Updating the UI in response to user value input and state changes in real time: error messaging, validation, presenting more relevant additional inputs, formatting, etc.
You have to do validation on the server anyway. Why do it again on the front end?
(:
Sorry, those turn up as 'must have' features in like, meeting #2 with the product owner, because the UI feels old and rubbish without them.
Technically? You're 100% right.
...but, I guarantee that even a LOB app, this will turn up, again and again and again as a feature request, until it becomes a tier 1 priority.
Did the user forget to fill a mandatory field? Is this phone number actually even possible? Does this zip/postal code exist? Is the age entered too low to create an account? Is the password long enough? Does it meet all the requirements. Can we dynamically show which requirements it doesn’t meet.
Even email, which you will want to verify by actually sending an email, can have some basic front end checks (is there an @ in the email entered by the user).
In fact, I bet the vast majority of validations can in fact be done in the front end in real time.
For simple projects, the validation built in to HTML form elements may be sufficient.
Yes you do.
Honestly, 99% of webapps today are 2 very interactive pages (which could often be developed in jQuery anyway) + bunch of generic datagrids & forms we have seen many times since the introduction of <form> and <table> tags decades ago.
Honestly, my problems as a developer generally aren't with the frameworks (I'm mostly defending Vue here, as I find it predictable and easy) but with the build tools, which have gotten a bit out of hand and always feel brittle.