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

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.