Voilà#

Voilà was developed by QuantStack.

Features#

  • Voilà supports interactive Jupyter widgets, including round trips to the kernel. Custom widgets like bqplot, ipyleaflet, ipyvolume, ipympl, ipysheet, plotly, ipywebrtc etc. are also supported.

  • Voilà does not allow arbitrary code execution by dashboard users.

  • Voilà is based on Jupyter standard protocols and file formats and works with any Jupyter-Kernel: C++, Python, Julia. This makes it a language-independent dashboard system.

  • Voilà is expandable. It contains a flexible Template system for creating extensive layouts.

Execution model#

digraph execution_model { graph [fontname = "Calibri", fontsize="12"]; node [fontname = "Calibri", fontsize="12"]; edge [fontname = "Consolas", fontsize="12"]; tooltip="Ausführungsmodell"; subgraph cluster_browser { notebook_url [ shape=box, label="Notebook url"; style=filled; fillcolor="#edf8fb"; color="#b2e2e2"]; html_rendering [ shape=box, label="HTML rendering"; style=filled; fillcolor="#edf8fb"; color="#b2e2e2"]; init_websocket [ shape=box, label="Javascript initiates Websocket\nwith the Jupyter kernel", style=filled; fillcolor="#edf8fb"; color="#b2e2e2"]; label="Browser"; labeljust="l"; } subgraph cluster_server { html_open_notebook [ shape=box, label="Open the notebook and start\nthe associated kernel"; style=filled; fillcolor="#bdd7e7"; color="#2171b5"]; html_run_notebook [ shape=box, label="Run notebook cells\nOutput results\nAssign Voilà template\nConvert notebook"; style=filled; fillcolor="#bdd7e7"; color="#2171b5"]; ws_open_notebook [ shape=box, label="Open the notebook and\nstart the associated kernel"; style=filled; fillcolor="#bdd7e7"; color="#2171b5"]; label="Server"; labeljust="l"; } // Edges notebook_url -> html_open_notebook [label="GET Request"] html_open_notebook -> html_run_notebook html_run_notebook -> html_rendering [label="HTTP Responses\lwith HTML or\lHTML fragments\l"] html_rendering -> init_websocket init_websocket -> ws_open_notebook [dir=both label="Web-Socket:\l- comm_msg\l- comm_info_request\l- kernel_info_request\l- shutdown_request\l"] // Arrangement {rank = same; notebook_url; html_rendering; init_websocket;} {rank = same; html_open_notebook; html_run_notebook; ws_open_notebook;} }

An important aspect of this execution model is that the frontend cannot specify which code is executed by the backend. Unless otherwise specified with the option --strip-sources=False, the source code of the rendered notebook does not even reach the frontend. The Voilà instance of jupyter_server does not allow execution requests by default.

Warning

The current version of Voilà does not respond to the first GET request until all cells have been executed. This can take longer. However, work is being done to enable progressive rendering, see feat: progressive cell rendering.

See also