PHP: Hide Form after validation (class) - php

Question

I have a form that is mostly generated by a class named "buildform".
Now every part of the form validates itself on the position it is.
This looks like this:
echo $frm->create_input("customer_nr", "Customer Nr.", "text:empty:int");
The third attribute here are the conditions (here: text field, not empty only integer).
The function "create_input" calls some more function that are validating the form field directly on place when the form is submitted.
I do it this way for multiple reasons:
I can directly color the forms to red when there's an error
I only have to tell the form attributes one time instead of when creating it and validating.
This is really comfortable and until now has made creating forms very easy.
The validation errors for then the users will be stored in a class variable like this:
function add_err($n_errmsg) {
$this->errmsgs[] = $n_errmsg;
return;
}
At the end of the form I show the errors like this:
if(isset($_POST["sbm"])) {
$ret_err = $frm->ret_err();
if(!empty($ret_err)) {
echo $ret_err;
}
else {
// send success mail
}
}
This all works without any problems.
Now I had the idea to hide the form when it's submitted. But then I would have to make sure there are no errors before the form even is loaded!
I wanted to something like
else {
$hideform = true;
// send success mail
}
This currently is not possible as the errors are generated while "generating" the form fields.
If I move the errors to the top the errors are always "empty" there because the validation is done later below...
Do you have an idea how I can solve this?
Do I have to validate the forms before loading them or is there another way?
Thanks!
Best Regards
Toby

Answer 1

Ok, well there are a few ways to solve this.
Basically you are echoing the form html as you go along:
echo $frm->create_input(...);
echo $frm->create_input(...);
what you could do instead is save the html into a string:
$formhtml = '';
$formhtml .= $frm->create_input(...);
$formhtml .= $frm->create_input(...);
if($frm->ret_error()){
echo $formhtml;
//other logic
}else{
//send mail
}
Along the same lines, you could change your form class, so that this is done internaly, and add a show method:
private $html = '';
function create_input(...){
//retrun $ret;
$this->html .= $ret;
function show(){
echo $this->html;
}
$frm->create_input(...);
$frm->create_input(...);
if($frm->ret_error()){
$frm->show();
//other logic
}else{
//send mail
}