Suppress flow start page

[RachelBrodsky]

When entering a flow, there is a start page prompting the user to start a new session or re-enter an existing session. We would like to add functionality to bypass this start page and immediately start a flow session.

Is it possible to suppress the start page?

[inducer]

Currently, in order for anyone to view a flow, they need to have a FlowSession. If they get a randomized version of the flow, then this records their randomization and is also used as an anchor point to store their page views and responses. The main purpose of the start page is to generate a POST request to facilitate the creation of the FlowSession.

There are a few possible avenues for suppressing start pages:

• Use Javascript to automatically generate a POST request. Kind of yucky, might not work for users who have JS turned off.
• Create the session in a GET request. This isn't great for most types of flows, where HTTP caching semantics could lead to redundant session creation, but I think for "unimportant"/non-graded flows, I'd be willing to tolerate it.
• Have all participants use the same flow session (kind of yucky)
• Avoid creating flow sessions altogether (sounds like it could be invasive in terms of internal logic... not sure)

The other question is: for which types of flows should the start page be suppressed? A few options:

• Ones that have empty start page description
• Ones that have only non-interactive pages
• Ones that explicitly say so via a flag.
• Ones that do not generate a grade
• All/a subset of the above?