Make themes list depend on installed themes

README.rst

@@ -242,7 +242,9 @@ How to customize the look:
     * `list of daisyUI color names`_
     * `Tailwind CSS theme customization`_
 
-*  Override the default main stylesheet path by providing a ``path_to_stylesheet`` value in a template ``context``.
+*  Override the default main stylesheet path by setting ``STYLESHEET_PATH`` in
+   the environment. The path is under ``STATIC_URL``. This depends on the
+   context processor ``argus_htmx.context_processors.path_to_stylesheet``.
 *  Include additional styles/stylesheets using the ``head`` block in your templates.
 *  Generate a Tailwind config file by running the ``tailwind_config`` management
    command. By default the generated file will be based on

src/argus_htmx/appconfig.py

@@ -25,6 +25,7 @@
         },
         "context_processors": [
             "argus.auth.context_processors.preferences",
+            "argus_htmx.context_processors.path_to_stylesheet",
         ],
         "middleware": {
             "argus_htmx.middleware.LoginRequiredMiddleware": "end",

src/argus_htmx/apps.py

@@ -1,4 +1,5 @@
 import pathlib
+
 from django.apps import AppConfig
 
 
@@ -9,3 +10,7 @@ class HtmxFrontendConfig(AppConfig):
 
     def tailwind_css_files(self):
         yield from pathlib.Path(__file__).parent.glob("tailwindtheme/snippets/*.css")
+
+    def ready(self):
+        # Register checks
+        from .checks import check_for_valid_themes_list  # noqa: F401

src/argus_htmx/checks.py

@@ -0,0 +1,30 @@
+from django.core.checks import Error, register
+from django.core.exceptions import ImproperlyConfigured
+
+from .themes.utils import get_theme_names
+
+
+@register
+def check_for_valid_themes_list(app_configs, **kwargs):
+    errors = []
+    themes = []
+    try:
+        themes = get_theme_names()
+    except ImproperlyConfigured as e:
+        errors.append(
+            Error(
+                str(e),
+                hint="Regenerate styles.css",
+                id="argus_htmx.T001",
+            )
+        )
+    else:
+        if not themes:
+            errors.append(
+                Error(
+                    "no themes installed",
+                    hint='Check the settings "DAISYUI_THEMES" and "TAILWIND_THEME_OVERRIDE" and regenerate styles.css',
+                    id="argus_htmx.T002",
+                )
+            )
+    return errors

src/argus_htmx/context_processors.py

@@ -7,12 +7,8 @@
 See django settings for ``TEMPLATES``.
 """
 
-from argus.auth.models import Preferences
+from .settings import STYLESHEET_PATH
 
 
-def preferences(request):
-    pref_sets = Preferences.objects.filter(user=request.user)
-    prefdict = {}
-    for pref_set in pref_sets:
-        prefdict[pref_set._namespace] = pref_set.get_context()
-    return {"preferences": prefdict}
+def path_to_stylesheet(request):
+    return {"path_to_stylesheet": STYLESHEET_PATH}

src/argus_htmx/settings.py

@@ -25,6 +25,7 @@
 TAILWIND_CONFIG_TARGET = "src/argus_htmx/tailwindtheme/tailwind.config.js"
 TAILWIND_CSS_TARGET = "src/argus_htmx/tailwindtheme/styles.css"
 
+STYLESHEET_PATH_DEFAULT = "styles.css"
 DEFAULT_THEMES = [
     "dark",
     "light",
@@ -57,3 +58,4 @@
 THEME_DEFAULT = get_str_env("ARGUS_THEME_DEFAULT", "argus")
 DEFAULT_THEME_OVERRIDE = {}
 TAILWIND_THEME_OVERRIDE = get_json_env("TAILWIND_THEME_OVERRIDE", DEFAULT_THEME_OVERRIDE, quiet=True)
+STYLESHEET_PATH = get_str_env("STYLESHEET_PATH", STYLESHEET_PATH_DEFAULT)

src/argus_htmx/themes/utils.py

@@ -1,21 +1,50 @@
+from importlib.resources import files
+from pathlib import Path
+
 from django.conf import settings
-from argus_htmx import settings as argus_htmx_settings
+from django.core.exceptions import ImproperlyConfigured
 
+from argus_htmx import settings as default_htmx_settings
 
-def get_themes():
-    return getattr(settings, "DAISYUI_THEMES", argus_htmx_settings.DAISYUI_THEMES)
 
+__all__ = ["get_theme_names"]
 
-def get_theme_names():
-    themes = get_themes()
+
+def get_themes_from_setting():
+    themes_setting = getattr(settings, "DAISYUI_THEMES", default_htmx_settings.DAISYUI_THEMES)
     theme_names = []
-    for theme in themes:
+    for theme in themes_setting:
         if isinstance(theme, str):
             theme_names.append(theme)
         elif isinstance(theme, dict):
             theme_names.extend(theme.keys())
     return theme_names
 
 
+def get_themes_from_css():
+    static_url = Path(settings.STATIC_URL).relative_to("/")
+    stylesheet_path = static_url / default_htmx_settings.STYLESHEET_PATH
+    styles_css = files("argus_htmx").joinpath(stylesheet_path).read_text()
+    styles_css_lines = styles_css.split("{")
+    theme_names = []
+    for line in styles_css_lines:
+        if "data-theme=" not in line:
+            continue
+        _, after = line.split("=", 1)
+        theme_name, _ = after.split("]", 1)
+        theme_names.append(theme_name.strip())
+    return theme_names
+
+
+def get_theme_names():
+    themes_from_setting = set(get_themes_from_setting())
+    themes_from_css = set(get_themes_from_css())
+    installed_themes = themes_from_setting | themes_from_css
+    all_themes = themes_from_setting & themes_from_css
+    if all_themes != installed_themes:
+        raise ImproperlyConfigured("Themes in settings is out of sync with themes installed")
+    return installed_themes
+
+
 def get_theme_default():
-    return getattr(settings, "THEME_DEFAULT", argus_htmx_settings.THEME_DEFAULT)
+    return getattr(settings, "THEME_DEFAULT", default_htmx_settings.THEME_DEFAULT)