The sample skin

A sample skin (skins/LoopData, registered as the report LoopDataReport) is included with the extension. After installing and restarting, and after waiting for a report cycle, it can be found at <weewx-url>/loopdata/. LoopData is initially configured with target_report = LoopDataReport, so the panel works out of the box on a fresh install.

The instrument panel

The page is a NOAA windrose plus eleven canvas gauges, drawn by a few hundred lines of dependency-free javascript — and every needle, petal and readout redraws on every loop packet:

• Temperature, dew point, feels-like and humidity dials wear today’s min–max as a band.
• The wind compass carries a second ghost needle at the 10-minute gust direction.
• The barometer draws the 3-hour trend as an arc, with a chevron showing the direction of travel.
• Rain and rain-rate dials rescale themselves on a big day.
• The windrose is the NOAA banded kind, drawn from day.windrose.banded and day.windrose.calm.
• UV, solar radiation and air quality (weewx-purple’s pm2_5_aqi) gauges — and the feels-like dial where appTemp is not computed — hide themselves when the station doesn’t report the observation, and reappear if the field shows up in loop-data.txt.

The division of labor is the loopdata pattern in miniature: the .raw fields drive the geometry, report-formatted fields supply the readouts, and unit.label fields pick the dial scales — so the panel follows the target report’s units and formatting (metric or US) like any other loopdata page. The gauges scale with the window: the engine draws in a 240-unit coordinate system stretched to the css size, so geometry and fonts grow together on a wide display (faces cap at 480px).

The fields line the panel reads is exactly the sample configuration’s fields line — fresh installs get it by default.

Upgrading from a pre-6.0 loopdata: upgrading replaces the sample skin’s page with the instrument panel but keeps your existing [LoopData] fields line, and the panel reads fields the old default never included (.raw geometry, unit.label scales, day.windrose.*). With an old fields line the page serves half-dead: text readouts but no needles, min–max bands or windrose. Replace the fields line with the sample configuration’s (append any fields other pages of yours use) and restart weewxd.

Translations

As of 6.4 the page is translatable through WeeWX lang files, and German ships (lang = de on the report’s stanza). Two languages meet on a loopdata page — the page’s labels follow this report’s lang, the live values follow the [LoopData] target report’s — see Translations for the mechanism and the coupling.

Skin options

In the skin’s [Extras] (see skins/LoopData/skin.conf):

• loop_data_file — the URL the page polls for the json file (default ../loop-data.txt, matching the default loop_data_dir = .).
• expiration_time — hours after which the page stops polling (so abandoned browser tabs don’t poll forever).
• page_update_pwd — loading the page as ?pageUpdate=<page_update_pwd> exempts it from expiration (for a kiosk display).

Files to crib from

• index.html.tmpl — element ids match the json keys, and Cheetah renders the report-time values so the page is populated before the first poll.
• realtime_updater.inc — the polling javascript: the fetch loop, the LIVE/OFFLINE/NO DATA/BAD DATA indicator, the expiration timer, and the canvas gauge and windrose rendering.

Building a live page walks through the same pattern for your own skin.