With sincere gratitude from Webel IT Australia to Drupal CMS. Although it's not perfect, it is very powerful and is very popular with good reason.
Some hooks are also explored in more depth in dedicated child pages here.
You should also know about the Callbacks function signature patterns:
Drupal's API sometimes uses callback functions to allow you to define how some type of processing happens. A callback is a function with a defined signature, which you define in a module. Then you pass the function name as a parameter to a Drupal API function or return it as part of a hook implementation return value, and your function is called at an appropriate time. For instance, when setting up batch processing you might need to provide a callback function for each processing step and/or a callback for when processing is finished; you would do that by defining these functions and passing their names into the batch setup function.
Callback function signatures, like hook definitions, are described by creating and documenting dummy functions in a *.api.php file; normally, the dummy callback function's name should start with "callback_", and you should document the parameters and return value and provide a sample function body. Then your API documentation can refer to this callback function in its documentation. A user of your API can usually name their callback function anything they want, although a standard name would be to replace "callback_" with the module name.
This educational site is brought to you by Webel IT Australia, experts in database-driven web technology for industry, engineering, education and science. Webel is one of Australia's most experienced Drupal CMS web site specialists.
'It ain't necessarily so,
It ain't necessarily so,
The t'ings dat yo' li'ble,
To read in de [Drupal6/7] Bible,
It ain't necessarily so.'
Heresy: Doctrine rejected as false by religious authorities.
Logical fallacy: Appeal to popularity, Argumentum ad populum.
© Copyright 2001 - 2016 Webel IT Australia (ABN: 67 677 268 579). All rights reserved (except as specified below).
PHP code examples from Webel IT Australia on this site are distributed under the GNU General Public License.
Excludes text and code snippets from Drupal.org quoted for educational purposes.
Drupal’s online documentation is © 2000-2014 by the individual contributors and can be used in accordance with the Creative Commons License, Attribution-ShareAlike 2.0.
PHP code from Drupal.org is distributed under the GNU General Public License.
Drupal® is a registered trademark of Dries Buytaert.
Text quoted from Wikipedia for educational purposes is made available under the Creative Commons Attribution-ShareAlike License.
Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.
Site developed by Webel IT Australia.