I'm writing a custom page template and I want to do something like this: after typing tag inside page content, for example [custom-email-form] I want to place inside the content some html5 email form.
How to achieve that?
Thanks.
Do you mean that when the page is rendered your [custom-email-form]
is replaced with html? That's just a custom shortcode. Just create a plug-in that registers the shortcode and then outputs its content when called.