Rack reservations (#900)

* Initial work on rack reservations

* Added views for rack reservations

* Implemented ArrayFieldSelectMultiple form widget

* Implemented API endpoints for rack reservations

* Tweaked the database migration

netbox/utilities/forms.py

@@ -169,6 +169,27 @@ class SelectWithDisabled(forms.Select):
                            force_text(option_label))
 
 
+class ArrayFieldSelectMultiple(SelectWithDisabled, forms.SelectMultiple):
+    """
+    MultiSelect widgets for a SimpleArrayField. Choices must be populated on the widget.
+    """
+
+    def __init__(self, *args, **kwargs):
+        self.delimiter = kwargs.pop('delimiter', ',')
+        super(ArrayFieldSelectMultiple, self).__init__(*args, **kwargs)
+
+    def render_options(self, selected_choices):
+        # Split the delimited string of values into a list
+        if selected_choices:
+            selected_choices = selected_choices.split(self.delimiter)
+        return super(ArrayFieldSelectMultiple, self).render_options(selected_choices)
+
+    def value_from_datadict(self, data, files, name):
+        # Condense the list of selected choices into a delimited string
+        data = super(ArrayFieldSelectMultiple, self).value_from_datadict(data, files, name)
+        return self.delimiter.join(data)
+
+
 class APISelect(SelectWithDisabled):
     """
     A select widget populated via an API call

netbox/utilities/templatetags/helpers.py

@@ -27,6 +27,14 @@ def getlist(value, arg):
     return value.getlist(arg)
 
 
+@register.filter
+def getkey(value, key):
+    """
+    Return a dictionary item specified by key
+    """
+    return value[key]
+
+
 @register.filter(is_safe=True)
 def gfm(value):
     """