only include gist and codehilite css once if the code block (markdown) or raw html blocks have been used

Author: chris-lawton

tbx/core/templatetags/util_tags.py

@@ -3,6 +3,10 @@
 
 from tbx.core.utils.models import SocialMediaSettings
 
+from wagtail import blocks
+from wagtail.blocks import StreamValue
+from wagtailmarkdown.blocks import MarkdownBlock
+
 register = template.Library()
 
 
@@ -88,3 +92,17 @@ def ifinlist(value, list):
     # cast to strings before testing as this is used for heading levels 2, 3, 4 etc
     stringList = [str(x) for x in list]
     return str(value) in stringList
+
+
+@register.filter(name="has_raw_html_block")
+def has_raw_html_block(value):
+    if isinstance(value, StreamValue):
+        return any(type(item.block) is blocks.RawHTMLBlock for item in value)
+    return False
+
+
+@register.filter(name="has_markdown_block")
+def has_markdown_block(value):
+    if isinstance(value, StreamValue):
+        return any(type(item.block) is MarkdownBlock for item in value)
+    return False

tbx/project_styleguide/templates/patterns/molecules/streamfield/blocks/markdown_block.html

@@ -1,8 +1,6 @@
 {% load wagtailmarkdown static %}
 
 <div class="grid__markdown markdown-block">
-    <link rel="stylesheet" type="text/css" href="{% static 'css/codehilite.css' %}">
-
     {# tabindex needed because in order to scroll using the keyboard #}
     <div class="markdown-block__scroller" tabindex="0">
         {{ value|markdown }}

tbx/project_styleguide/templates/patterns/molecules/streamfield/blocks/raw_html_block.html

@@ -1,9 +1,5 @@
 {% load static %}
 
 <div class="grid__raw-html">
-    {% if 'gist' in value %}
-        <link rel="stylesheet" type="text/css" href="{% static 'css/gist.css' %}">
-    {% endif %}
-
     {{ value }}
 </div>

tbx/project_styleguide/templates/patterns/pages/blog/blog_detail.html

@@ -1,5 +1,16 @@
 {% extends "patterns/base_page.html" %}
-{% load wagtailcore_tags wagtailimages_tags static %}
+{% load wagtailcore_tags wagtailimages_tags util_tags static %}
+
+{% block extra_css %}
+    {{ block.super }}
+    {% if page.body|has_raw_html_block %}
+        <link rel="stylesheet" type="text/css" href="{% static 'css/gist.css' %}">
+    {% endif %}
+
+    {% if page.body|has_markdown_block %}
+        <link rel="stylesheet" type="text/css" href="{% static 'css/codehilite.css' %}">
+    {% endif %}
+{% endblock %}
 
 {% block meta_tags %}
     <script>