Warn about bad jQuery selectors

ltk/jquery.py

@@ -28,13 +28,43 @@ class MonkeyPatchedTimeModuleForMicroPython:
 
 
 jQuery = window.jQuery
-find = jQuery
-create = jQuery
 parse_int = window.parseInt
 parse_float = window.parseFloat
 local_storage = window.localStorage
 timers = {}
 
+
+def find(selector):
+    is_element = not isinstance(selector, str)
+    is_body = selector == "body"
+    is_selector = isinstance(selector, str) and (selector.startswith(".") or selector.startswith("#"))
+    is_html = isinstance(selector, str) and selector.startswith("<")
+    if not is_element and not is_body and not is_selector:
+        try:
+            error = f"A jQuery selector should start with '.' or '#', not '{selector}'"
+            if is_html:
+                error += ". To generate HTML, use ltk.create(...)"
+            print(f"Error: {error}")
+            import traceback
+            traceback.print_stack()
+        except:
+            pass
+    return jQuery(selector)
+
+
+def create(html):
+    html = html.strip()
+    if not html or html[0] != "<":
+        try:
+            error = f"A jQuery html fragment should start with '<', not '{html}'"
+            print(f"Error: {error}")
+            import traceback
+            traceback.print_stack()
+        except:
+            pass
+    return jQuery(html)
+
+
 KB = 1024
 MB = KB * KB
 GB = MB * MB

ltk/logger.py

@@ -13,6 +13,7 @@ class Logger(ltk.Div):
     classes = [ "ltk-log-list" ]
     level = logging.INFO
     messages = []
+    callback_count = 0
     icons = { 
         logging.CRITICAL : '💥',
         logging.ERROR    : '🔥️',
@@ -123,6 +124,9 @@ def _add(self, level, *args, **argv):
         try:
             message = " ".join(map(str, args))
             if message.startswith("js_callable_proxy"):
+                self.callback_count += 1
+                if self.callback_count % 1000 == 0:
+                    print(f"{self.callback_count} Python functions called by jQuery: {message}")
                 return
             self.messages.append(message)
             ltk.find(".ltk-log-header").after(

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pyscript-ltk"
-version = "0.1.28"
+version = "0.1.29"
 description = "A little toolkit for writing UIs in PyScript"
 readme = "README.md"
 authors = [{ name = "Chris Laffra", email = "chris@chrislaffra.com" }]