Hide top admin menu

Question

How to hide top menu and disable my custom module, if field "enabled" is 0(no). Magento version 1.9

<?xml version="1.0"?>
<config>
<tabs>
    <plumrocket translate="title">
        <label>Plumrocket</label>
        <sort_order>10</sort_order>
    </plumrocket>
</tabs>
<sections>
    <productlabels translate="title">
        <label>Product Labels</label>
        <tab>plumrocket</tab>
        <backend_model>productlabels/system</backend_model>
        <show_in_default>1</show_in_default>
        <show_in_Website>1</show_in_Website>
        <show_in_store>1</show_in_store>
        <groups>
            <global>
                <label translate="title">Settings</label>
                <sort_order>10</sort_order>
                <show_in_default>1</show_in_default>
                <show_in_Website>1</show_in_Website>
                <show_in_store>1</show_in_store>
                <fields>
                    <enabled>
                        <label translate="title">Enabled</label>
                        <frontend_type>select</frontend_type>
                        <source_model>adminhtml/system_config_source_yesno</source_model>
                        <sort_order>20</sort_order>
                        <show_in_default>1</show_in_default>
                        <show_in_Website>1</show_in_Website>
                        <show_in_store>1</show_in_store>
                    </enabled>
                </fields>
            </global>
        </groups>
    </productlabels>
</sections>

Answer 1

In your etc/adminhtml.xml, in which you define your top menu item, you can use the <depends></depends> node in the same way as you would do in system.xml to make one option depend on another one.

This means, in your etc/adminhtml.xml you can do something like this (note: you need to adapt vendor_module by yourself as it is not declared in your question):

<adminhtml>
    <menu>
        <vendor_module module="vendor_module">
            <depends>
                <config>productlabels/global/enabled</config> <!-- as defined in your system.xml -->
            </depends>
            <title>Vendor Module Title</title>
            <sort_order>71</sort_order>               
            <action>vendor_module/adminhtml_something</action>
        </vendor_module>
    </menu>
</adminhtml>

The magic part in this is the <depends><config>productlabels/global/enabled</config></depends> which makes Magento check for whether this option is set to Yes or No in System -> Configuration -> Your Module -> Your Option.

Important note: This does not mean that your controller action is not reachable! If you want to hinder the user to reach the page behind by entering its direct URL you'll have to cover this separately.

Answer 2

This is not the top menu, it's configuration settings, but you can hide them by commenting on the <tab> ... </ tab> tag. Then the Magento will not know which module these settings belong to. The top menu settings are in the <menu>