Show blog post title in meta information - html

Question

I'm working on Search Engine Optimization for my Jekyll site, and I am running into an issue where I am unable to set meta information.
...
<meta name="og:title" content="{{ seo_title }}" />
...
<!-- now in my for post-loop: -->
{% for post in site.posts %}
<li class="post-link">
<a class="post-title" href="{{ post.url }}">
<span class="post-date">{{ post.date | date_to_string }}</span>
{{ assign seo_title = post.title }}
{{ post.title }}
</a>
</li>
{% endfor %}
I'm assigning sel_title to the post title, but it's not showing up in my meta information! I just get <meta name="og:title" content="" />
I've also tried adding {{ assign seo_title = page.title }} inside of my post.html post layout to no avail using {{ page.seo_title }} {{ post.seo_title }} and {{ seo_title }}
Now, obviously this really isn't what i want, because logically - after this for loop, it would set it to whatever the last post title was, but i can't even get that to display. Ideally what I would like, is for it to show up for the post.
You can view the page here where I want it to show up.
Where am I going wrong? How can I use my post information to fill my SEO meta information?

Answer 1

Had a look at your github repo. You are using only one basic layout for both index and posts. In your _posts, the YAML Front Matters is getting processed first time (and only once) when you do {% include post.html %}. But then you pass it on to the default layout and you cannot pass the YAML variables from the post through also.
One typical pattern you can adopt is split the default layout and create partial html files in the _includes folder i.e header.html and footer.html. You can then use them to create your default and post layouts. That way you can pass on the relevant YAML Front Matter variables in the post to the header.