CFWheels: Form Helper Radio Button - cfwheels

Question

I am using CFWheels for form validation. I have presenseOf() validation checks in both objects models. I have a form with a textbox and a set of radio buttons.
However If I submit the form empty, the validation for supervisor works but validation for the user checklist does not work. It gives the error;
"uchecklist" is not defined in the params variable.
On further observation, I notice that when the form is submitted, params struct has the "supervisor[name]" object but its empty, however it doesn't even have the "uchecklist[cstatus]" object. Moreover only when I select one of the radio buttons then the "uchecklist[cstatus]" object is submitted with that radio button's value.
I need to validate if at least one of the radio button is select, I guest this functionality is different from the empty text box validation.
Can someone show me how a radio button is validated using CFWheels form helpers.
Controller
public function t_validate()
{
title = "Home";
supervisor = model("supervisors");
uchecklist = model("user_checklist");
}
public function t_validate_complete()
{
title = "Home";
supervisor = model("supervisors").new(params.supervisor);
supervisor.save();
uchecklist = model("user_checklist").new(params.uchecklist);
uchecklist.save();
renderPage(action="t_validate");
}
View
<cfoutput>
<cfdump var="#params#">
#errorMessagesFor("supervisor")#
#startFormTag(action="t_validate_complete")#
<div>
<label for="">Supervisor:</label>
<input name="supervisor[name]" value="" />
</div>
<fieldset>
<input type="radio" name="uchecklist[cstatus]" value="1" />
<label for="profile-eyeColorId-2">Blue</label><br />
<input type="radio" name="uchecklist[cstatus]" value="2" />
<label for="profile-eyeColorId-1">Brown</label><br />
<input type="radio" name="uchecklist[cstatus]" value="3" />
<label for="profile-eyeColorId-3">Hazel</label><br />
</fieldset>
<div>
<input type="submit" value="Save Changes" />
</div>
#endFormTag()#
</cfoutput>

Answer 1

An unchecked radio button will submit no data to the server. This isn't a unique problem to ColdFusion or CFWheels.
To fix, provide a default value for the struct at the beginning of your controller action:
public function t_validate_complete()
{
// Provides an empty struct for the model to consume if none of the radio buttons are checked.
param name="params.uchecklist" type="struct" default="#StructNew()#";
title = "Home";
supervisor = model("supervisors").new(params.supervisor);
supervisor.save();
uchecklist = model("user_checklist").new(params.uchecklist);
uchecklist.save();
renderPage(action="t_validate");
}