Handle storage for document attachments

[ethangardner]

Overview

As a form editor, I would like be able to view the documents that the user uploaded, so that I can see all relevant information.

Context

During our form builder epic, we added the attachment component and made the decision to revisit how we're storing attachments when the requirements were more clear. We need to put some definition around how the document is stored in the following ways:

• SSR version (e.g. blob in the DB, cloud storage, something else?)
• SPA version (File object, data uri in local storage, something else?)

We also need to put some definition around how uploaded documents should be passed around on the session.

Acceptance Criteria

• We have a storage option that works for SSR and SPA
• We can accommodate storage on the session when there may be multiple MB attached to the form.

Definition of done

The "definition of done" ensures our quality standards are met with each bit of user-facing behavior we add. Everything that can be done incrementally should be done incrementally, while the context and details are fresh. If it’s inefficient or “hard” to do so, the team should figure out why and add OPEX/DEVEX backlog items to make it easier and more efficient.

• Behavior
  • Acceptance criteria met
  • Implementation matches design decisions
• Documentation
  • ADRs (/documents/adr folder)
  • Relevant README.md(s)
• Code quality
  • Code refactored for clarity and no design/technical debt
  • Adhere to separation of concerns; code is not tightly coupled, especially to 3rd party dependencies; dependency rule followed
  • Code is reviewed by team member
  • Code quality checks passed
• Security and privacy
  • Automated security and privacy gates passed
• Testing tasks completed
  • Automated tests pass
  • Unit test coverage of our code >= 90%
• Build and deploy
  • Build process updated
  • API(s) are versioned
  • Feature toggles created and/or deleted. Document the feature toggle
  • Source code is merged to the main branch

Decisions

• Optional: Any decisions we've made while working on this story