Check if asset files exist.

Author: Gordon Shotwell

shiny/examples/include_css/app.py

@@ -1,12 +1,12 @@
-import os
+from pathlib import Path
 
 from shiny import *
 
-css_file = os.path.join(os.path.dirname(__file__), "css/styles.css")
+css_file = Path(__file__).parent / "css" / "styles.css"
 
 app_ui = ui.page_fluid(
     "Almost before we knew it, we had left the ground!!!",
-    ui.include_css(css_file, method="link_files"),
+    ui.include_css(css_file),
     ui.div(
         # Style individual elements with an attribute dictionary.
         {"style": "font-weight: bold"},

shiny/examples/include_javascript/app.py

@@ -1,8 +1,8 @@
-import os
+from pathlib import Path
 
 from shiny import *
 
-js_file = os.path.join(os.path.dirname(__file__), "js/app.js")
+js_file = Path(__file__).parent / "js" / "app.js"
 
 app_ui = ui.page_fluid(
     "If you see this page before 'OK'-ing the alert box, something went wrong",

shiny/ui/_include_helpers.py

@@ -82,12 +82,13 @@ def include_js(
     ~ui.tags.script
     ~include_css
     """
+    file_path = check_path(path)
 
     if method == "inline":
-        return tags.script(read_utf8(path), **kwargs)
+        return tags.script(read_utf8(file_path), **kwargs)
 
     include_files = method == "link_files"
-    path_dest, hash = maybe_copy_files(path, include_files)
+    path_dest, hash = maybe_copy_files(file_path, include_files)
 
     dep, src = create_include_dependency("include-js-" + hash, path_dest, include_files)
 
@@ -159,11 +160,12 @@ def include_css(
     ~include_js
     """
 
+    file_path = check_path(path)
     if method == "inline":
-        return tags.style(read_utf8(path), type="text/css")
+        return tags.style(read_utf8(file_path), type="text/css")
 
     include_files = method == "link_files"
-    path_dest, hash = maybe_copy_files(path, include_files)
+    path_dest, hash = maybe_copy_files(file_path, include_files)
 
     dep, src = create_include_dependency(
         "include-css-" + hash, path_dest, include_files
@@ -177,6 +179,17 @@ def include_css(
 # ---------------------------------------------------------------------------
 
 
+def check_path(path: Path | str) -> Path:
+    path = Path(path)
+    if not path.exists():
+        err = f"""
+        {path.absolute()} does not exist.
+        Files are typically placed in the app directory and refered to with 'Path(__file__) / {path.name}'
+        """
+        raise RuntimeError(err)
+    return path
+
+
 def create_include_dependency(
     name: str, path: str, include_files: bool
 ) -> tuple[HTMLDependency, str]:
@@ -232,8 +245,8 @@ def get_hash(path: Path | str, include_files: bool) -> str:
 
 
 def get_file_key(path: Path | str) -> str:
-    path_str = str(path) if isinstance(path, Path) else path
-    return path_str + "-" + str(os.path.getmtime(path_str))
+    path = Path(path)
+    return str(path) + "-" + str(path.stat().st_mtime)
 
 
 def hash_deterministic(s: str) -> str: