3 · Signup form

signup.signup — signup.clj, signup_controller.clj.

State machine

stateDiagram-v2
  direction LR
  [*] --> editing : INIT / seed blanks
  editing --> submitted : SUBMIT [valid] / clear errors
  editing --> editing : SUBMIT / set errors
  submitted --> editing : RESET / blank memory
  submitted --> submitted : INIT

What to look at

• Inputs carry "data-bind" "signup1.name": typing writes the field into this component's slice of the store; no request per keystroke. The next event finds (:name memory) filled in.
• SUBMIT is a vector of options. The first has :cond valid? and a target; the second has no :cond and no target, so it stays in :editing and records :errors.
• When there are errors the render fn returns an effects list: [:patch (form ctx) {}] plus [:execute-script "…focus()"]. Any render may return hiccup or effects.
• :submitted handles :INIT {} — the re-INIT hatch every displayable state needs.
• A valid submit dissocs :errors; the pipeline sends it back as null so the client deletes the signal (the spec asserts :errors nil, not its absence).

Spec: block 3 in examples_test.clj.