redisplay PHP form with errors - php

Question

I have a dozen fully functional scripts that use heredoc statements to display HTML including e.g. $errors[field_name] yet this nearly identical script results in POST errors like
"Notice: Undefined index: user_password in register.php on line 162"
When the user enters a password with 5 characters when 8+ characters are required, a validation function populates $errors['password'] and the form is supposed to re-display along with validation errors.
Can't see what I'm missing in this Bootstrap style form. The $errors array is global and I can force the display of errors, so I know errors are initialized but I keep getting
"Notice: Undefined index"
$fields = array( 'user_name', 'user_email', 'user_password', 'user_password2' );
function display_form($string = '')
{
global $error_token, $cfg, $fields, $form, $errors, $s, $token, $validation_status;
$error_message = '';
switch($_SERVER['REQUEST_METHOD'])
{
Case 'POST':
// validation failed, redisplay the form
$autofocus = '';
foreach($fields as $field){
$$field = htmlentities(get_cgi_var($field), ENT_QUOTES, 'UTF-8');
// wrap errors in Bootstrap alert markup
$errors[$field] = !empty($errors[$field]) ? '<div class="alert alert-danger">'.htmlentities($errors[$field], ENT_QUOTES, 'UTF-8').'</div>' : '';
// debug, force the premature display of errors.
// echo !empty($errors[$field]) ? '<div class="alert alert-danger">'.htmlentities($errors[$field], ENT_QUOTES, 'UTF-8').'</div>' : '<p>empty</p>';
}
break;
Case 'GET':
default:
$autofocus = 'autofocus';
foreach($fields as $field){
$$field = '';
$errors[$field] = '';
}
$error_token = '';
break;
};
foreach($fields as $field){
$validation_status[$field] = empty($errors[$field]) ? ' has-success' : ' has-error';
}
$self = SELF;
print<<<_HTML_
<div class="col-lg-6">
<div class="panel panel-primary">
<div class="panel-heading">Registration</div>
<div class="panel-body">
$string
$error_message
<form name="form1" id="form1" action="$self" class="form-horizontal" role="form" method="POST">
<fieldset>
$error_token
$errors[user_name]
<div class="row form-group$validation_status[user_name]">
<label for="user_name" class="col-lg-3 control-label">Name</label>
<div class="col-lg-9">
<input type="text" name="user_name" id="user_name" value="$user_name" maxlength="255" $autofocus required placeholder="Your First & Last Name" title="Your First & Last Name" autocomplete="on" class="form-control">
</div>
</div>
$errors[user_email]
<div class="row form-group$validation_status[user_email]">
<label for="user_email" class="col-lg-3 control-label">Email</label>
<div class="col-lg-9">
<input type="email" name="user_email" id="user_email" value="$user_email" maxlength="255" required placeholder="Your Email Address" autocomplete="on" class="form-control">
</div>
</div>
$errors[user_password]
<div class="row form-group$validation_status[user_password]">
<label for="user_password" class="col-lg-3 control-label">Password</label>
<div class="col-lg-9">
<input type="text" name="user_password" id="user_password" value="$user_password" maxlength="255" required placeholder="Password or Passphrase" autocomplete="on" class="form-control">
<p class="help-block">Case sensitive password containing 8+ characters or a phrase containing 3-5 words</p>
</div>
</div>
$errors[user_password2]
<div class="row form-group$validation_status[user_password2]">
<label for="user_password2" class="col-lg-3 control-label">Password</label>
<div class="col-lg-9">
<input type="text" name="user_password2" id="user_password2" value="$user_password2" maxlength="255" required placeholder="Re-enter Password or Passphrase" autocomplete="on" class="form-control">
</div>
</div>
<div class="row form-group">
<label for="submit_button" class="col-lg-3 control-label"> </label>
<div class="col-lg-9 text-center">
<input type="hidden" name="token" value="$token">
<input type="submit" name="submit_button" id="submit_button" value="Submit" onClick="return captcha_validation(this.form);" class="btn btn-primary">
</div>
</div>
</fieldset>
</form>
</div><!-- /panel-body -->
<div class="panel-footer text-center"> </div>
</div><!-- /panel -->
</div><!-- /col -->
<div class="col-lg-6">
<div class="well">unused column</div>
</div><!-- /col -->
_HTML_;
};

Answer 1

Here's your problem:
default:
$autofocus = 'autofocus';
foreach($fields as $field){
$$field = ''; // <------------------
$errors[$field] = '';
}
$error_token = '';
break;
replace $$field with $field or remove it altogether - it's not needed here.