How would you tidy up this controller logic? - ruby-on-rails

Question

I've got some logic in a controller that sets a status of an object if certain conditions are met:
if params[:concept][:consulted_legal] == 0 && params[:concept][:consulted_marketing] == 1
#concept.attributes = {:status => 'Awaiting Compliance Approval'}
elsif params[:concept][:consulted_marketing] == 0 && params[:concept][:consulted_legal] == 1
#concept.attributes = {:status => 'Awaiting Marketing Approval'}
elsif params[:concept][:consulted_marketing] == 0 && params[:concept][:consulted_legal] == 0
#concept.attributes = {:status => 'Awaiting Marketing & Legal Approval'}
else
#concept.attributes = {:status => 'Pending Approval'}
end
that I share between create and update actions. How would you go about refactoring this nastiness? Looking for best practices.
New to programming and keen to clean up my code.
TIA.

Answer 1

You can make your code less dependent on both conditions and make it a lot more flexible.
waiting_on = []
waiting_on << 'Compliance' unless params[:concept][:consulted_marketing]
waiting_on << 'Legal' unless params[:concept][:consulted_legal]
status = waiting_on.empty? ? "Awaiting #{waiting_on.join(' & ')} Approval" : 'Pending Approval'
#concept.attributes = {:status => status}
Version for both create and update without filter:
def create
set_concept_status_attribute
...
end
def update
set_concept_status_attribute
...
end
private
def set_concept_status_attribute
waiting_on = []
waiting_on << 'Compliance' unless params[:concept][:consulted_marketing]
waiting_on << 'Legal' unless params[:concept][:consulted_legal]
status = waiting_on.empty? ? "Awaiting #{waiting_on.join(' & ')} Approval" : 'Pending Approval'
#concept.attributes = {:status => status}
end
Or with a before_filter:
before_filter :set_concept_status_attribute, :only => [:create, :update]
def create
...
end
def update
...
end
If you can move it to you view, it looks even better:
module ConceptHelper
def get_concept_status
...
end
end
<%= get_concept_status %>

Answer 2

This is my take on it. I call it Super DRY.
statuses =
[
['Awaiting Marketing & Legal Approval','Awaiting Compliance Approval'],
['Awaiting Marketing Approval','Pending Approval']
]
{:status => statuses[params[:concept][:consulted_legal].to_i][params[:concept][:consulted_marketing].to_i]}
Alternatively, a more conventional approach -- lengthy but readable:
status = if params[:concept][:consulted_legal] == "0"
if params[:concept][:consulted_marketing] == "1"
'Awaiting Compliance Approval'
else
'Awaiting Marketing & Legal Approval'
end
else
if params[:concept][:consulted_marketing] == "0"
'Awaiting Marketing Approval'
else
'Pending Approval'
end
end
#concept.attributes = {:status => status}
Note: It looks like your original code is checking values of check boxes. Values in the params hash are always Strings, not Fixnums so my code compares strings. If for some reason comparing Fixnums is what is required for your situation, just take out the quotes around the numbers.

Answer 3

That looks to be business logic, so it should be in the model really.
Your model probably needs a couple of attributes: consulted_legal and consulted_marketing, and a method to set the status when either one of them is changed something like this:
before_update :set_status
def set_status
if consulted_legal && consulted_marketing
status = "Pending Approval"
elif consulted_legal && !consulted_marketing
status = "Awaiting Marketing Approval"
elif !consulted_legal && consulted_marketing
status = "Awaiting Legal Approval"
elif !consulted_legal && !consulted_marketing
status "Awaiting Marketing & Legal Approval"
end
true # Needs to return true for the update to go through
end

Answer 4

Break it down into nested if statements.
if params[:concept][:consulted_legal] == '0'
if params[:concept][:consulted_marketing] == '1'
#concept.attributes = { :status => 'Awaiting Compliance Approval' }
else
#concept.attributes = { :status => 'Awaiting Marketing & Legal Approval' }
end
else
if params[:consulted_marketing] == '1'
#concept.attributes = { :status => 'Awaiting Marketing Approval' }
else
#concept.attributes = { :status => "Pending Approval" }
end
end

Answer 5

you may think the list of departments consulted is a fixed enough concept to justify variables named consulted_marketing etc.. But for growth, and dryness (in a way), Id prefer a list of departments.
What you really have here is a workflow or state machine, I think a list of deparments with transitions would result in the cleanest, most growable code.
Code is data ! Model your data and the code will be trivial.

Answer 6

This looks like a business rule to me. As such you might want to wrap it into a function:
string GetConceptStatus(bool consulted_legal, bool consulted_marketing)
{
if (consulted_legal && consulted_marketing) {
return "Pending Approval";
}
if (consulted_legal && !consulted_marketing) {
return "Awaiting Marketing Approval";
}
if (!consulted_legal && consulted_marketing) {
return "Awaiting Legal Approval";
}
if (!consulted_legal && !consulted_marketing) {
return "Awaiting Marketing & Legal Approval";
}
}
This also separates the details of how bools are encoded in your interface from the actual implementation of the business rule.
But the actual structure of the code looks good to me, since it probably better models the business rule.