How to add JS/CSS from layout.xml only if multible conditions are met?

Question

I have three fields in admin config section that have to be checked. If at least one of them is set to true the files should load.

layout.xml

<reference name="head">
    <action method="addItem">
        <type>skin_js</type>
        <name>path/to/file1.js</name>
    </action>
    <action method="addItem">
        <type>skin_js</type>
        <name>path/to/file2.js</name>
    </action>
    ...
</reference>

Ideas:

1. add a helper for each file
2. add a new (hidden?) field to config and at sections save_before set value depending of the other fields
3. Extended ifconfig extension is already is installed, but no idea how to set up condtions

At the moment I prefer 2nd one ...

Any other ideas? Any suggestions?

Answer 1

Solved it this way for now:

Layout.xml

<action method="addItem" ifconfig="[section]/[group]/enabled">
    <type>skin_js</type>
    <name>path/to/file1.js</name>
</action>

config.xml

<adminhtml>
    <events>
        <admin_system_config_changed_section_[section]>
            <observers>
                <module_enabledisable>
                    <class>[module]/observer</class>
                    <method>setConfig</method>
                </module_enabledisable>
            </observers>
        </admin_system_config_changed_section_[section]>
    </events>
</adminhtml>

Observer.php

public function setModuleEnabledDisabled(Varien_Event_Observer $observer)
{
    if (!$website = $observer->getWebsite()) {
        $scope = 'default';
        $scopeId = 0;
    } elseif (!$store = $observer->getStore()) {
        $scope = 'websites';
        $scopeId = Mage::app()->getWebsite($website)->getId();
    } else {
        $scope = 'stores';
        $scopeId = Mage::app()->getStore($store)->getId();
    }

    if ($scope == 'websites') {
        $storeId = Mage::app()->getWebsite($website)->getDefaultStore()->getId();
    } else {
        $storeId = $scopeId;
    }

    $path = '[module]/[section]/';
    $value = Mage::getStoreConfigFlag($path . 'to_cart', $storeId)
          || Mage::getStoreConfigFlag($path . 'to_compare', $storeId)
          || Mage::getStoreConfigFlag($path . 'to_wishlist', $storeId);

    try {
        Mage::getConfig()->saveConfig($path . 'enabled', (int) $value, $scope, $scopeId);
    } catch (Exception $e) {
        Mage::log($e->getMessage());
    }
}

If you have any better Ideas ...