Plugin only returns fields that were overridden, not the Yoast defaults

[ashleahhill]

I know that this plugin hasn't been tested with this version of WP, but I thought I'd post this in case you plan on updating. Yoast itself has vague plans to support the WP REST API themselves, but no timeline that I can see. Yoast/wordpress-seo#3061

• WP version: 4.8.1
• Yoast version: 5.4

What's happening

Yoast data is coming back empty for every field.

{
id: 141,
date: "2017-09-06T16:38:35",
date_gmt: "2017-09-06T16:38:35",
...
yoast: {
    focuskw: "",
    title: "",
    metadesc: "",
    linkdex: "",
    metakeywords: "",
    meta-robots-noindex: "",
    meta-robots-nofollow: "",
    meta-robots-adv: "",
    canonical: "",
    redirect: "",
    opengraph-title: "",
    opengraph-description: "",
    opengraph-image: "",
    twitter-title: "",
    twitter-description: "",
    twitter-image: ""
}
}

What's Expected

The Yoast fields should contain the values the plugin would normally add to the HEAD of the document.

<title>Test Page Stuff - name name</title>

<!-- This site is optimized with the Yoast SEO plugin v5.4 - https://yoast.com/wordpress/plugins/seo/ -->
<!-- Admin only notice: this page doesn't show a meta description because it doesn't have one, either write it for this page specifically or go into the SEO -> Titles menu and set up a template. -->
<meta name="robots" content="noindex,follow">
<link rel="canonical" href="http://vccw.dev/test-page-stuff/">
<meta property="og:locale" content="en_US">
<meta property="og:type" content="article">
<meta property="og:title" content="Test Page Stuff - name name">
<meta property="og:description" content="lakjfao;wueoc orjaocnugnzlosio;ohgrhoi">
<meta property="og:url" content="http://vccw.dev/test-page-stuff/">
<meta property="og:site_name" content="name name">
<meta property="article:publisher" content="https://www.facebook.com/namename/">
<meta name="twitter:card" content="summary">
<meta name="twitter:description" content="lakjfao;wueoc orjaocnugnzlosio;ohgrhoi">
<meta name="twitter:title" content="Test Page Stuff - name name">
<meta name="twitter:site" content="@namename">
<meta name="twitter:creator" content="@namename">
<script type="application/ld+json">{"@context":"http:\/\/schema.org","@type":"WebSite","@id":"#website","url":"http:\/\/vccw.dev\/","name":"name name","alternateName":"name name at the name Arcade in Norfolk, VA","potentialAction":{"@type":"SearchAction","target":"http:\/\/vccw.dev\/?s={search_term_string}","query-input":"required name=search_term_string"}}</script>
<script type="application/ld+json">{"@context":"http:\/\/schema.org","@type":"Organization","url":"http:\/\/vccw.dev\/test-page-stuff\/","sameAs":["https:\/\/www.facebook.com\/namename\/","https:\/\/www.instagram.com\/namename\/","https:\/\/twitter.com\/namename"],"@id":"#organization","name":"name name","logo":""}</script>
<!-- / Yoast SEO plugin. -->



</head>

If I override the defaults in the Yoast plugin on the page, then the new value shows up.

[leup]

Okay, so I did a really dirty hack to add some metatags values to the REST output. (Only the ones I needed and care about mostly).
You cand find my fork here:
https://github.com/Glasshouse/wp-api-yoast-meta

I had to extend and overrides some Yoast core classes to be able to get some values instead of writing them to HTML document. It seems like there is a lot to do to improve Yoast developer-friendly usability.

[Poliuk]

@leup thanks a lot for your contribution. I've been trying to add the yoast title for the categories and the tags, but I haven't been able to make it work yet.

Do you think you could help me? I've been trying here wp-pwa@bbc11e8

These are the fields I want to add to the REST API

[leup]

@Poliuk I would very much like to help you but I am overflowing with job right now and it could take (a lot of) days before I got any spare time.

[Poliuk]

@leup Thanks for your prompt answer 😊 I'll keep trying to finish my part, I'll let you know :)

[Poliuk]

Finally found the way, I'll post it here just in case someone lands in this issue:

    // Category
register_rest_field( 'category',
        'yoast',
        array(
            'get_callback'    => array( $this, 'wp_api_encode_yoast_category' ),
            'update_callback' => null,
            'schema'          => null,
        )
    );

  	// Tag
  register_rest_field( 'tag',
        'yoast',
        array(
            'get_callback'    => array( $this, 'wp_api_encode_yoast_tag' ),
            'update_callback' => null,
            'schema'          => null,
        )
    );

function wp_api_encode_taxonomy (){
	include __DIR__ . '/classes/class-frontend.php';

	$wpseo_frontend = WPAPI_WPSEO_Frontend::get_instance();
	$yoastMeta = array(
		'yoast_wpseo_title' => $wpseo_frontend->get_taxonomy_title(),
		'yoast_wpseo_metadesc' => $wpseo_frontend->metadesc(false),
	);
	return (array) $yoastMeta;
}

function wp_api_encode_yoast_category($category) {
	$args=array(
  	'cat' => $category['id'],
	);
	$GLOBALS['wp_query'] = new WP_Query( $args );

	return $this->wp_api_encode_taxonomy();
}

function wp_api_encode_yoast_tag($tag){
	$args=array(
		'tag_id' => $tag['id'],
	);
	$GLOBALS['wp_query'] = new WP_Query( $args );

	return $this->wp_api_encode_taxonomy();
}

[hsimah]

See #5 for a nicely laid out solution to this issue.
If you go to the forked repository and download master as a zip you can upload it as a plugin and it functions perfectly with the Yoast generated values.