undefined method `include?' for nil:NilClass with partial validation of wizard gem

Question

I am trying to follow the guide for partial validation on object using the wizard gem, but I keep getting the error undefined method `include?' for nil:NilClass, cant understand what is wrong, have tried to follow the step by step instructions. The error in the log shows. ``` NoMethodError - undefined method `include?' for nil:NilClass: app/models/property.rb:22:in `active_or_tenants?' ``` Here is my steps controller. ``` class Properties::BuildController < ApplicationController include Wicked::Wizard steps :tenant, :confirmed def show @property = Property.find(params[:property_id]) @tenants = @property.tenants.new(params[:tenant_id]) render_wizard end def update @property = Property.find(params[:property_id]) params[:property][:status] = step.to_s params[:property][:status] = 'active' if step == steps.last @property.update_attributes(params[:property]) render_wizard @property end def create @property = current_user.properties.build(params[:property]) logger.info @property.attributes…

Accepted Answer

From my comments:

The `status` is an attribute of your Property model. It can be `nil` which raises an error in certain cases:

```
undefined method include?' for nil:NilClass
```

It is actually trying to compare `nil` to `'tenants'` (String).

To fix that, you can use an empty string to be compared if `status` is `nil`,

```
# an example (you can try in your IRB console):
nil || "No value"
# => returns "No value"
```

in your case:

```
def active_or_tenants?
  status.to_s.include?('tenants') || active?
end
```

`nil.to_s` return an empty string. Which solves your problem ;)

Actually, the methods `to_s`, `to_i`, `to_f` etc. are often used to remove the possible `nil`:

```
# in ruby console:
2.3.3 :018 > nil.to_i
# => 0 
2.3.3 :019 > nil.to_f
# => 0.0 
2.3.3 :020 > nil.to_s
# => "" 
2.3.3 :021 > nil.to_a
# => [] 
```

undefined method `include?' for nil:NilClass with partial validation of wizard gem

Solution

Problem