Add filename.ext as an option for download in views

lumen/tests/views/test_base.py

@@ -238,3 +238,32 @@ def test_view_title_download(set_root, view_type):
 
     button._on_click()
     assert button.data.startswith('data:text/plain;charset=UTF-8;base64')
+
+    assert view.download.filename is None
+    assert view.download.format == 'csv'
+
+
+@pytest.mark.parametrize("view_type", ("table", "hvplot"))
+def test_view_title_download_filename(set_root, view_type):
+    set_root(str(Path(__file__).parent.parent))
+    source = FileSource(tables={'test': 'sources/test.csv'})
+    view = {
+        'type': view_type,
+        'table': 'test',
+        'title': 'Test title',
+        'download': 'example.csv',
+    }
+
+    view = View.from_spec(view, source)
+
+    title = view.panel[0][0]
+    assert isinstance(title, pn.pane.HTML)
+
+    button = view.panel[0][1]
+    assert isinstance(button, DownloadButton)
+
+    button._on_click()
+    assert button.data.startswith('data:text/plain;charset=UTF-8;base64')
+
+    assert view.download.filename == 'example'
+    assert view.download.format == 'csv'

lumen/views/base.py

@@ -52,11 +52,10 @@ class Download(Component, Viewer):
     color = param.Color(default='grey', allow_None=True, doc="""
       The color of the download button.""")
 
-    filename = param.String(default=None, doc="""filenamefil
+    filename = param.String(default=None, doc="""
       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.
-      """)
+      If filename is not defined, it will be the name of the orignal table of the view.""")
 
     format = param.ObjectSelector(default=None, objects=DOWNLOAD_FORMATS, doc="""
       The format to download the data in.""")
@@ -109,10 +108,7 @@ def _table_data(self) -> IO:
         return io
 
     def __panel__(self) -> DownloadButton:
-        if self.filename:
-            filename = self.filename
-        else:
-            filename = slugify(self.view.title or self.view.pipeline.table)
+        filename = self.filename or slugify(self.view.pipeline.table)
         filename = f'{filename}.{self.format}'
         return DownloadButton(
             callback=self._table_data, filename=filename, color=self.color,
@@ -189,7 +185,9 @@ def __init__(self, **params):
         if pipeline is None:
             raise ValueError("Views must declare a Pipeline.")
         if isinstance(params.get("download"), str):
-            params["download"] = Download(format=params["download"])
+            *filenames, ext = params.get("download").split(".")
+            filename = ".".join(filenames) or None
+            params["download"] = Download(filename=filename, format=ext)
         fields = list(pipeline.schema)
         for fp in self._field_params:
             if isinstance(self.param[fp], param.Selector):
@@ -385,7 +383,9 @@ def from_spec(
         # Resolve download options
         download_spec = spec.pop('download', {})
         if isinstance(download_spec, str):
-            download_spec = {'format': download_spec}
+            *filenames, ext = download_spec.split('.')
+            filename = '.'.join(filenames) or None
+            download_spec = {'filename': filename, 'format': ext}
         resolved_spec['download'] = Download.from_spec(download_spec)
 
         view = view_type(refs=refs, **resolved_spec)