Trouble inserting text from a PHP text field into an other PHP function

Question

I'm working with a custom autonav in the Concrete5 CMS - but I think this might be more of a general PHP question. I'm having a hard time figuring out if it is possible to do the following.

I have some autonav code that looks like this:

<?php   defined('C5_EXECUTE') or die("Access Denied."); ?>
<?php
$nav = BlockType::getByHandle('autonav');
$nav->controller->orderBy = 'display_asc';
$nav->controller->displayPages = 'custom';
$nav->controller->displayPagesCID = '135';
$nav->controller->displaySubPages = 'all';
$nav->controller->displaySubPageLevels = 'all';
$nav->render('tertiary');
?>

I also have a text field that outputs via the following code:

<?php  if (!empty($field_4_textbox_text)): ?>
    <?php  echo htmlentities($field_4_textbox_text, ENT_QUOTES, APP_CHARSET); ?>
<?php  endif; ?>

What I'd like to do is have the text output within this line of the autonav code:

$nav->controller->displayPagesCID = '135';

Instead of the hard coded 135, I'd like the text outputted by $field_4_textbox_text to display within those single quotes. Something like:

$nav->controller->displayPagesCID = 'echo $field_4_textbox_text';

But that doesn't work. Nothing I've done works. Is there something obvious I might be missing? I'm feeling clueless.

Thanks!

Answer 1

Use double quotes to parse variables, single quotes can never parse variables in php

$nav->controller->displayPagesCID = " $field_4_textbox_text";