Arvados

Note that at least one pipeline author has written Crunch scripts that expect exactly these "JSON strings" and reads them in with json.loads(). Part of the reason for that is Workbench doesn't have any support for input arrays or objects either, so letting pipeline users simply write the JSON by hand in a string is actually the most straightforward solution right now.

Proposed implementation: if your input starts with ", [, or {, it's assumed to be JSON, parsed as such, and then the resulting value is stored as the value of the corresponding parameter.

This potentially breaks compatibility for existing callers of a-r-p-i, but we think we can live with it since it's easy enough to work around: just double-quote (and potentially escape) your string.

Why not add in a flag so old behavior stays the same while still giving the user the option for more complex parameter passing? Something like:

arv-run-pipeline-instance --json-param 'foo::input={"foo":"bar"}'

...or even

arv-run-pipeline-instance --param 'foo::input={"foo":"bar"}'

?