Jinja P5 Helper

This is where I defined some macros to add the p5 code to posts. It's based on the math_helper.tmpl template, although it took a little bit more work (well, too much work) to figure out how to get the metadata for this template.

{#  -*- coding: utf-8 -*- #}

<<p5-scripts-macro>>

<<p5-post-macro>>

<<p5-index-macro>>

This is the macro to call to add the tag to pull in the p5 code from a CDN.

{# macro to add the p5.js code tag #}
{% macro p5_scripts() %}
  <script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.6.0/p5.min.js"></script>
{% endmacro %}

This is a macro to use if you have a template with a single post object (e.g. if you override the post.tmpl template or one of its children). I'm using a dedicated template for p5 posts right now so it isn't being used.

{# macro for a single post #}
{# `post`: a Post object #}
{% macro p5_scripts_ifpost(post) %}
    {% if post.meta("has_p5") %}
	{{ p5_scripts() }}
    {% endif %}
{% endmacro %}

This is the macro I'm adding to the index.tmpl template to get p5 into the latest pages feed. Jinja doesn't support the comprehension-type syntax that mako does and Nikola puts the metadata dictionary into a Functionary object which is a default dict that is callable. The metadata dictionary that we want is actually set as the value to a key in the dictionary matching the language for the sight (en in my case). So you can't access it directly (e.g. you can't use post.meta.has_p5) but if you call the meta object like a function instead of using it as a dictionary it will bypass the language key for you so you don't have to know what the language is (e.g. post.meta("has_p5") is the same as post.meta.en.has_p5 (if English is the language being used)). Since I only use English it's probably unnecessary to use the function-syntax, but it seems to be the way it's intended to be used (and it took forever to figure out what was going on) so I'm using it.

But, after I set it up to check for has_p5 in the metadata I realized that this fixed the index.tmpl but I'd have to update the post.tmpl to use it for individual posts, which seemed like too much so I instead set it to also check if the post uses the p5.tmpl template. If I start adding more conditional imports maybe it'll make sense to use has_p5 but for now, the only way that works both in the feed and when viewing an individual post is to set the .. template: p5.tmpl metadata at the top of a post.

{# macro used by feed page with multiple posts (e.g. index.tmpl) #}
{# 'posts': list of Post objects #}
{# jinja doesn't support comprehensions so we have to use a for-loop #}
{# the ~post.meta~ object is a Functionary object #}
{# the metadata is in a dictionary that's in a dictionary #}
{# if you try ~post.meta.has_p5~ it will fail because you need the language you're using as a key #}
{# e.g. ~post.meta.en.has_p5~ #}
{# to not refer to the langugage you need to call it like a function, passing in the "has_p5" key as an argument #}
{% macro p5_scripts_ifposts(posts) %}
  {% set p5_added = False %}
  {% for post in posts %}
    {% if (post.meta("has_p5") or post.meta("template") == "p5.tmpl") and not p5_added %}
      {% set p5_added = True %}
      {{ p5_scripts() }}
    {% endif %}
  {% endfor %}
{% endmacro %}