I have a custom component where the user can add some data. Here are the two relevant fields:
<field
name="title"
type="text"
label="Title"
description="Please enter a title"
required="true"
/>
<field
name="alias"
type="text"
label="Alias"
description="Please enter an unique alias"
required="true"
/>
I am currently using the standard 'save' method to save the form data. But the problem obvious is that it is saving duplicate alias items. Where and how will I add a check to ensure that the alias is not in use (just like with Menu Item or Article).