Drupal 7 Module Development

Chapter 5
Tokens can also be 'chained'—a token can refer to another token which can refer
to yet another one. As an example, the token [node:author] contains the name
of a node's author, and the token [user:e-mail] contains the e-mail address of a
given user. To retrieve the e-mail address of a node's author, you can chain the two
together with the token [node:author:e-mail].
Module developers can also expose their own tokens for other module
developers to take advantage of. For more information on how to expose
tokens in your module, see the following sites:
http://api.drupal.org/api/function/hook_token_info/7
http://api.drupal.org/api/function/hook_tokens/7
Drupal's token system is extremely flexible and prevents site builders and developers
from having to replace information in site text every time it changes. So let's see how
we can use tokens in our module.
How do we know what tokens are available?
Drupal 7 does not include a user interface for browsing available
tokens, however the contributed Token module implements a very nice
JavaScript tree-like browser for them. You can download and install it
from the following site:
http://drupal.org/project/token
Additionally module developers can use the function token_info() to
get a structured array containing all the tokens in the system. This can be
parsed and/or displayed as desired.
Implementing tokens in your text
The obvious place where User Warn could use tokens is in the text of the outgoing
e-mails. Let's expand the very simple default text we included above, and also put it
into a constant, for easier module readability and maintainability. This will require
updating some of the previous code, but in the future we will only need to change
this information in one place.
define('USER_WARN_MAIL_TEXT',
'Hello [user:name],
We have been notified that you have posted comments on [site:name]
that are in violation of our terms of service. If this behavior
continues your account will be suspended.
Sincerely,
[site:name]');
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