Form

Jan @Novoj Novotný

Go through presentation with me
https://goo.gl/KznAa9

Solved problem in 2018?

You don't see this too much lately:

Why we need form validations?

help the user to fill the data correctly

Why we need form validations?

protect application from consuming bad input

Why do we still fail in 2018?

1. error handling doesn't lie on happy path
2. it's considered "someone else's problem"
3. even customers often don't have checking those
   in acceptation protocols

What are best practices of validation?

Right time right after the user completed the input Right place next to the field where the problem is Right color red is for errors, blue for information, yellow for warnings, green for the confirmation of success Clear language what happened, what can user do about it Accept partially correct data correct them yourself when you can Never rely on client side validations or you'd be surprised soon

What choices did we made in FG Forrest?

Single place of truth

same logic executes validation on client and on server
some validations also can't be executed on client (free account)

Inline/live validation

user gets feedback immediately

Form state is kept on server

client sends only incremental diffs in user entered data

No programming required

developer should not be bothered by tuning validations

Showtime

Ordinary form

Registration form

Corner cases

related fields user devices with limited space enumeration attacks race conditions session drops conditional blocks of forms