Ability to consume attachment in CSV format within the form

[ebruchez]

Scenario:

• attach CSV file
• action reads CSV file and populates a repeated grid with the contents of the file

What we already have:

• an Attachment form control, of course
  • the result in the form is a URL (pointing either to a temporary file, or to a persistence layer URL)
• the Action Syntax,
  • allows calling services, iterating over data, filling grids, setting control values
• calling an action upon a file being attached
  • fr:attachment dispatches xforms-value-changed, and might be good enough
  • it could also dispatch xforms-select/xforms-deselect

What is needed:

• calling a service or function which can dereference the URL of an attachment
  • services currently are not linked to attachments
  • possibly the doc() function could be used?
  • XPath 3 has unparsed-text(), which is a better fit
• convert CSV content to XML
  • we do this for JSON already (XForms 2) in submissions and with xxf:json-to-xml()
  • XForms 2 also specifies a conversion for CSV, which we could implement as xxf:csv-to-xml()
    • Add new xxf:csv-to-xml() and xxf:xml-to-csv() functions #6826

Security considerations:

• consider what URLs doc() and/or unparsed-text() have access to

+1 from customer

[avernet]

It might also be worth thinking about what a higher-level solution built into Form Runner would look like. For example, form authors could enable an "Add CSV/Excel data" feature for any repeated grid that could implement that functionality, possibly mapping columns in the CSV/Excel to columns in the grid. We could have options for replace versus add. The CSV/Excel wouldn't be attached to the form.

[ebruchez]

Higher-level has benefits:

• more form author-friendly
• can be maintained and improved over time

Drawbacks:

• larger implementation effort

The two approaches are not exclusive.