diff options
Diffstat (limited to 'vendor/swiftmailer/swiftmailer/doc/headers.rst')
| -rw-r--r-- | vendor/swiftmailer/swiftmailer/doc/headers.rst | 739 |
1 files changed, 739 insertions, 0 deletions
diff --git a/vendor/swiftmailer/swiftmailer/doc/headers.rst b/vendor/swiftmailer/swiftmailer/doc/headers.rst new file mode 100644 index 0000000..2c11c18 --- /dev/null +++ b/vendor/swiftmailer/swiftmailer/doc/headers.rst @@ -0,0 +1,739 @@ +Message Headers +=============== + +Sometimes you'll want to add your own headers to a message or modify/remove +headers that are already present. You work with the message's HeaderSet to do +this. + +Header Basics +------------- + +All MIME entities in Swift Mailer -- including the message itself -- +store their headers in a single object called a HeaderSet. This HeaderSet is +retrieved with the ``getHeaders()`` method. + +As mentioned in the previous chapter, everything that forms a part of a message +in Swift Mailer is a MIME entity that is represented by an instance of +``Swift_Mime_MimeEntity``. This includes -- most notably -- the message object +itself, attachments, MIME parts and embedded images. Each of these MIME entities +consists of a body and a set of headers that describe the body. + +For all of the "standard" headers in these MIME entities, such as the +``Content-Type``, there are named methods for working with them, such as +``setContentType()`` and ``getContentType()``. This is because headers are a +moderately complex area of the library. Each header has a slightly different +required structure that it must meet in order to comply with the standards that +govern email (and that are checked by spam blockers etc). + +You fetch the HeaderSet from a MIME entity like so: + +.. code-block:: php + + $message = Swift_Message::newInstance(); + + // Fetch the HeaderSet from a Message object + $headers = $message->getHeaders(); + + $attachment = Swift_Attachment::fromPath('document.pdf'); + + // Fetch the HeaderSet from an attachment object + $headers = $attachment->getHeaders(); + +The job of the HeaderSet is to contain and manage instances of Header objects. +Depending upon the MIME entity the HeaderSet came from, the contents of the +HeaderSet will be different, since an attachment for example has a different +set of headers to those in a message. + +You can find out what the HeaderSet contains with a quick loop, dumping out +the names of the headers: + +.. code-block:: php + + foreach ($headers->getAll() as $header) { + printf("%s<br />\n", $header->getFieldName()); + } + + /* + Content-Transfer-Encoding + Content-Type + MIME-Version + Date + Message-ID + From + Subject + To + */ + +You can also dump out the rendered HeaderSet by calling its ``toString()`` +method: + +.. code-block:: php + + echo $headers->toString(); + + /* + Message-ID: <1234869991.499a9ee7f1d5e@swift.generated> + Date: Tue, 17 Feb 2009 22:26:31 +1100 + Subject: Awesome subject! + From: sender@example.org + To: recipient@example.org + MIME-Version: 1.0 + Content-Type: text/plain; charset=utf-8 + Content-Transfer-Encoding: quoted-printable + */ + +Where the complexity comes in is when you want to modify an existing header. +This complexity comes from the fact that each header can be of a slightly +different type (such as a Date header, or a header that contains email +addresses, or a header that has key-value parameters on it!). Each header in the +HeaderSet is an instance of ``Swift_Mime_Header``. They all have common +functionality, but knowing exactly what type of header you're working with will +allow you a little more control. + +You can determine the type of header by comparing the return value of its +``getFieldType()`` method with the constants ``TYPE_TEXT``, +``TYPE_PARAMETERIZED``, ``TYPE_DATE``, ``TYPE_MAILBOX``, ``TYPE_ID`` and +``TYPE_PATH`` which are defined in ``Swift_Mime_Header``. + + +.. code-block:: php + + foreach ($headers->getAll() as $header) { + switch ($header->getFieldType()) { + case Swift_Mime_Header::TYPE_TEXT: $type = 'text'; + break; + case Swift_Mime_Header::TYPE_PARAMETERIZED: $type = 'parameterized'; + break; + case Swift_Mime_Header::TYPE_MAILBOX: $type = 'mailbox'; + break; + case Swift_Mime_Header::TYPE_DATE: $type = 'date'; + break; + case Swift_Mime_Header::TYPE_ID: $type = 'ID'; + break; + case Swift_Mime_Header::TYPE_PATH: $type = 'path'; + break; + } + printf("%s: is a %s header<br />\n", $header->getFieldName(), $type); + } + + /* + Content-Transfer-Encoding: is a text header + Content-Type: is a parameterized header + MIME-Version: is a text header + Date: is a date header + Message-ID: is a ID header + From: is a mailbox header + Subject: is a text header + To: is a mailbox header + */ + +Headers can be removed from the set, modified within the set, or added to the +set. + +The following sections show you how to work with the HeaderSet and explain the +details of each implementation of ``Swift_Mime_Header`` that may +exist within the HeaderSet. + +Header Types +------------ + +Because all headers are modeled on different data (dates, addresses, text!) +there are different types of Header in Swift Mailer. Swift Mailer attempts to +categorize all possible MIME headers into more general groups, defined by a +small number of classes. + +Text Headers +~~~~~~~~~~~~ + +Text headers are the simplest type of Header. They contain textual information +with no special information included within it -- for example the Subject +header in a message. + +There's nothing particularly interesting about a text header, though it is +probably the one you'd opt to use if you need to add a custom header to a +message. It represents text just like you'd think it does. If the text +contains characters that are not permitted in a message header (such as new +lines, or non-ascii characters) then the header takes care of encoding the +text so that it can be used. + +No header -- including text headers -- in Swift Mailer is vulnerable to +header-injection attacks. Swift Mailer breaks any attempt at header injection by +encoding the dangerous data into a non-dangerous form. + +It's easy to add a new text header to a HeaderSet. You do this by calling the +HeaderSet's ``addTextHeader()`` method. + +.. code-block:: php + + $message = Swift_Message::newInstance(); + + $headers = $message->getHeaders(); + + $headers->addTextHeader('Your-Header-Name', 'the header value'); + +Changing the value of an existing text header is done by calling it's +``setValue()`` method. + +.. code-block:: php + + $subject = $message->getHeaders()->get('Subject'); + + $subject->setValue('new subject'); + +When output via ``toString()``, a text header produces something like the +following: + +.. code-block:: php + + $subject = $message->getHeaders()->get('Subject'); + + $subject->setValue('amazing subject line'); + + echo $subject->toString(); + + /* + + Subject: amazing subject line + + */ + +If the header contains any characters that are outside of the US-ASCII range +however, they will be encoded. This is nothing to be concerned about since +mail clients will decode them back. + +.. code-block:: php + + $subject = $message->getHeaders()->get('Subject'); + + $subject->setValue('contains – dash'); + + echo $subject->toString(); + + /* + + Subject: contains =?utf-8?Q?=E2=80=93?= dash + + */ + +Parameterized Headers +~~~~~~~~~~~~~~~~~~~~~ + +Parameterized headers are text headers that contain key-value parameters +following the textual content. The Content-Type header of a message is a +parameterized header since it contains charset information after the content +type. + +The parameterized header type is a special type of text header. It extends the +text header by allowing additional information to follow it. All of the methods +from text headers are available in addition to the methods described here. + +Adding a parameterized header to a HeaderSet is done by using the +``addParameterizedHeader()`` method which takes a text value like +``addTextHeader()`` but it also accepts an associative array of +key-value parameters. + +.. code-block:: php + + $message = Swift_Message::newInstance(); + + $headers = $message->getHeaders(); + + $headers->addParameterizedHeader( + 'Header-Name', 'header value', + array('foo' => 'bar') + ); + +To change the text value of the header, call it's ``setValue()`` method just as +you do with text headers. + +To change the parameters in the header, call the header's ``setParameters()`` +method or the ``setParameter()`` method (note the pluralization). + +.. code-block:: php + + $type = $message->getHeaders()->get('Content-Type'); + + // setParameters() takes an associative array + $type->setParameters(array( + 'name' => 'file.txt', + 'charset' => 'iso-8859-1' + )); + + // setParameter() takes two args for $key and $value + $type->setParameter('charset', 'iso-8859-1'); + +When output via ``toString()``, a parameterized header produces something like +the following: + +.. code-block:: php + + $type = $message->getHeaders()->get('Content-Type'); + + $type->setValue('text/html'); + $type->setParameter('charset', 'utf-8'); + + echo $type->toString(); + + /* + + Content-Type: text/html; charset=utf-8 + + */ + +If the header contains any characters that are outside of the US-ASCII range +however, they will be encoded, just like they are for text headers. This is +nothing to be concerned about since mail clients will decode them back. +Likewise, if the parameters contain any non-ascii characters they will be +encoded so that they can be transmitted safely. + +.. code-block:: php + + $attachment = Swift_Attachment::newInstance(); + + $disp = $attachment->getHeaders()->get('Content-Disposition'); + + $disp->setValue('attachment'); + $disp->setParameter('filename', 'report–may.pdf'); + + echo $disp->toString(); + + /* + + Content-Disposition: attachment; filename*=utf-8''report%E2%80%93may.pdf + + */ + +Date Headers +~~~~~~~~~~~~ + +Date headers contains an RFC 2822 formatted date (i.e. what PHP's ``date('r')`` +returns). They are used anywhere a date or time is needed to be presented as a +message header. + +The data on which a date header is modeled is simply a UNIX timestamp such as +that returned by ``time()`` or ``strtotime()``. The timestamp is used to create +a correctly structured RFC 2822 formatted date such as +``Tue, 17 Feb 2009 22:26:31 +1100``. + +The obvious place this header type is used is in the ``Date:`` header of the +message itself. + +It's easy to add a new date header to a HeaderSet. You do this by calling +the HeaderSet's ``addDateHeader()`` method. + +.. code-block:: php + + $message = Swift_Message::newInstance(); + + $headers = $message->getHeaders(); + + $headers->addDateHeader('Your-Header-Name', strtotime('3 days ago')); + +Changing the value of an existing date header is done by calling it's +``setTimestamp()`` method. + +.. code-block:: php + + $date = $message->getHeaders()->get('Date'); + + $date->setTimestamp(time()); + +When output via ``toString()``, a date header produces something like the +following: + +.. code-block:: php + + $date = $message->getHeaders()->get('Date'); + + echo $date->toString(); + + /* + + Date: Wed, 18 Feb 2009 13:35:02 +1100 + + */ + +Mailbox (e-mail address) Headers +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Mailbox headers contain one or more email addresses, possibly with +personalized names attached to them. The data on which they are modeled is +represented by an associative array of email addresses and names. + +Mailbox headers are probably the most complex header type to understand in +Swift Mailer because they accept their input as an array which can take various +forms, as described in the previous chapter. + +All of the headers that contain e-mail addresses in a message -- with the +exception of ``Return-Path:`` which has a stricter syntax -- use this header +type. That is, ``To:``, ``From:`` etc. + +You add a new mailbox header to a HeaderSet by calling the HeaderSet's +``addMailboxHeader()`` method. + +.. code-block:: php + + $message = Swift_Message::newInstance(); + + $headers = $message->getHeaders(); + + $headers->addMailboxHeader('Your-Header-Name', array( + 'person1@example.org' => 'Person Name One', + 'person2@example.org', + 'person3@example.org', + 'person4@example.org' => 'Another named person' + )); + +Changing the value of an existing mailbox header is done by calling it's +``setNameAddresses()`` method. + +.. code-block:: php + + $to = $message->getHeaders()->get('To'); + + $to->setNameAddresses(array( + 'joe@example.org' => 'Joe Bloggs', + 'john@example.org' => 'John Doe', + 'no-name@example.org' + )); + +If you don't wish to concern yourself with the complicated accepted input +formats accepted by ``setNameAddresses()`` as described in the previous chapter +and you only want to set one or more addresses (not names) then you can just +use the ``setAddresses()`` method instead. + +.. code-block:: php + + $to = $message->getHeaders()->get('To'); + + $to->setAddresses(array( + 'joe@example.org', + 'john@example.org', + 'no-name@example.org' + )); + +.. note:: + + Both methods will accept the above input format in practice. + +If all you want to do is set a single address in the header, you can use a +string as the input parameter to ``setAddresses()`` and/or +``setNameAddresses()``. + +.. code-block:: php + + $to = $message->getHeaders()->get('To'); + + $to->setAddresses('joe-bloggs@example.org'); + +When output via ``toString()``, a mailbox header produces something like the +following: + +.. code-block:: php + + $to = $message->getHeaders()->get('To'); + + $to->setNameAddresses(array( + 'person1@example.org' => 'Name of Person', + 'person2@example.org', + 'person3@example.org' => 'Another Person' + )); + + echo $to->toString(); + + /* + + To: Name of Person <person1@example.org>, person2@example.org, Another Person + <person3@example.org> + + */ + +ID Headers +~~~~~~~~~~ + +ID headers contain identifiers for the entity (or the message). The most +notable ID header is the Message-ID header on the message itself. + +An ID that exists inside an ID header looks more-or-less less like an email +address. For example, ``<1234955437.499becad62ec2@example.org>``. +The part to the left of the @ sign is usually unique, based on the current time +and some random factor. The part on the right is usually a domain name. + +Any ID passed to the header's ``setId()`` method absolutely MUST conform to +this structure, otherwise you'll get an Exception thrown at you by Swift Mailer +(a ``Swift_RfcComplianceException``). This is to ensure that the generated +email complies with relevant RFC documents and therefore is less likely to be +blocked as spam. + +It's easy to add a new ID header to a HeaderSet. You do this by calling +the HeaderSet's ``addIdHeader()`` method. + +.. code-block:: php + + $message = Swift_Message::newInstance(); + + $headers = $message->getHeaders(); + + $headers->addIdHeader('Your-Header-Name', '123456.unqiue@example.org'); + +Changing the value of an existing ID header is done by calling its +``setId()`` method:: + + $msgId = $message->getHeaders()->get('Message-ID'); + + $msgId->setId(time() . '.' . uniqid('thing') . '@example.org'); + +When output via ``toString()``, an ID header produces something like the +following: + +.. code-block:: php + + $msgId = $message->getHeaders()->get('Message-ID'); + + echo $msgId->toString(); + + /* + + Message-ID: <1234955437.499becad62ec2@example.org> + + */ + +Path Headers +~~~~~~~~~~~~ + +Path headers are like very-restricted mailbox headers. They contain a single +email address with no associated name. The Return-Path header of a message is +a path header. + +You add a new path header to a HeaderSet by calling the HeaderSet's +``addPathHeader()`` method. + +.. code-block:: php + + $message = Swift_Message::newInstance(); + + $headers = $message->getHeaders(); + + $headers->addPathHeader('Your-Header-Name', 'person@example.org'); + +Changing the value of an existing path header is done by calling its +``setAddress()`` method. + +.. code-block:: php + + $return = $message->getHeaders()->get('Return-Path'); + + $return->setAddress('my-address@example.org'); + +When output via ``toString()``, a path header produces something like the +following: + +.. code-block:: php + + $return = $message->getHeaders()->get('Return-Path'); + + $return->setAddress('person@example.org'); + + echo $return->toString(); + + /* + + Return-Path: <person@example.org> + + */ + +Header Operations +----------------- + +Working with the headers in a message involves knowing how to use the methods +on the HeaderSet and on the individual Headers within the HeaderSet. + +Adding new Headers +~~~~~~~~~~~~~~~~~~ + +New headers can be added to the HeaderSet by using one of the provided +``add..Header()`` methods. + +To add a header to a MIME entity (such as the message): + +Get the HeaderSet from the entity by via its ``getHeaders()`` method. + +* Add the header to the HeaderSet by calling one of the ``add..Header()`` + methods. + +The added header will appear in the message when it is sent. + +.. code-block:: php + + // Adding a custom header to a message + $message = Swift_Message::newInstance(); + $headers = $message->getHeaders(); + $headers->addTextHeader('X-Mine', 'something here'); + + // Adding a custom header to an attachment + $attachment = Swift_Attachment::fromPath('/path/to/doc.pdf'); + $attachment->getHeaders()->addDateHeader('X-Created-Time', time()); + +Retrieving Headers +~~~~~~~~~~~~~~~~~~ + +Headers are retrieved through the HeaderSet's ``get()`` and ``getAll()`` +methods. + +To get a header, or several headers from a MIME entity: + +* Get the HeaderSet from the entity by via its ``getHeaders()`` method. + +* Get the header(s) from the HeaderSet by calling either ``get()`` or + ``getAll()``. + +When using ``get()`` a single header is returned that matches the name (case +insensitive) that is passed to it. When using ``getAll()`` with a header name, +an array of headers with that name are returned. Calling ``getAll()`` with no +arguments returns an array of all headers present in the entity. + +.. note:: + + It's valid for some headers to appear more than once in a message (e.g. + the Received header). For this reason ``getAll()`` exists to fetch all + headers with a specified name. In addition, ``get()`` accepts an optional + numerical index, starting from zero to specify which header you want more + specifically. + +.. note:: + + If you want to modify the contents of the header and you don't know for + sure what type of header it is then you may need to check the type by + calling its ``getFieldType()`` method. + + .. code-block:: php + + $headers = $message->getHeaders(); + + // Get the To: header + $toHeader = $headers->get('To'); + + // Get all headers named "X-Foo" + $fooHeaders = $headers->getAll('X-Foo'); + + // Get the second header named "X-Foo" + $foo = $headers->get('X-Foo', 1); + + // Get all headers that are present + $all = $headers->getAll(); + +Check if a Header Exists +~~~~~~~~~~~~~~~~~~~~~~~~ + +You can check if a named header is present in a HeaderSet by calling its +``has()`` method. + +To check if a header exists: + +* Get the HeaderSet from the entity by via its ``getHeaders()`` method. + +* Call the HeaderSet's ``has()`` method specifying the header you're looking + for. + +If the header exists, ``true`` will be returned or ``false`` if not. + +.. note:: + + It's valid for some headers to appear more than once in a message (e.g. + the Received header). For this reason ``has()`` accepts an optional + numerical index, starting from zero to specify which header you want to + check more specifically. + + .. code-block:: php + + $headers = $message->getHeaders(); + + // Check if the To: header exists + if ($headers->has('To')) { + echo 'To: exists'; + } + + // Check if an X-Foo header exists twice (i.e. check for the 2nd one) + if ($headers->has('X-Foo', 1)) { + echo 'Second X-Foo header exists'; + } + +Removing Headers +~~~~~~~~~~~~~~~~ + +Removing a Header from the HeaderSet is done by calling the HeaderSet's +``remove()`` or ``removeAll()`` methods. + +To remove an existing header: + +* Get the HeaderSet from the entity by via its ``getHeaders()`` method. + +* Call the HeaderSet's ``remove()`` or ``removeAll()`` methods specifying the + header you want to remove. + +When calling ``remove()`` a single header will be removed. When calling +``removeAll()`` all headers with the given name will be removed. If no headers +exist with the given name, no errors will occur. + +.. note:: + + It's valid for some headers to appear more than once in a message (e.g. + the Received header). For this reason ``remove()`` accepts an optional + numerical index, starting from zero to specify which header you want to + check more specifically. For the same reason, ``removeAll()`` exists to + remove all headers that have the given name. + + .. code-block:: php + + $headers = $message->getHeaders(); + + // Remove the Subject: header + $headers->remove('Subject'); + + // Remove all X-Foo headers + $headers->removeAll('X-Foo'); + + // Remove only the second X-Foo header + $headers->remove('X-Foo', 1); + +Modifying a Header's Content +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +To change a Header's content you should know what type of header it is and then +call it's appropriate setter method. All headers also have a +``setFieldBodyModel()`` method that accepts a mixed parameter and delegates to +the correct setter. + +To modify an existing header: + +* Get the HeaderSet from the entity by via its ``getHeaders()`` method. + +* Get the Header by using the HeaderSet's ``get()``. + +* Call the Header's appropriate setter method or call the header's + ``setFieldBodyModel()`` method. + +The header will be updated inside the HeaderSet and the changes will be seen +when the message is sent. + +.. code-block:: php + + $headers = $message->getHeaders(); + + // Change the Subject: header + $subj = $headers->get('Subject'); + $subj->setValue('new subject here'); + + // Change the To: header + $to = $headers->get('To'); + $to->setNameAddresses(array( + 'person@example.org' => 'Person', + 'thing@example.org' + )); + + // Using the setFieldBodyModel() just delegates to the correct method + // So here to calls setNameAddresses() + $to->setFieldBodyModel(array( + 'person@example.org' => 'Person', + 'thing@example.org' + )); |