Construct schema.org meta script by appending text node

[westonruter]

I found on an environment that the Schema.org meta was being output empty as:

<script type="application/ld+json"></script>

When looking at the logs I saw an error:

PHP Warning: DOMDocument::createElement(): unterminated entity reference d=mm&r=g","width":200,"height":200}} in …/amp/includes/class-amp-theme-support.php on line 984

When looking up the docs for DOMDocument::createElement() I found that while it does take a second parameter for the value, it apparently does not do escaping (❓ ):

The value of the element. By default, an empty element will be created. The value can also be set later with DOMElement::$nodeValue.

The value is used verbatim except that the < and > entity references will escaped. Note that & has to be manually escaped; otherwise it is regarded as starting an entity reference. Also " won't be escaped.

This is even noted in the second example. This was causing problems for a value like, specifically for the ampersands in the URL:

{"@context":"http:\/\/schema.org","publisher":{"@type":"Organization","name":"WCEU 2018 AMP Demos"},"@type":"WebPage","mainEntityOfPage":"https:\/\/amp-demo.xwp.io\/","headline":"Home","datePublished":"2018-06-10T23:06:03+00:00","dateModified":"2018-06-10T23:06:03+00:00","author":{"@type":"Person","name":"Weston Ruter"},"image":{"@type":"ImageObject","url":"https:\/\/secure.gravatar.com\/avatar\/bb16e7904f2f335b6c9f524cc533d2d2?s=200&d=mm&r=g","width":200,"height":200}}

The issue is fixed if the text node is explicitly created and appended to the script element.

[kienstra]

Approved

Hi @westonruter,
This looks good, and works as expected.

Like you mentioned, with this PR, image URLs that have ampersands appear as expected. Like:

https://example.com/?foo=1&bar=2

I also saw that before this PR, an image URL with ampersands caused the schema.org data to not appear: