One of the new WordPress 4.4 features is the ability for your installation to become an oEmbed provider. In plain English you can paste your post URL and get a result as if you were embedding a YouTube URL.
I could not get it to work for me. No way, no how. The json and XML discovery links were there in the post HTML but those links came back with “What? What? No. Go away, you’re bothering kid.”
It should have come back with a valid output and it did. It was a result, just not a functioning one.
For example, this post (which I’m not embedding) should provide via this link usable information. It doesn’t. I get this.
<link rel="alternate" type="application/json+oembed" href="https://blog.dembowski.net/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fblog.dembowski.net%2F2015%2Fserver-admins-love-wp-cli%2F" />
That link results in this.
{"code":"rest_missing_callback_param","message":"Missing parameter(s): url","data":{"status":400,"params":["url"]}}
It doesn’t contain any useful data except to reply with “What? What? What?”
It should output this.
{"version":"1.0","provider_name":"Mostly Harmless","provider_url":"https:\/\/blog.dembowski.net","author_name":"Jan Dembowski","author_url":"https:\/\/blog.dembowski.net\/author\/jan\/","title":"Server admins love WP-CLI","type":"rich","width":600,"height":338,"html":"</pre>
<blockquote class="\"wp-embedded-content\"">
<a href="\"https:\/\/blog.dembowski.net\/2015\/server-admins-love-wp-cli\/\"">Server admins love WP-CLI<\/a><\/blockquote>\n<script type="text\/javascript">// <![CDATA[
\n<!--\/\/--><![CDATA[\/\/><!--\n\t\t!function(a,b){\"use strict\";function c(){if(!e){e=!0;var a,c,d,f,g=-1!==navigator.appVersion.indexOf(\"MSIE 10\"),h=!!navigator.userAgent.match(\/Trident.*rv:11\\.\/),i=b.querySelectorAll(\"iframe.wp-embedded-content\"),j=b.querySelectorAll(\"blockquote.wp-embedded-content\");for(c=0;c<j.length;c++)j[c].style.display=\"none\";for(c=0;c<i.length;c++)if(d=i[c],d.style.display=\"\",!d.getAttribute(\"data-secret\")){if(f=Math.random().toString(36).substr(2,10),d.src+=\"#?secret=\"+f,d.setAttribute(\"data-secret\",f),g||h)a=d.cloneNode(!0),a.removeAttribute(\"security\"),d.parentNode.replaceChild(a,d)}else;}}var d=!1,e=!1;if(b.querySelector)if(a.addEventListener)d=!0;if(a.wp=a.wp||{},!a.wp.receiveEmbedMessage)if(a.wp.receiveEmbedMessage=function(c){var d=c.data;if(d.secret||d.message||d.value)if(!\/[^a-zA-Z0-9]\/.test(d.secret)){var e,f,g,h,i,j=b.querySelectorAll('iframe[data-secret=\"'+d.secret+'\"]'),k=b.querySelectorAll('blockquote[data-secret=\"'+d.secret+'\"]');for(e=0;e<k.length;e++)k[e].style.display=\"none\";for(e=0;e<j.length;e++)if(f=j[e],c.source===f.contentWindow){if(f.style.display=\"\",\"height\"===d.message){if(g=parseInt(d.value,10),g>1e3)g=1e3;else if(200>~~g)g=200;f.height=g}if(\"link\"===d.message)if(h=b.createElement(\"a\"),i=b.createElement(\"a\"),h.href=f.getAttribute(\"src\"),i.href=d.value,i.host===h.host)if(b.activeElement===f)a.top.location.href=d.value}else;}},d)a.addEventListener(\"message\",a.wp.receiveEmbedMessage,!1),b.addEventListener(\"DOMContentLoaded\",c,!1),a.addEventListener(\"load\",c,!1)}(window,document);\n\/\/--><!]]>\n<\/script><iframe sandbox=\"allow-scripts\" security=\"restricted\" src=\"https:\/\/blog.dembowski.net\/2015\/server-admins-love-wp-cli\/embed\/\" width=\"600\" height=\"338\" title=\"Embedded WordPress Post\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" class=\"wp-embedded-content\"><\/iframe>","thumbnail_url":"https:\/\/blog.dembowski.net\/wp-content\/uploads\/sites\/2\/2015\/12\/wp-cli-rocks.png","thumbnail_width":600,"thumbnail_height":135}
Which is unreadable to you and I but to something looking to oEmbed your post it will look like this.
Nice huh? All neat in an iframe and easily embeddable. The output is customizable too and I plan to do that on my photo blog.
The oEmbed discovery links should just work but on my installations it doesn’t. I tried Apache2, nginx, clean installation with zero plugins and the Twenty Fifteen theme. Different servers too. I always got the wrong output and could not get oEmbed working.
During my troubleshooting I found a different URL that worked consistently for me. It’s the same information but with a filter I replaced the default output with one that worked for me.
Here’s the plugin code I used. The oembed_discovery_links is filterable (filters are cool) and I toss out the old links and replace them with my own.
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| <?php | |
| /* | |
| Plugin Name: Fix oembed_discovery_links output | |
| Description: Modify the oembed discovery links in horrible ways | |
| Version: 1.0 | |
| Author: Jan Dembowski | |
| Author URI: https://blog.dembowski.net/ | |
| */ | |
| add_filter( 'oembed_discovery_links', 'mh_oembed_add_discovery_links' ); | |
| function mh_oembed_add_discovery_links( $output ) { | |
| $mh_newencoded = urlencode( home_url() . '/?p=' . get_the_ID() ); | |
| $output = '<link rel="alternate" type="application/json+oembed" href="' . esc_url( home_url() . '/?rest_route=%2Foembed%2F1.0%2Fembed&url=' . $mh_newencoded ) . '" />' . "\n"; | |
| if ( class_exists( 'SimpleXMLElement' ) ) { | |
| $output .= '<link rel="alternate" type="text/xml+oembed" href="' . esc_url( home_url() . '/?rest_route=%2Foembed%2F1.0%2Fembed&url=' . $mh_newencoded ) . '" />' . "\n"; | |
| } | |
| return $output; | |
| } |
This works for me but I do not like this solution.
The problem I have is that the normal links are not being replied to correctly via my WordPress installation. I don’t know why the default discovery links are not working. It bothers me, it really does. 😉
I’m convinced that there is something I’m doing wrong in my setup. Once I figure it out I’ll I can remove this plugin and I’ll post what I was missing.
