What is `params.require(:person).permit(:name, :age)` doing in Rails 4?

Question

All the examples of strong parameters in Rails 4 docs use

params.require(:person).permit(:name, :age)

Could someone please deconstruct and

Answer 1

To be more precise, when you create for eg. doing .new(...), there must be :person hash indicated by require and the person hash will only accept :name and :age indicated by permit.

Example:

.new(person: { name: "Bhojendra", age: 32 }) // okay
.new(person: { name: "Rauniyar" }) // okay
.new(person: { name: "Bhojendra", other: 'asdf' }) // not okay, other not permitted
.new(person: { full_name: "Bhojendra Rauniyar" }) // not okay, full_name not permitted
.new(detail: { name: "Bhojendra", age: 32 }) // not okay, must be person