ZendHttpCookie and ZendHttpCookieJar

Introduction

Zend\Http\Cookie, as expected, is a class that represents an HTTP cookie. It provides methods for parsing HTTP response strings, collecting cookies, and easily accessing their properties. It also allows checking if a cookie matches against a specific scenario, IE a request URL, expiration time, secure connection, etc.

Zend\Http\CookieJar is an object usually used by Zend\Http\Client to hold a set of Zend\Http\Cookie objects. The idea is that if a Zend\Http\CookieJar object is attached to a Zend\Http\Client object, all cookies going from and into the client through HTTP requests and responses will be stored by the CookieJar object. Then, when the client will send another request, it will first ask the CookieJar object for all cookies matching the request. These will be added to the request headers automatically. This is highly useful in cases where you need to maintain a user session over consecutive HTTP requests, automatically sending the session ID cookies when required. Additionally, the Zend\Http\CookieJar object can be serialized and stored in $_SESSION when needed.

Instantiating ZendHttpCookie Objects

Instantiating a Cookie object can be done in two ways:

  • Through the constructor, using the following syntax: new Zend\Http\Cookie(string $name, string $value, string $domain, [int $expires, [string $path, [boolean $secure]]]);

    • $name: The name of the cookie (eg. ‘PHPSESSID’) (required)
    • $value: The value of the cookie (required)
    • $domain: The cookie’s domain (eg. ‘.example.com’) (required)
    • $expires: Cookie expiration time, as UNIX time stamp (optional, defaults to NULL). If not set, cookie will be treated as a ‘session cookie’ with no expiration time.
    • $path: Cookie path, eg. ‘/foo/bar/’ (optional, defaults to ‘/’)
    • $secure: Boolean, Whether the cookie is to be sent over secure (HTTPS) connections only (optional, defaults to boolean FALSE)
  • By calling the fromString($cookieStr, [$refUri, [$encodeValue]]) static method, with a cookie string as represented in the ‘Set-Cookie ‘HTTP response header or ‘Cookie’HTTP request header. In this case, the cookie value must already be encoded. When the cookie string does not contain a ‘domain’ part, you must provide a reference URI according to which the cookie’s domain and path will be set.

    The fromString() method accepts the following parameters:

    • $cookieStr: a cookie string as represented in the ‘Set-Cookie’HTTP response header or ‘Cookie’HTTP request header (required)
    • $refUri: a reference URI according to which the cookie’s domain and path will be set. (optional, defaults to parsing the value from the $cookieStr)
    • $encodeValue: If the value should be passed through urldecode. Also effects the cookie’s behavior when being converted back to a cookie string. (optional, defaults to true)
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    // First, using the constructor. This cookie will expire in 2 hours
    $cookie = new Zend\Http\Cookie('foo',
                                   'bar',
                                   '.example.com',
                                   time() + 7200,
                                   '/path');
    
    // You can also take the HTTP response Set-Cookie header and use it.
    // This cookie is similar to the previous one, only it will not expire, and
    // will only be sent over secure connections
    $cookie = Zend\Http\Cookie::fromString('foo=bar; domain=.example.com; ' .
                                           'path=/path; secure');
    
    // If the cookie's domain is not set, you have to manually specify it
    $cookie = Zend\Http\Cookie::fromString('foo=bar; secure;',
                                           'http://www.example.com/path');
    

Note

When instantiating a cookie object using the Zend\Http\Cookie::fromString() method, the cookie value is expected to be URL encoded, as cookie strings should be. However, when using the constructor, the cookie value string is expected to be the real, decoded value.

A cookie object can be transferred back into a string, using the __toString() magic method. This method will produce a HTTP request “Cookie” header string, showing the cookie’s name and value, and terminated by a semicolon (‘;’). The value will be URL encoded, as expected in a Cookie header:

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// Create a new cookie
$cookie = new Zend\Http\Cookie('foo',
                               'two words',
                               '.example.com',
                               time() + 7200,
                               '/path');

// Will print out 'foo=two+words;' :
echo $cookie->__toString();

// This is actually the same:
echo (string) $cookie;

// In PHP 5.2 and higher, this also works:
echo $cookie;

ZendHttpCookie getter methods

Once a Zend\Http\Cookie class is instantiated, it provides several getter methods to get the different properties of the HTTP cookie:

  • getName(): Get the name of the cookie
  • getValue(): Get the real, decoded value of the cookie
  • getDomain(): Get the cookie’s domain
  • getPath(): Get the cookie’s path, which defaults to ‘/’
  • getExpiryTime(): Get the cookie’s expiration time, as UNIX time stamp. If the cookie has no expiration time set, will return NULL.

Additionally, several boolean tester methods are provided:

  • isSecure(): Check whether the cookie is set to be sent over secure connections only. Generally speaking, if TRUE the cookie should only be sent over HTTPS.

  • isExpired(int $time = null): Check whether the cookie is expired or not. If the cookie has no expiration time, will always return TRUE. If $time is provided, it will override the current time stamp as the time to check the cookie against.

  • isSessionCookie(): Check whether the cookie is a “session cookie” - that is a cookie with no expiration time, which is meant to expire when the session ends.

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    // First, create the cookie
    $cookie =
        Zend\Http\Cookie::fromString('foo=two+words; ' +
                                     'domain=.example.com; ' +
                                     'path=/somedir; ' +
                                     'secure; ' +
                                     'expires=Wednesday, 28-Feb-05 20:41:22 UTC');
    
    echo $cookie->getName();   // Will echo 'foo'
    echo $cookie->getValue();  // will echo 'two words'
    echo $cookie->getDomain(); // Will echo '.example.com'
    echo $cookie->getPath();   // Will echo '/'
    
    echo date('Y-m-d', $cookie->getExpiryTime());
    // Will echo '2005-02-28'
    
    echo ($cookie->isExpired() ? 'Yes' : 'No');
    // Will echo 'Yes'
    
    echo ($cookie->isExpired(strtotime('2005-01-01') ? 'Yes' : 'No');
    // Will echo 'No'
    
    echo ($cookie->isSessionCookie() ? 'Yes' : 'No');
    // Will echo 'No'
    

ZendHttpCookie: Matching against a scenario

The only real logic contained in a Zend\Http\Cookie object, is in the match() method. This method is used to test a cookie against a given HTTP request scenario, in order to tell whether the cookie should be sent in this request or not. The method has the following syntax and parameters: Zend\Http\Cookie->match(mixed $uri, [boolean $matchSessionCookies, [int $now]]);

  • $uri: A Zend\Uri\Http object with a domain name and path to be checked. Optionally, a string representing a valid HTTP URL can be passed instead. The cookie will match if the URL‘s scheme (HTTP or HTTPS), domain and path all match.

  • $matchSessionCookies: Whether session cookies should be matched or not. Defaults to TRUE. If set to FALSE, cookies with no expiration time will never match.

  • $now: Time (represented as UNIX time stamp) to check a cookie against for expiration. If not specified, will default to the current time.

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    // Create the cookie object - first, a secure session cookie
    $cookie = Zend\Http\Cookie::fromString('foo=two+words; ' +
                                           'domain=.example.com; ' +
                                           'path=/somedir; ' +
                                           'secure;');
    
    $cookie->match('https://www.example.com/somedir/foo.php');
    // Will return true
    
    $cookie->match('http://www.example.com/somedir/foo.php');
    // Will return false, because the connection is not secure
    
    $cookie->match('https://otherexample.com/somedir/foo.php');
    // Will return false, because the domain is wrong
    
    $cookie->match('https://example.com/foo.php');
    // Will return false, because the path is wrong
    
    $cookie->match('https://www.example.com/somedir/foo.php', false);
    // Will return false, because session cookies are not matched
    
    $cookie->match('https://sub.domain.example.com/somedir/otherdir/foo.php');
    // Will return true
    
    // Create another cookie object - now, not secure, with expiration time
    // in two hours
    $cookie = Zend\Http\Cookie::fromString('foo=two+words; ' +
                                           'domain=www.example.com; ' +
                                           'expires='
                                           . date(DATE_COOKIE, time() + 7200));
    
    $cookie->match('http://www.example.com/');
    // Will return true
    
    $cookie->match('https://www.example.com/');
    // Will return true - non secure cookies can go over secure connections
    // as well!
    
    $cookie->match('http://subdomain.example.com/');
    // Will return false, because the domain is wrong
    
    $cookie->match('http://www.example.com/', true, time() + (3 * 3600));
    // Will return false, because we added a time offset of +3 hours to
    // current time
    

The ZendHttpCookieJar Class: Instantiation

In most cases, there is no need to directly instantiate a Zend\Http\CookieJar class. If you want to attach a new cookie jar to your Zend\Http\Client object, just call the ZendHttpClient->setCookieJar() method, and a new, empty cookie jar will be attached to your client. You could later get this cookie jar using ZendHttpClient->getCookieJar().

If you still wish to manually instantiate a CookieJar class, you can do so by calling “new ZendHttpCookieJar()” directly - the constructor method does not take any parameters. Another way to instantiate a CookieJar class is to use the static ZendHttpCookieJar::fromResponse() method. This method takes two parameters: a Zend\Http\Response object, and a reference URI, as either a string or a Zend\Uri\Http object. This method will return a new Zend\Http\CookieJar object, already containing the cookies set by the passed HTTP response. The reference URI will be used to set the cookie’s domain and path, if they are not defined in the Set-Cookie headers.

Adding Cookies to a ZendHttpCookieJar object

Usually, the Zend\Http\Client object you attached your CookieJar object to will automatically add cookies set by HTTP responses to your jar. if you wish to manually add cookies to your jar, this can be done by using two methods:

  • Zend\Http\CookieJar->addCookie($cookie[, $ref_uri]): Add a single cookie to the jar. $cookie can be either a Zend\Http\Cookie object or a string, which will be converted automatically into a Cookie object. If a string is provided, you should also provide $ref_uri - which is a reference URI either as a string or Zend\Uri\Http object, to use as the cookie’s default domain and path.
  • Zend\Http\CookieJar->addCookiesFromResponse($response, $ref_uri): Add all cookies set in a single HTTP response to the jar. $response is expected to be a Zend\Http\Response object with Set-Cookie headers. $ref_uri is the request URI, either as a string or a Zend\Uri\Http object, according to which the cookies’ default domain and path will be set.

Retrieving Cookies From a ZendHttpCookieJar object

Just like with adding cookies, there is usually no need to manually fetch cookies from a CookieJar object. Your Zend\Http\Client object will automatically fetch the cookies required for an HTTP request for you. However, you can still use 3 provided methods to fetch cookies from the jar object: getCookie(), getAllCookies(), and getMatchingCookies(). Additionnaly, iterating over the CookieJar will let you retrieve all the Zend\Http\Cookie objects from it.

It is important to note that each one of these methods takes a special parameter, which sets the return type of the method. This parameter can have 3 values:

  • Zend\Http\CookieJar::COOKIE_OBJECT: Return a Zend\Http\Cookie object. If the method returns more than one cookie, an array of objects will be returned.
  • Zend\Http\CookieJar::COOKIE_STRING_ARRAY: Return cookies as strings, in a “foo=bar” format, suitable for sending in a HTTP request “Cookie” header. If more than one cookie is returned, an array of strings is returned.
  • Zend\Http\CookieJar::COOKIE_STRING_CONCAT: Similar to COOKIE_STRING_ARRAY, but if more than one cookie is returned, this method will concatenate all cookies into a single, long string separated by semicolons (;), and return it. This is especially useful if you want to directly send all matching cookies in a single HTTP request “Cookie” header.

The structure of the different cookie-fetching methods is described below:

  • Zend\Http\CookieJar->getCookie($uri, $cookie_name[, $ret_as]): Get a single cookie from the jar, according to its URI (domain and path) and name. $uri is either a string or a Zend\Uri\Http object representing the URI. $cookie_name is a string identifying the cookie name. $ret_as specifies the return type as described above. $ret_type is optional, and defaults to COOKIE_OBJECT.

  • Zend\Http\CookieJar->getAllCookies($ret_as): Get all cookies from the jar. $ret_as specifies the return type as described above. If not specified, $ret_type defaults to COOKIE_OBJECT.

  • Zend\Http\CookieJar->getMatchingCookies($uri[, $matchSessionCookies[, $ret_as[, $now]]]): Get all cookies from the jar that match a specified scenario, that is a URI and expiration time.

    • $uri is either a Zend\Uri\Http object or a string specifying the connection type (secure or non-secure), domain and path to match against.
    • $matchSessionCookies is a boolean telling whether to match session cookies or not. Session cookies are cookies that have no specified expiration time. Defaults to TRUE.
    • $ret_as specifies the return type as described above. If not specified, defaults to COOKIE_OBJECT.
    • $now is an integer representing the UNIX time stamp to consider as “now” - that is any cookies who are set to expire before this time will not be matched. If not specified, defaults to the current time.

    You can read more about cookie matching here: this section.

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