class CacheControl

PRIVATE = "private"

The private directive indicates that the response is intended for a single user and must not be stored by shared caches.

PUBLIC = "public"

The public directive indicates that the response may be stored by any cache, even if it would normally be considered non-cacheable.

NO_CACHE = "no-cache"

The no-cache directive indicates that caches must revalidate the response with the origin server before serving it to clients.

NO_STORE = "no-store"

The no-store directive indicates that caches must not store the response under any circumstances.

MAX_AGE = "max-age"

The max-age directive indicates the maximum amount of time, in seconds, that a response is considered fresh.

S_MAXAGE = "s-maxage"

The s-maxage directive is similar to max-age but applies only to shared caches. If both s-maxage and max-age are present, s-maxage takes precedence in shared caches.

STATIC = "static"

The static directive is a custom directive often used to indicate that the resource is immutable or rarely changes, allowing longer caching periods.

DYNAMIC = "dynamic"

The dynamic directive is a custom directive used to indicate that the resource is generated dynamically and may change frequently, requiring shorter caching periods.

STREAMING = "streaming"

The streaming directive is a custom directive used to indicate that the resource is intended for progressive or chunked delivery, such as live video streams.

MUST_REVALIDATE = "must-revalidate"

The must-revalidate directive indicates that once a response becomes stale, caches must not use it to satisfy subsequent requests without revalidating it with the origin server.

PROXY_REVALIDATE = "proxy-revalidate"

The proxy-revalidate directive is similar to must-revalidate but applies only to shared caches.

def initialize(value = nil)

Initializes the cache control header with the given value. The value is expected to be a comma-separated string of cache directives.

def initialize(value = nil)
	super(value&.downcase)
end

def <<(value)

Adds a directive to the Cache-Control header. The value will be normalized to lowercase before being added.

def << value
	super(value.downcase)
end

def static?

def static?
	self.include?(STATIC)
end

def dynamic?

def dynamic?
	self.include?(DYNAMIC)
end

def streaming?

def streaming?
	self.include?(STREAMING)
end

def private?

def private?
	self.include?(PRIVATE)
end

def public?

def public?
	self.include?(PUBLIC)
end

def no_cache?

def no_cache?
	self.include?(NO_CACHE)
end

def no_store?

def no_store?
	self.include?(NO_STORE)
end

def must_revalidate?

def must_revalidate?
	self.include?(MUST_REVALIDATE)
end

def proxy_revalidate?

def proxy_revalidate?
	self.include?(PROXY_REVALIDATE)
end

def max_age

def max_age
	find_integer_value(MAX_AGE)
end

def s_maxage

def s_maxage
	find_integer_value(S_MAXAGE)
end

def find_integer_value(value_name)

Finds and parses an integer value from a directive.

def find_integer_value(value_name)
	if value = self.find{|value| value.start_with?(value_name)}
		_, age = value.split("=", 2)
		
		if age =~ /\A[0-9]+\z/
			return Integer(age)
		end
	end
end