[epic] Excel Viewer for Data Literate documents

[rufuspollock]

When I have an excel file (either remote or local) in a data literate document I want to be able to (pre)view it so that I get a sense of its content

Imagined use:

<ExcelViewer src="link-to-excel-file" />

This would render the excel file:

• A list of the sheets (bulleted list) - perhaps with some info e.g. number of active cells
• For each sheet a table preview
• BONUS: toggle to show hide (all) sheets

Other features

• Want to support both "local" and remote files
• Want to be able to reference remote files and have this just work ... => having a proxy to handle cors issues

Tasks

• [x] Working viewer app where you for (local) excel files using xlsx lib plus some basic rendering DONE: see https://data-literate.datopian.com/excel-viewer
• [x] Working viewer inline in markdown e.g. Excel src={url} using xlsx lib plus some basic rendering DONE: see https://data-literate.datopian.com/demo#display-excel-files
• [x] Get this working for remote files DONE. Using a local proxy API
• [ ] Make the presentation better e.g. show all sheets etc Showing a list of sheets but no switcher yet
  • [ ] Show list of sheets
  • [ ] Show each sheet
  • [ ] Hide all but first one and toggle display based on which sheet you click on

UX stuff

• [ ] show loading spinner whilst loading ...

Analysis

graph TD

excel[Excel file] -- xlsx lib --> wb[Workbook]
wb --> fd[Frictionless dataset]
fd -- dataset renderer --> render[Rendered Tables]

Remote support

Issue is that most data urls don't support cors ... so excel viewer does not work well (nor would other data viewers where i inline raw data urls ...)

Solutions

• Only allow for CORs hosted files
  • Excludes all stuff uploaded to github in issues etc
• Proxy
  • Con: now not pure static (unless proxy generic and outside this tool)
  • Con: could be abused (minor)
• Cache locally the data files ...
  • Con: have to download and cache all data files referenced in a markdown file ...