Topic: Plug-ins for Cutenews 1.5
The idea of plug-ins is that there are the functions hook() that pass the data meanings in the particular places of the original CuteNews code, and these data are handled by plug-ins' filters.
To show how the hooks work we can take for example the code for processing the news template from core.php:
list($output, $news_arr) = hook('template_replacer_news_before', array($output, $news_arr));
Here the hook is called for the function "template_replacer_news before" the changes of the constructions like {title}, {author} and so on.
Explanations: The array $news_arr is the data with the meanings of the current news, $output is the content of tpl-template, for example the content of Default.tpl.
The called hook has a name "template_replacer_news_before". This name is registered when plug-in initialization and can be used for calling other plug-ins,
i.e. if one plug-in registered the name "template_replacer_news_before" and another one did the same then the function of the first plug-in will be called primarily.
Let's create the first plug-in. Name it my_plugin.php and place in ./cdata/plugins directory.
Here are the the plug-in snippet:
<?php
/*
Connect the hook "template_replacer_news_before" with the function 'my_plugin_trnewsb'.
It means that while calling the hook ('template_replacer_news_before', $args) the function my_plugin_trnewsb() will be called that will have the parameter $data.
*/
add_hook('template_replacer_news_before', 'my_plugin_trnewsb');
function my_plugin_trnewsb($data)
{
// Here the $data is the array, that's why the hook will return the same array
return $data;
}
?>
As you can see the mechanism is quite easy. You need to register the hook and write for it the appropriate handler function.
You shouldn't forget to do a 'return' of the data meanings (modified probably) or you can have an incorrect input.
Let's write the new field for templates, for example the field "{show_php_version}"
<?php
add_hook('template_replacer_news_before', 'my_plugin_trnewsb');
function my_plugin_trnewsb($data)
{
// Unpack the data from the array
list($output, $news) = $data;
// Make a change of {show_php_version} to the meaning PHP_VERSION
$output = str_replace('{show_php_version}', 'PHP Version is '.PHP_VERSION, $output);
// Return the data to the code
return array($output, $news);
}
?>
Now add to the template code, for example to the Full Story the fragment {show_php_version}, then create news and see the PHP version data.
It's easy to make the additional menu in options with the help of plug-ins. Two hooks are responsible for this – "more_options" and "options_additional_actions".
The hook "more_options" is necessary for adding the links to the section Options, the second one processes the incoming data on ?mod=options&action=options.
An example:
Create the file add_options.php in ./cdata/plugins:
<?php
add_hook('more_options', 'aopt_menu');
add_hook('options_additional_actions', 'aopt_handler');
// The parameter $options is passed for this hook, we should add
function aopt_menu($options)
{
$PHP_SELF = PHP_SELF;
$options[] = array
(
'name' => lang('My plugin!', 'options'),
'url' => "$PHP_SELF?mod=options&action=my_more_options",
'access' => ACL_LEVEL_ADMIN,
);
return $options;
}
// The data aren't passed, we should use the global variables
function aopt_handler()
{
// Instead of the straight call $_GET you can use the function REQ
if (REQ('action','GET') == 'my_more_options')
msg('info', 'Hello!', lang("It's my FIRST plugin"));
}
?>
Now in Options there is a new menu 'My plugin!'. While clicking to it we will see the message "It's my FIRST plugin".
Good luck with creating of plug-ins!
CN Support team
