Improve Download with Index and Filename parameters

lumen/util.py

@@ -5,6 +5,7 @@
 import os
 import re
 import sys
+import unicodedata
 
 from functools import wraps
 from logging import getLogger
@@ -314,3 +315,25 @@ def wrapper(*args, **kwargs):
         return decorator(function)
 
     return decorator
+
+
+def slugify(value, allow_unicode=False) -> str:
+    """
+    Convert to ASCII if 'allow_unicode' is False. Convert spaces or repeated
+    dashes to single dashes. Remove characters that aren't alphanumerics,
+    underscores, or hyphens. Convert to lowercase. Also strip leading and
+    trailing whitespace, dashes, and underscores.
+
+    From: https://docs.djangoproject.com/en/4.0/_modules/django/utils/text/#slugify
+    """
+    value = str(value)
+    if allow_unicode:
+        value = unicodedata.normalize("NFKC", value)
+    else:
+        value = (
+            unicodedata.normalize("NFKD", value)
+            .encode("ascii", "ignore")
+            .decode("ascii")
+        )
+    value = re.sub(r"[^\w\s-]", "", value.lower())
+    return re.sub(r"[-\s]+", "-", value).strip("-_")

lumen/views/base.py

@@ -33,7 +33,7 @@
 from ..transforms.base import Transform
 from ..transforms.sql import SQLTransform
 from ..util import (
-    VARIABLE_RE, catch_and_notify, is_ref, resolve_module_reference,
+    VARIABLE_RE, catch_and_notify, is_ref, resolve_module_reference, slugify,
 )
 from ..validation import ValidationError
 
@@ -52,12 +52,21 @@ class Download(Component, Viewer):
     color = param.Color(default='grey', allow_None=True, doc="""
       The color of the download button.""")
 
-    hide = param.Boolean(default=False, doc="""
-      Whether the download button hides when not in focus.""")
+    filename = param.String(default=None, doc="""filenamefil
+      The filename of the downloaded table.
+      File extension is added automatic based on the format.
+      If filename is not added, it will be based on the name of the view.
+      """)
 
     format = param.ObjectSelector(default=None, objects=DOWNLOAD_FORMATS, doc="""
       The format to download the data in.""")
 
+    hide = param.Boolean(default=False, doc="""
+      Whether the download button hides when not in focus.""")
+
+    index = param.Boolean(default=True, doc="""
+      Whether the downloaded table has an index.""")
+
     kwargs = param.Dict(default={}, doc="""
       Keyword arguments passed to the serialization function, e.g.
       data.to_csv(file_obj, **kwargs).""")
@@ -89,18 +98,22 @@ def _table_data(self) -> IO:
             io = BytesIO()
         data = self.view.get_data()
         if self.format == 'csv':
-            data.to_csv(io, **self.kwargs)
+            data.to_csv(io, index=self.index, **self.kwargs)
         elif self.format == 'json':
-            data.to_json(io, **self.kwargs)
+            data.to_json(io, index=self.index, **self.kwargs)
         elif self.format == 'xlsx':
-            data.to_excel(io, **self.kwargs)
+            data.to_excel(io, index=self.index, **self.kwargs)
         elif self.format == 'parquet':
-            data.to_parquet(io, **self.kwargs)
+            data.to_parquet(io, index=self.index, **self.kwargs)
         io.seek(0)
         return io
 
     def __panel__(self) -> DownloadButton:
-        filename = f'{self.view.pipeline.table}.{self.format}'
+        if self.filename:
+            filename = self.filename
+        else:
+            filename = slugify(self.view.title or self.view.pipeline.table)
+        filename = f'{filename}.{self.format}'
         return DownloadButton(
             callback=self._table_data, filename=filename, color=self.color,
             size=18, hide=self.hide

setup.py

@@ -31,6 +31,7 @@ def get_setup_version(reponame):
     'sql': [
         'duckdb',
         'intake-sql',
+        'sqlalchemy <2',  # Don't work with pandas yet
     ],
     'tests': [
         'pytest',