fatfree framework, repopulate fields after unsuccessful validation - redirect

Question

I have GET route which shows the contact form, and POST route when user submits the form, then in my controller method I do some validation tests on data being submitted.. how would I now send user back to form if data is not valid, with entered data being re-populated in form fields?
I know I can use isset(#POST.fieldname) in my template, but what's the right way of
sending entered data back to that view, and how to redirect user back to the
form? Is the f3->reroute method right way of doing that?

Answer 1

I think you can take as a rule to include input data inside your form views. This way, any form view will be easily reusable with any source of data.
For example:
Your form view:
<form action="" method="post">
<input type="text" name="email" value="{{ ##input.email }}"/>
<input type="text" name="message" value="{{ ##input.message }}"/>
<button type="submit">Submit form</button>
</form>
Your controller class:
class myController {
function get($f3) {
$this->renderForm();
}
function post($f3) {
$post=$f3->clean($_POST);
//validate form data here
if ($form_validated) {//valid form data
} else //invalid form data
$this->renderForm($post);
}
protected function renderForm($input=array()) {
$tpl=Template::instance();
//variant 1:
echo $tpl->render('form.html','text/html',array('input'=>$input))
// or variant 2:
Base::instance()->set('input',$input);
echo $tpl->render('form.html');
}
}
In some other contexts, you can feed a form view with data coming from a db mapper (for example when editing an entry from a back-office): $this->renderForm($mapper->cast())