How to prevent joomla empty modules from being rendered, even returning false?

Question

How to prevent Joomla empty modules from being rendered? To achieve this-

I have tried by returning false from module's entry file if there is no output. I have written following code in modules entry file eg mod_xyx.php

// Hide mod when no output.
if ( @no_output)
{
    return ;
}

It works for Joomla's default template but doesn't work for some template.

Answer 1

If you are 100% sure that your module output is empty, then your template may be adding a chrome to the module.

You can check how the JModuleHelper::renderModule generates the module output and (optionally) calls the template chrome.

https://github.com/joomla/joomla-cms/blob/staging/libraries/cms/module/helper.php#L176

Answer 2

I've encountered this in the past, and your answer is likely in your template files...you'll probably see that its checking if there is a count of modules - something like this from Protostar:

<?php if ($this->countModules('position-8')) : ?>
<!-- Begin Sidebar -->
<div id="sidebar" class="span3">
    <div class="sidebar-nav">
        <jdoc:include type="modules" name="position-8" style="xhtml" />
    </div>
</div>
<!-- End Sidebar -->
<?php endif; ?>

It doesn't consider whether there is output or not, so renders the module position regardless of what is/isn't rendered.