6.38.1. How does Cookie work? #

Almost all website designers use Cookie in website design. Because they all want to provide users who browse the website with a more friendly and cultural browsing environment, and at the same time collect visitors’ information more accurately.

6.38.2. Write and read #

The Cookies collection is attached to the Response object and Request object, which needs to be preceded by Response or Request .

The syntax used to send Cookies to clients is usually:

When giving to the non-existent Cookies collection is set, it is created on the client, if the Cookies already exists, it will be replaced.

Because Cookies are sent to the client as part of the header information for HTTP transmission, so the code for sending Cookies to the client is usually placed before the tags in the HTML file sent to the browser.

If the user wants to read Cookies , you must use the Request object’s Cookies collection, which is used by:

It is important to note that only before the server has downloaded any data to the browser can the browser communicate with Server carry on Cookies collection of data exchange, once the browser starts to receive``Server`` downloaded data Cookies . The data exchange is stopped, and to avoid errors, add response.Buffer=True .

6.38.3. Properties of the collection #

• 1.``Expires`` attribute: this property is used to give Cookies set a deadline within which you can call the saved Cookies as long as you open theweb page. If the deadline has passed, Cookies is automatically deleted. Such as: setting Cookies valid until April 1, 2004, when it will be automatically deleted. If Cookies validity period isnot set, the life cycle starts from opening the browser to the end of closing the browser, the life cycle will end after each run, and the next run will start again.

• 2.``Domain`` attribute: this property defines the Cookies uniqueness of transmitting data. If only a certain Cookies transmit to``_blank”>`` for Sohu’s home page, you can use the following code:

• 3.``Path`` attribute: defined Cookies send only the specified path request, if Path property is not set, the default path of the application is used.

• 4. Secure attributes: specify in Cookies can it be read by the user.

• 5.``Name=Value`` : Cookies is set and retrieved in the form of key-value pairs.

6.38.4. Dealing with Cookies in Ruby #

You can create a file named cookie and store text information, send theinformation to the browser, and call the CGI.out to set up the head of cookie .

#!/usr/bin/rubyrequire"cgi"cgi=CGI.new("html4")cookie=CGI::Cookie.new('name'=>'mycookie','value'=>'Zara
Ali','expires'=>Time.now+3600)cgi.out('cookie'=>cookie)docgi.head+cgi.body{"Cookie
stored"}end

#!/usr/bin/rubyrequire"cgi"cgi=CGI.new("html4")cookie=cgi.
cookies['mycookie']cgi.out('cookie'=>cookie)docgi.head+cgi.body{cookie[0]}end