Exception #0 (Exception): Notice: Undefined variable: crumbs in /breadcrumbs.phtml on Custom Layout

Question

Ive created a new page template xml which looks like:

<layout xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_layout.xsd">
<update handle="empty"/>
<referenceContainer name="page.wrapper" htmlClass="site-wrapper" htmlId="magento">
    <container name="header.container" as="header_container" label="Page Header Container" htmlTag="header" htmlClass="page-header" htmlId="header" before="main.content"/>
    <container name="business.types.top" as="business_types_top" label="Business Types Top" after="header.container"/>
    <container name="business.types.bottom" as="business_types_bottom" label="Business Types Bottom" after="main.content"/>
    <container name="footer-container" as="footer" before="before.body.end" label="Page Footer Container" htmlTag="footer" htmlClass="page-footer" htmlId="footer"/>
</referenceContainer>
</layout>

And in my default.xml I'm trying to add the breadcrumbs.phtml to the business.types.top container like:

<referenceContainer name="business.types.top">
        <block class="Magento\Framework\View\Element\Template" name="home.breadcrumbs" template="Magento_Theme::html/breadcrumbs.phtml"></block>
</referenceContainer>

However I receive the following error?

1 exception(s):
Exception #0 (Exception): Notice: Undefined variable: crumbs in /templates/html/breadcrumbs.phtml on line 10.

Can anyone please advise on how I can get the breadcrumbs to work on this page?

Thanks

UPDATE: This is my breadcrumbs.phtml, which is working on other pages using the default page templates:

<?php if ($crumbs && is_array($crumbs)) : ?>
<section class="section-breadcrumbs">
<div class="container">
    <ul class="as-breadcrumbs">
        <li><a href="/" title="Home">Home</a></li>
        <?php foreach ($crumbs as $crumbName => $crumbInfo) : ?>
            <li class="item <?php /* @escapeNotVerified */ echo $crumbName ?>">
            <?php if ($crumbInfo['link']) : ?>
                <a href="<?php /* @escapeNotVerified */ echo $crumbInfo['link'] ?>">
                    <?php
                    if ($block->escapeHtml($crumbInfo['label']) != "Home") {
                        echo "Products";
                    } else {
                        echo $block->escapeHtml($crumbInfo['label']);
                    }
                    ?>
                </a>
            <?php elseif ($crumbInfo['last']) : ?>
                <p class="active"><?php echo $block->escapeHtml($crumbInfo['label']) ?></p>
            <?php else: ?>
                <?php echo $block->escapeHtml($crumbInfo['label']) ?>
            <?php endif; ?>
            </li>
        <?php endforeach; ?>
    </ul>
</div>

Answer 1

Try to change a condition inside your template file from:

<?php if ($crumbs && is_array($crumbs)) : ?>

to:

<?php if (!empty($crumbs) && is_array($crumbs)) : ?>

PS: Do not change core template, use own template file

UPDATE:

The $crumbs variable comes from the block Magento\Theme\Block\Html\Breadcrumbs from the method _toHtml:

/**
 * Render block HTML
 *
 * @return string
 */
protected function _toHtml()
{
    if (is_array($this->_crumbs)) {
        reset($this->_crumbs);
        $this->_crumbs[key($this->_crumbs)]['first'] = true;
        end($this->_crumbs);
        $this->_crumbs[key($this->_crumbs)]['last'] = true;
    }
    $this->assign('crumbs', $this->_crumbs);

    return parent::_toHtml();
}

where the $this->_crumbs is a $crumbs (in future). They are transformed in the Magento\Framework\View\Element\Template in the method fetchView on line ~255 :

$html = $templateEngine->render($this->templateContext, $fileName, $this->_viewVars); // crumbs stored in the _viewVars attribute

To add a crumbs you should use method Magento\Theme\Block\Html\Breadcrumbs::assign('crumbs', $arrayOfBreadcrumbs);:

/**
 * Assign variable
 *
 * @param   string|array $key
 * @param   mixed $value
 * @return  $this
 */
public function assign($key, $value = null)
{
    if (is_array($key)) {
        foreach ($key as $subKey => $subValue) {
            $this->assign($subKey, $subValue);
        }
    } else {
        $this->_viewVars[$key] = $value;
    }
    return $this;
}

I think you have no breadcrumbs on your page because you are using an empty layout (<update handle="empty"/>).

Answer 2

Please check crumbs variable in your /templates/html/breadcrumbs.phtml file. it should be $crumbs.