Using php inside javascript in wordpress - php

Question

I have got the following code in a javascript(jquery) file called custom.js:
blabla = new Date(2014, 06 - 1, 2);
$('.days').countdown({
until: blabla,
layout: '{dn} {dl}',
1.Now i want a user to be able to change the above date. I have created a theme options page called theme-options.php
2.I am using <?php require_once('theme-options.php'); ?> in the functions.php to link to theme-options.php.
3.This is theme-options.php:
<?php
add_action('admin_menu', 'director_create_menu');
function director_create_menu() {
add_submenu_page( 'themes.php', ' Theme Options',
'Theme Options', 'administrator', __FILE__,
'director_settings_page');
add_action( 'admin_init', 'director_register_settings' );
}
function director_register_settings() {
register_setting( 'director-settings-group', 'director_date' );
}
div class="wrap">
<h2>Theme Settings</h2>
<form id="landingOptions" method="post" action="options.php">
<?php settings_fields( 'director-settings-group' ); ?>
<table class="form-table">
<tr valign="top">
<th scope="row">Date:</th>
<td>
<input type="text" placeholder="2014, 06 - 1, 2" name="director_date"
value="<?php print get_option('director_date');
?>" />
</td>
</tr>
<p class="submit">
<input type="submit" class="button-primary" value="<?php _e('Save Changes') ?>" />
</p>
</form>
</div>
<?php } ?>
Basically what is happening is that there is a theme options page.A user gives a date inside it. Now i want to use that date inside the javascript file.
If I had to use it inside index.php it would've been
<?php $date = get_option('director_date'); ?>
<?php if( $date ) : ?> <?php echo $date; ?><?php endif; ?>);
. However this is javascript. How do i implement such an action here?
An alternative path but still doesn't work.Rename custom.js to custom.php and add:
gapinvite = new Date(<?php $date = get_option('director_date'); ?>
<?php if( $date ) : ?> <?php echo $date; ?><?php endif; ?>);
$('.days').countdown({
until: gapinvite,
layout: '{dn} {dl}',
And in functions.php:
<?php require_once('js/custom.php'); ?>

Answer 1

Take a look at wp_localize_script. Although ostensibly for translation, it lets you pass PHP values to JS. Here's a fairly good walkthrough on how to use it.
EDIT:
First, ensure that you are loading your JS using wp_enqueue_script, as you will need to refer to the handle. In your functions.php you'd have:
$date = get_option('director_date');
wp_enqueue_script('my-script', get_stylesheet_directory_uri() . 'js/my-script.js');
wp_localize_script('my-script', 'my_script_vars', array(
'date' => $date
)
);
wp_localize_script takes three arguments:
The handle of he script to pass the variables object to. This should match the handle being used in wp_enqueue_script
The name of the variable object you want to create. You will use this name to refer to the object in JS
The array of variable to pass to the object. Here I'm just passing the $date variable we declared earlier, but you can obviously pass whatever you want.
Then in my-script.js, you'd access this object very simply:
var $date = my_scripts_vars.date;
alert($date); // Or do whatever you want with it

Answer 2

In index.php, you can do something like:
<?php $date = get_option('director_date'); ?>
<script type="text/javascript">var generated_date = '<?php echo $date; ?>';</script>
Just make sure you do this before you include the JavaScript where you want to reference the generated_date variable you just created.