Add support for custom versions of mermaid (GH-9)

README.md

@@ -28,12 +28,21 @@ INSTALLED_APPS = [
 
 Once you have installed the app, you can use the `mermaid` template tag in your templates.
 
-```html
+```jinja2
 {% load mermaid %}
-
 {% mermaid "graph LR; A-->B;" %}
 ```
 
+By default, Django Mermaid uses the **9.4.3** version of mermaid. However, if you want to use a specific version of
+mermaid, you can set the `MERMAID_VERSION` variable in your Django project's settings.py file.
+
+```python
+MERMAID_VERSION = '10.0.3-alpha.1'
+```
+
+Make sure the version you specify is available on the [mermaid CDN](https://cdnjs.com/libraries/mermaid), and has
+the `mermaid.min.js` file.
+
 ## Contribute
 
 Any contribution is welcome. If you have any ideas or suggestions, feel free to open an issue or a pull request. And

src/django_mermaid/__init__.py

@@ -1 +1 @@
-__version__ = "0.0.2"
+__version__ = "0.0.3"

src/django_mermaid/apps.py

@@ -1,17 +1,24 @@
 from distutils import dir_util
-from os.path import dirname, join, exists
+from os import stat
+from os.path import dirname
+from os.path import exists
+from os.path import join
 from urllib.request import urlretrieve
 
 from django.apps import AppConfig
 
+from .templatetags import MERMAID_VERSION
+
 
 class MermaidConfig(AppConfig):
     name = "django_mermaid"
 
     def ready(self):
         """Download mermaid.js from CDN if not already present"""
-        cdn = "https://cdnjs.cloudflare.com/ajax/libs/mermaid/9.4.3/mermaid.js"
-        static = join(dirname(__file__), "static")
-        if not exists(join(static, "mermaid.js")):
-            dir_util.create_tree(static, ["mermaid.js"])
-            urlretrieve(cdn, join(static, "mermaid.js"))
+        cdn = "https://cdnjs.cloudflare.com/ajax/libs/mermaid/%s/mermaid.min.js" % MERMAID_VERSION
+        static_dir = join(dirname(__file__), "static")
+        mermaid_dir = join(static_dir, "mermaid", MERMAID_VERSION)
+        if not exists(join(mermaid_dir, "mermaid.js")) or \
+                stat(join(mermaid_dir, "mermaid.js")).st_size == 0:
+            dir_util.create_tree(mermaid_dir, ["mermaid.js"])
+            urlretrieve(cdn, join(mermaid_dir, "mermaid.js"))

src/django_mermaid/templatetags/__init__.py

@@ -0,0 +1,9 @@
+from django.conf import settings
+
+MERMAID_VERSION = getattr(
+    settings,
+    "MERMAID_VERSION",
+    "9.4.3",  # default to latest stable version
+)
+
+__all__ = ["MERMAID_VERSION"]

src/django_mermaid/templatetags/mermaid.py

@@ -2,6 +2,8 @@
 from django.templatetags.static import static
 from django.utils.safestring import mark_safe
 
+from . import MERMAID_VERSION
+
 register = template.Library()
 
 
@@ -14,5 +16,6 @@ def mermaid(diagram="", theme="default"):
     :param theme: The mermaid theme to use (default, forest, dark, neutral). See https://mermaid.js.org/config/theming.
     """
 
-    html = "<div class=\"mermaid\">%s</div><script src=\"%s\"></script>" % (diagram, static("mermaid.js"))
+    mermaid_uri = static("mermaid/%s/mermaid.js" % MERMAID_VERSION)
+    html = "<div class=\"mermaid\">%s</div><script src=\"%s\"></script>" % (diagram, mermaid_uri)
     return html + "<script>mermaid.initialize({\"startOnLoad\": true, theme: \"%s\"});</script>" % theme

tests/conftest.py

@@ -10,5 +10,6 @@ def pytest_configure():
             {
                 "BACKEND": "django.template.backends.django.DjangoTemplates",
             },
-        ]
+        ],
+        MERMAID_VERSION="8.6.3",  # Use a specific version of mermaid
     )

tests/test_tag.py

@@ -1,29 +1,39 @@
+from os.path import dirname
+from os.path import exists
+from os.path import join
+
 from django.template import Context
 from django.template import Template
 
+from django_mermaid.templatetags import MERMAID_VERSION
 from django_mermaid.templatetags.mermaid import mermaid
 
 
 def test_tag_renders():
     assert mermaid("graph LR; A-->B;") == (
-        """<div class="mermaid">graph LR; A-->B;</div><script src="mermaid.js"></script>"""
-        """<script>mermaid.initialize({"startOnLoad": true, theme: "default"});</script>"""
+            "<div class=\"mermaid\">graph LR; A-->B;</div><script src=\"mermaid/%s/mermaid.js\"></script>"
+            "<script>mermaid.initialize({\"startOnLoad\": true, theme: \"default\"});</script>" % MERMAID_VERSION
     )
 
 
 def test_tag_use_in_template():
     template = Template("{% load mermaid %}{% mermaid content %}")
     template = template.render(Context({"content": "graph LR; A-->B;"}))
     assert template == (
-        """<div class="mermaid">graph LR; A-->B;</div><script src="mermaid.js"></script>"""
-        """<script>mermaid.initialize({"startOnLoad": true, theme: "default"});</script>"""
+            "<div class=\"mermaid\">graph LR; A-->B;</div><script src=\"mermaid/%s/mermaid.js\"></script>"
+            "<script>mermaid.initialize({\"startOnLoad\": true, theme: \"default\"});</script>" % MERMAID_VERSION
     )
 
 
 def test_tag_use_in_template_with_arguments():
     template = Template("{% load mermaid %}{% mermaid content \"forest\" %}")
     template = template.render(Context({"content": "graph LR; A-->B;"}))
     assert template == (
-        """<div class="mermaid">graph LR; A-->B;</div><script src="mermaid.js"></script>"""
-        """<script>mermaid.initialize({"startOnLoad": true, theme: "forest"});</script>"""
+            "<div class=\"mermaid\">graph LR; A-->B;</div><script src=\"mermaid/%s/mermaid.js\"></script>"
+            "<script>mermaid.initialize({\"startOnLoad\": true, theme: \"forest\"});</script>" % MERMAID_VERSION
     )
+
+
+def test_tag_use_custom_version():
+    static_dir = join(dirname(__file__), "..", "src", "django_mermaid", "static")
+    assert exists(join(static_dir, "mermaid", MERMAID_VERSION, "mermaid.js"))