{{ form.length.label }}</label>
             <div class="col-md-5">
                 {{ form.length }}
+                {% if form.length.errors %}
+                    <ul>
+                        {% for error in form.length.errors %}
+                            <li class="text-danger">{{ error }}</li>
+                        {% endfor %}
+                    </ul>
+                {% endif %}
             </div>
             <div class="col-md-4">
                 {{ form.length_unit }}
+                {% if form.length_unit.errors %}
+                    <ul>
+                        {% for error in form.length_unit.errors %}
+                            <li class="text-danger">{{ error }}</li>
+                        {% endfor %}
+                    </ul>
+                {% endif %}
             </div>
         </div>
     </div>