How do I share an ECharts chart as a link?

Vendor `echarts.min.js` next to your HTML, reference it relatively, then drag both files into Comma. The script uploads as an asset with its reference rewritten, so the chart renders without depending on a CDN.

Why is my published ECharts page blank?

Almost always a CDN script that did not load. Charts built by pyecharts and similar tools default to a remote `echarts.min.js`; download it, put it beside the HTML, and change the ` ` to the relative filename.

How do I make pyecharts emit a local script reference?

Point its asset host at a local path — `CurrentConfig.ONLINE_HOST = "./"` before rendering — so the generated HTML references `echarts.min.js` relatively instead of a CDN URL. Ship that file alongside the output.

Does zoom, tooltip and legend filtering still work?

Yes. Report HTML renders with scripts enabled inside a sandboxed iframe, so dataZoom, tooltips, legend toggling and the toolbox all behave.

Can I refresh the chart on a schedule?

Yes — regenerate and PATCH the same report id, or use a routine. One stable URL, a revision per refresh.

Share an ECharts HTML file

ECharts produces some of the best interactive charts on the web, and an exported ECharts page has one dependency that ruins it in transit: a <script src="https://cdn…/echarts.min.js"> tag.

Send that file to someone on a locked-down network, or open it anywhere the CDN is unreachable, and you get a blank div. The chart data is right there in the file; the renderer never arrives.

Vendor the library

Download it once and reference it relatively:

curl -fsSLO https://cdn.jsdelivr.net/npm/echarts/dist/echarts.min.js

<script src="echarts.min.js"></script>

From pyecharts, point the asset host at a local path before rendering so the generated HTML does the same:

from pyecharts.globals import CurrentConfig
CurrentConfig.ONLINE_HOST = "./"          # emit ./echarts.min.js, not a CDN URL

chart.render("chart.html")

Then copy echarts.min.js next to chart.html.

Publish both files

Drag chart.html and echarts.min.js together into the app:

chart.html becomes the report body.
echarts.min.js uploads as an asset and the <script src> reference is rewritten to the uploaded copy — the step that makes the chart independent of any CDN.
Scripts run inside a sandboxed iframe (allow-scripts, no allow-same-origin), so dataZoom, tooltips, legend filtering and the toolbox export all work.

The recipient gets a working chart, not a blank rectangle and a request to "try a different browser".

Refresh it

python build_chart.py      # → chart.html

curl -fsS -X PATCH "https://commareports.com/api/v1/reports/$REPORT_ID" \
  -H "Authorization: Bearer $COMMA_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --rawfile html chart.html \
        --arg title "Traffic — $(date +%Y-%m-%d)" '{title: $title, html: $html}')"

The vendored script stays attached to the report, so subsequent refreshes only need to replace the entry HTML. A routine can run the whole thing on a cadence.

What review adds

Anchored threads on the chart — the question about the spike attached to the spike. See commenting on HTML.
Revisions, so week-over-week comparison does not depend on someone having kept the old screenshot.

Limits

Entry HTML: 5 MB. A chart with a large inlined dataset is the case that gets close — downsample, or move the series into a JSON asset.
Assets: 25 MB per file, 250 MB and 500 files total.
60 requests/minute per token.

Try it

Comma is free — unlimited reports, unlimited commenters, unlimited revision history.

Publish a chart →