applied-science.waqi — applied-science/waqi 0.0.1

Data visualizations from Clojure using Vega(-Lite) in the browser.

Waqi workflow is designed for the Clojurist who interacts with their data by iteratively visualizing (parts of) it, with code and resulting Vega-Embed simultaneously in view.

Users evaluate Vega/Vega-Lite specs (as Clojure maps) with plot! to see their data visualized in the browser. If Waqi has not started a server and established a WebSocket connection to a browser, it calls start-server! (with or without a port argument) to do so. If plot! cannot send a WebSocket message it will throw an error.

Architecture is as follows:

[bare-bones HTML page on localhost] ^ | (Vega(-Lite) specs, as JSON, sent via websocket) | v (Vega(-Lite) specs, [http-kit webserver] <--- as Clojure maps, ---- [client] sent via function call)

app clj

(app req)

HTTP request handler. Returns HTML page set up to receive Vega specs over WebSocket, unless the request is a WebSocket message to be sent to that page.

last-spec clj

JSON interpretation of most recent EDN Vega spec passed to Waqi.

loading-spec clj

Minimal Vega-Lite spec to show while loading user specs.

page clj

(page {:keys [port] :as opts})

HTML page to visualize Vega/Vega-Lite specs. Merely a skeleton with Vega and WebSocket connection to Vega-Embed.

page-js clj

(page-js port)

JavaScript snippet for the HTML page. Establishes a WebSocket connection to visualize incoming messages with Vega-Embed.

plot! clj

(plot! vega-spec)

(plot! port vega-spec)

Visualization fn. Sends the given EDN Vega spec to the browser to be visualized. Will start a Waqi server if none exists. Returns map of WebSocket response and Waqi config. Throws an error if WebSocket connection has been lost. Saves each spec to last-spec for debugging purposes.

Note that if the optional port is provided then any Waqi server running on another port will be stopped.

plot!* clj

(plot!* vega-spec)

ready-spec clj

Minimal Vega-Lite spec to show when page first loads.

server clj

Webserver: info & function to stop webserver.

start-server! clj

(start-server!)

(start-server! port)

Setup fn.

1. Starts Waqi webserver on given port or 8080 (stopping any existing Waqi webservers)
2. Opens HTML page in your browser to receive Vega specs
3. Returns map of current setup.

stop-server! clj

(stop-server!)

Tear-down fn. Stops Waqi webserver and nilifies related vars.

ws-chan clj

WebSocket channel for sending Vega specs to the browser.