These are functions which can be used from within plugins' files.

This function is used to register plugin in Instant Update's Plugin System (further: IUPS). It accepts two arguments, first is Plugin ID, which is actually file name of main plugin file, and second is array of plugin data.

Exists from version: 3.0

//set plugin id as file name of plugin
$plugin_id = basename(__FILE__);
 
//some plugin data
$data['name'] = "IU Footer ad";
$data['description'] = "Advertise Instant Update in the footer of your website.";
$data['author'] = "Instant Update team";
$data['url'] = "http://www.instant-update.com/";
 
//register plugin to IUPS
if (function_exists('register_plugin')) {
	register_plugin($plugin_id, $data);
}

This function is used to attach plugin function to IUPS. It accepts two arguments, first is hook name and second is name of the function you want to attach to the hook.

Exists from version: 3.0

if (function_exists('add_hook')) {
	add_hook('iu_page_footer','iufooterad_add2footer');
	add_hook('below_dashboard','iufooterad_add2dash');
}

Function to add navigation menu item to the automatically generated menus. All items added via this function will be added right before last menu item added by Instant Update's automatic menus.

This function can be used only in plugin functions which are attached to following hooks: iu_navigation_menu

Exists from version: 3.0

function nav_link() {
	add_menu_item("Google", "http://www.google.com/");
}

Function to add navigation menu item to the menus used in Instant Update administration.

This function can be used only in plugin functions which are attached to following hooks: below_dashboard, above_dashboard, main_nav

Exists from version: 3.0

function iufooterad_add2dash() {
	if (iu_is_admin()) {
		add_menu_item("Configure footer Ad", "plugins/iu-footer/iu-footer-config.php", IU_LINK_POPUP, "Footer AD administration", 500, 450);
	}
}

Function to add navigation menu item to the menus used in Instant Update sidebar (in administration panel).

This function can be used only in plugin functions which are attached to following hooks: sidebar

Exists from version: 3.1

function iufooterad_add2sidebar() {
	if (iu_is_admin()) {
		add_menu_item("Configure footer Ad", "plugins/iu-footer/iu-footer-config.php", "plugins/iu-footer/icon.gif", IU_LINK_POPUP, "Footer AD administration", 500, 450);
	}
}

This function accepts no arguments and returns TRUE or FALSE if currently logged in user is administrator user or not, respectively.

Exists from version: 3.0

NONE

function iufooterad_add2dash() {
	if (iu_is_admin()) {
		add_menu_item("Configure footer Ad", "plugins/iu-footer/iu-footer-config.php", IU_LINK_POPUP, "Footer AD administration", 500, 450);
	}
}

This function accepts no arguments and returns TRUE or FALSE if current web site visitor is logged in into Instant Update administration panel or not, respectively.

Exists from version: 3.0

NONE

function plugin_function() {
	if (iu_is_loggedin()) {
		echo "You are logged in :)";
	}
	else {
		echo "You are not logged in :(";
	}
}

This function returns value of a setting in MySQL database. If there is no such setting in MySQL database, it'll return default value (if specified, otherwise it'll return boolean false).

Exists from version: 3.0, modified in 3.1

if (!GetSettingsValue('iu_footer_url')) { $iu_footer_url = 'http://www.instant-update.com/'; }
else { $iu_footer_url = GetSettingsValue('iu_footer_url'); }

From version 3.1 you can specify default value which will be returned if there is no value for our setting (in this example it's iu_footer_url) in database:

$iu_footer_url = GetSettingsValue('iu_footer_url', 'http://www.instant-update.com/');

This function removes a setting in MySQL database. If there is no such setting in MySQL database, it'll return FALSE.

Exists from version: 3.0

if (isset($_GET['uninstall']) && iu_is_admin()) {
	RemoveSetting('iu_footer_url');
	RemoveSetting('iu_footer_image_alt');
	RemoveSetting('iu_footer_image');
	RemoveSetting('iu_footer_image_align');
	RemoveSetting('iu_footer_image_target');
	RemoveSetting('iu_footer_active');
	die("<p>IU footer Ad data removed! Now you can remove folder iu-footer from your plugins directory!</p>");
}

This function updates setting value in MySQL database. If there is no such setting in MySQL database, it'll create it.

Exists from version: 3.0

if (GetSettingsValue('iu_footer_image_target') == false) {
	WriteSettingsValue('iu_footer_image_target', '_blank','select','_blank|_self|_top');
}

This function returns HTML code of HTML form field based on setting type in MySQL database.

Exists from version: 3.0

echo CreateSettingFormField('iu_footer_active','<br />');

Function to add reference to external JS file in HEAD of both Instant Update (internal) pages and Instant Update powered web pages.

This function can be used only in plugin functions which are attached to following hooks: meta, iu_page_meta

Exists from version: 3.1

function plugin_meta() {
	insert_js('path/to/scripts.js');
}

Function to add reference to external CSS file in HEAD of both Instant Update (internal) pages and Instant Update powered web pages.

This function should be used in plugin functions which are attached to following hooks: meta, iu_page_meta

Exists from version: 3.1

function plugin_meta() {
	insert_css('path/to/styles.css');
	insert_css('path/to/styles2.css', array('screen','handheld'));
	insert_css('http://www.website.com/path/to/styles.css', 'screen, print');
}

Function to set minimum version of IU required for plugin to work. If plugin is loaded in older version than required, it will not work and it will display warning message.

Note
Because this function is not available in older versions of IU, it is wise to check if function exists before you make a call to the function.

Exists from version: 3.1

if (function_exists('iu_plugin_require_version')) {
	iu_plugin_require_version(3.1, $plugin_id);
}
else die("({$data[name]}) Please upgrade Instant Update to the latest version.");

Returns Instant Update version number, as string or float.

Exists from version: 3.1

echo "You are using Instant Update version: " . iu_version(); // This will return "You are using Instant Update version: 3.1"
 
if (iu_version(true) < 3.2) echo "Your Instant Update version is lower than 3.2"; // If we want to compare versions or to do some computing, we want to get IU version as float

Sends HTTP HEADER with Content-type and charset information. If headers are already sent it will return false, otherwise it'll return true.

Exists from version: 3.1

iu_set_encoding('text/javascript'); //if you're dumping JavaScript code from within PHP script