echo/website/content/guide/cookies.md

+++ title = "Cookies" description = "Handling cookie in Echo" [menu.side] name = "Cookies" parent = "guide" weight = 6 +++

Cookies

Cookie is a small piece of data sent from a website and stored in the user's web browser while the user is browsing. Every time the user loads the website, the browser sends the cookie back to the server to notify the user's previous activity. Cookies were designed to be a reliable mechanism for websites to remember stateful information (such as items added in the shopping cart in an online store) or to record the user's browsing activity (including clicking particular buttons, logging in, or recording which pages were visited in the past). Cookies can also store passwords and form content a user has previously entered, such as a credit card number or an address.

Cookie Attributes

Attribute	Optional
Name	No
Value	No
Path	Yes
Domain	Yes
Expires	Yes
Secure	Yes
HTTPOnly	Yes

Echo uses go standard http.Cookie object to add/retrieve cookies from the context received in the handler function.

Create a Cookie

func writeCookie(c echo.Context) error {
	cookie := new(http.Cookie)
	cookie.Name = "username"
	cookie.Value = "jon"
	cookie.Expires = time.Now().Add(24 * time.Hour)
	c.SetCookie(cookie)
	return c.String(http.StatusOK, "write a cookie")
}

• Cookie is created using new(http.Cookie).
• Attributes for the cookie are set assigning to the http.Cookie instance public attributes.
• Finally c.SetCookie(cookies) adds a Set-Cookie header in HTTP response.

Read a Cookie

func readCookie(c echo.Context) error {
	cookie, err := c.Cookie("username")
	if err != nil {
		return err
	}
	fmt.Println(cookie.Name)
	fmt.Println(cookie.Value)
	return c.String(http.StatusOK, "read a cookie")
}

• Cookie is read by name using c.Cookie("username") from the HTTP request.
• Cookie attributes are accessed using Getter function.

Read all Cookies

func readAllCookies(c echo.Context) error {
	for _, cookie := range c.Cookies() {
		fmt.Println(cookie.Name)
		fmt.Println(cookie.Value)
	}
	return c.String(http.StatusOK, "read all cookie")
}