How can I omit content from Octopress/Jekyll's extracted excerpt? - jekyll

Question

I'm using Octopress 2.0 for blogging, which uses the Jekyll static site generator.
To mark an excerpt of a blog post for the front page, you can insert <!--more--> into the post, and the content up to that point will be used as the excerpt..
For some posts, even though I want an excerpt, I want to exclude certain things from it (maybe a table of contents that only makes sense on the post, or some extra notes that aren't useful for an excerpt).
Is there a way in Octopress/Jekyll/Liquid to use the <!--more--> method to generate an excerpt, but also mark some small amount of content to be left out it?
Here is a brief example. Take this post:
---
layout: post
title: "Example Post"
---
This is the first paragraph. It will be included in the excerpt.
[Jump to third paragraph](#para3). This paragraph should **not** be in the excerpt.
This is the second paragraph. It will be included in the excerpt.
<!--more-->
<a name="para3"></a>This is the third paragraph. It won't be in the excerpt.
I want a way to have the generated excerpt for this post be:
This is the first paragraph. It will be included in the excerpt.
This is the second paragraph. It will be included in the excerpt.

Answer 1

Edit : I now understand what you're trying to do.
I assume that you're using the default octopress markdown : rdiscount.
Let's got the filter way :
In Gemfile add gem 'nokogiri'
In your post, the idea is to add a span.secondary to the part that has sometimes to be stripped. content
...
remove_secondary_content_from_excerpt : true
---
This is the first paragraph. It will be included in the excerpt.
[[Jump to third paragraph](#para3). This paragraph should **not**
be in the excerpt.](class:secondary)
This is the second paragraph. It will be included in the excerpt.
<!--more-->
### This is the TEXT title
This is **the text**
In _includes/article.html
...
</header>
{% endunless %}
{% if index %}
<div class="entry-content">
{% if post.remove_secondary_content_from_excerpt == true %}
{% capture secondary_content %}{{ post.excerpt | excerpt_get_secondary_content }}{% endcapture %}
{{ post.excerpt | remove: secondary_content }}
{% else %}
{{ post.excerpt }}
{% endif %}
</div>
{% capture excerpted %}{{ content | has_excerpt }}{% endcapture %}
{% if excerpted == 'true' %}
<footer>
<a rel="full-article" href="{{ root_url }}{{ post.url }}">{{ site.excerpt_link }}</a>
</footer>
{% endif %}
{% else %}
<div class="entry-content">
<!-- example on how to use it in post page -->
{% if page.remove_secondary_content_from_excerpt == true %}
{% capture secondary_content %}{{ page.excerpt | excerpt_get_secondary_content }}{% endcapture %}
{{ page.excerpt | remove: secondary_content }}
{{ secondary_content }}
{{ page.content | markdownify | remove: page.excerpt }}
{% else %}
{{ content }}
{% endif %}
</div>
{% endif %}
In _plugins/octopress_filters.rb
...
module OctopressLiquidFilters
def excerpt_get_secondary_content(input)
require 'nokogiri'
doc = Nokogiri::HTML(input)
# as excerpt can surrounded by one <p> (when no double newline in it)
# or with multiple <p> when a double newline is found
multiparagraph = doc.css("p").length > 1
if multiparagraph
# look for parent <p>
xpathString = "span.secondary/.."
end
# look only for the span element
xpathString = "span.secondary"
else
secondary = doc.css(xpathString)
secondary.to_s
end
...
Install Nokogiri bundle update
I hop your rake generate will make you happy.