Cookies are accessible through the Request instance of Context. The ctx.Request() returns a net/http#Request.

However the Iris Context provides some helpers to make the most common use cases of cookies easier accessible to you and without any custom additional code of yours that would be required if you just using the Request's Cookies methods.

Set a Cookie

The SetCookie and UpsertCookie methods add or set (replaces if necessary) a cookie.

The last argument of "options" is optional. a CookieOption can be used to modify the "cookie". You'll see later on what the available options are, custom ones can be added depending on your web application requirements, this also helps to not repeat yourself in a codebase.

Before we continue, the Context has a SetSameSite(http.SameSite) method too. It sets the "SameSite" cookie field for all cookies to be sent.

SetCookie(cookie *http.Cookie, options ...CookieOption)

If you want you can also use the SetCookieKV method which does not require an import of the net/http package.

SetCookieKV(name, value string, options ...CookieOption)

Note that the default expiration for a cookie set by SetCookieKV is 365 days. You can either use the CookieExpires Cookie Option(see below) or globally by setting the kataras/iris/Context.SetCookieKVExpiration package-level variable.

The CookieOption is just a type for func(*http.Cookie).

Set Path

CookiePath(path string) CookieOption

Set Expiration

iris.CookieExpires(durFromNow time.Duration) CookieOption

HttpOnly

iris.CookieHTTPOnly(httpOnly bool) CookieOption

HttpOnly field defaults to true for RemoveCookie and SetCookieKV.

And let's go a bit further with cookie encoding.

Encode

Provides encoding functionality when adding a cookie.

Accepts a CookieEncoder and sets the cookie's value to the encoded value.

Users of that is the SetCookie and SetCookieKV.

iris.CookieEncode(encode CookieEncoder) CookieOption

Decode

Provides decoding functionality when retrieving a cookie.

Accepts a CookieDecoder and sets the cookie's value to the decoded value before return by the GetCookie.

User of that is the GetCookie.

iris.CookieDecode(decode CookieDecoder) CookieOption

Where CookieEncoder can be described as:

A CookieEncoder should encode the cookie value.

• Should accept the cookie's name as its first argument and

• as second argument the cookie value ptr.

• Should return an encoded value or an empty one if encode operation failed.

• Should return an error if encode operation failed.

CookieEncoder func(cookieName string, value interface{}) (string, error)

And CookieDecoder:

CookieDecoder should decode the cookie value.

• Should accept the cookie's name as its first argument,

• as second argument the encoded cookie value and as third argument the decoded value ptr.

• Should return a decoded value or an empty one if decode operation failed.

• Should return an error if decode operation failed.

CookieDecoder func(cookieName string, cookieValue string, v interface{}) error

Errors are not printed, so you have to know what you're doing, and remember: if you use AES it only supports key sizes of 16, 24 or 32 bytes.

You either need to provide exactly that amount or you derive the key from what you type in.

Get a Cookie

The GetCookie returns cookie's value by its name, returns empty string if nothing was found.

GetCookie(name string, options ...CookieOption) string

If you want more than the value then use the following instead:

cookie, err := ctx.Request().Cookie("name")

Get all Cookies

The ctx.Request().Cookies() method returns a slice of all the available request cookies. Sometimes you want to modify them or perform an action on each one of them, the easiet way to do that is by the VisitAllCookies method.

VisitAllCookies(visitor func(name string, value string))

Remove a Cookie

The RemoveCookie method deletes a cookie by its name and path = "/", the root one.

Tip: change the cookie's path to the current one by providing the iris.CookieCleanPath Cookie Options, as : RemoveCookie("nname", iris.CookieCleanPath).

Also, note that the default behavior is to set its HttpOnly to true. It performs a removal of cookie based on the web standards.

RemoveCookie(name string, options ...CookieOption)