Add Error Feedback

[LeStarch]

We need to add error feedback to the form that attendees use to add tickets see (https://lestarch.github.io/repair-cafe-app). Specifically, if a required field is omitted or an email address is not of the form (something@something.something).

This is typically done by adding a hidden div for each input that uses a alert-danger bootstrap class. This should contain a v-show attribute to render it only when there is an error. The error data should be bound to a custom validation function which sets a solid error.

Something similar is done to report success:

repair-cafe-app/src/views/repairs/update.template.js

Lines 47 to 49 in 4fbbffb

	<div v-if='last_id !== "" && editing.name === "" && editing.type === ""' class="row alert alert-success">
	<h4>Request Submitted: Please proceed to check-in to receive your ticket!</h4>
	</div>