Load all child blocks in Adminhtml Head block

[elidrissidev]

Description (*)

First roadblock I encountered when creating the extension mentioned in #3219, I can't add a custom child block to admin head 😢, and since the content is dynamically created through calling PHP code I can't use addJs either.

I don't know why this change wasn't done before, maybe it caused some issue? but it seems to work fine for me.

Manual testing scenarios (*)

1. Go to layout xml of any module and try to add a child block to adminhtml head, in my case:

...
<default>
    <reference name="head">
        <block type="elidrissidev_debugbar/head" name="debugbar_head" />
    </reference>
</default>
...

Should be loaded after this change.

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All automated tests passed successfully (all builds are green)
• Add yourself to contributors list

[fballiano]

since the getchildhtml outputs all of the children if no name is passed, it seems good to me.

did a brief test and worked fine

[fballiano]

I wonder if there may be other blocks that were not printed before and that now get printed and that could cause problems.

[elidrissidev]

The only block I see is directory/js/optional_zip_countries.phtml which is being added to the head in multiple places. Just checked, there doesn't seem to be anything unusual, only optional_zip_countries and head.calendar are loaded inside the head.

[elidrissidev]

Do you think we should backport this to v19 for the next release?

[fballiano]

it wouldn't cause any harm, absolutely, but I think we shouldn't anyway :-)

[elidrissidev]

I found a workaround by observing core_block_abstract_to_html_after and appending the html when it's the Head block:

    public function addDebugbarHeadToAdminhtml(Varien_Event_Observer $observer)
    {
        $block = $observer->getEvent()->getBlock();

        if (!$block instanceof Mage_Page_Block_Html_Head) {
            return;
        }

        /** @var Varien_Object $transport */
        $transport = $observer->getEvent()->getTransport();
        $renderer = Mage::getSingleton('elidrissidev_debugbar/debugbar')
            ->getDebugbar()
            ->getJavascriptRenderer();

        $transport->setHtml($transport->getHtml() . $renderer->renderHead());
    }

Although not as clean, at least it doesn't require to rewrite the block.

[fballiano]

sure, but I think this PR still makes a lot of sense :-)

[luigifab]

Is there a general issue now?

do:

<?php echo $this->getChildHtml('debugbar_head') ?>
<?php echo $this->getChildHtml() ?>

and the debugbar is displayed 2x

do:

<?php echo $this->getChildHtml('debugbar_head') ?>
<?php echo $this->getChildHtml() ?>
<?php echo $this->getChildHtml() ?>

and the debugbar is displayed 3x

Or it's me? and it's already the time to travel again!

[elidrissidev]

@luigifab I think that's the intended behaviour, $this->getChildHtml() will return HTML for all children, whereas $this->getChildHtml('debugbar_head') will return HTML of debugbar_head block only.